When you created your leaf from a plane, the planes origin default to dead center. Sapling assumes your leaf's origins is at the base of the stem. Since your origin is in the center, you'll get the misplaced leaves shown in your image.
To fix this.
- Put Focus on plane/Leaf
- Set "Pivot Point" (it's found at the bottom of your blender screen" to  "3D Cursor"
- Click your cursor to bottom of the leaf stalk
- On left side of screen, select "Set Origin" >> "Origin to 3D Cursor".

That should take care of your problem.


to add an hdri go to the world tab and add an environment node to the surface output, you can copy my basic setup it gives you some flexibility.


I was impatient; blender is pretty slow on my machine. Just close and restart every now and then.


Moving object while following it with camera

You could try using a camera object and locking the camera object to the view in the side panel settings when selecting a camera object (under view).

When you go into camera view (numberpad 0) it will move with the 3d camera.

Edit* You can setup multiple cameras this way and scroll through them by setting markers in the time line.


My Answer:

This sounds at first as if some drivers are not installed in the optimal version or sth is missconfigured.

My Advice:

If you are an inexperienced Linux user, you will have a hard time avoiding independent google and building up a certain technical understanding. Part of this is to better isolate your problem than "... my system lags, Blender crashes, etc... [...] blender crashes all the time... My 2013 old Imac did better than this"

Start by familiarizing yourself with your graphics card driver.
https://wiki.archlinux.org/index.php/NVIDIA

When you narrowed down your problem and cant find a way to fix it ask at https://unix.stackexchange.com/

A general hint which is completely at the wrong place here but might help your actual goal: Arcolinux is based on Archlinux. This is advertised as "A simple basic system can be extended almost arbitrarily according to the needs of the respective user". Arch is a powerful tool especially if you want to create a minimalistic operating system for special requirements. There exists distributions where beginner friendliness is a bigger goal than custom experience.


To sum it up:

Creating a vertex group is just saying that this group of vertex will have this name, it can be useful for several purposes, some groups will be useful to parent the vertices to an armature, others for particles, etc...

You can create as many vertex groups as you want, and each vertex group is independent from the others. For example some vertices can be part of several vertex groups.

To create a vertex group click on the « + » button on the right of the Vertex Groups list, give it a name and select this group. If you haven’t any vertex group yet and you begin to paint in Weight Paint mode, it will automatically create a vertex group.

To choose the vertices that will be part of this Vertex Group you can either do it with Weight Paint mode with the brush, or in Edit mode with the Assign button below the Vertex Groups list.

A vertice can be only 50% (or 70% or 10% or whatever %) part of a group, it means for example that when you assign an effect to this group, this part of the group will only produce 50% of this effect.

When you paint in Weight Paint mode, only the part that is red, yellow or green (i.e. not blue) is assigned to the vertex group that is selected in the Vertex Groups list. The more the zone is red, the more it is 100% part of the vertex group. The blue zone is not part of this selected group, but it can be part of another vertex group: select the other vertex groups of your Vertex Groups list to check it out.

If you want to create or modify a vertex group in Edit mode, select a group of vertices and click Assign under the Vertex Groups list. The Weight factor will determine how much weight you want to give to some vertices, if you want them to be 100% part of this group (equivalent to red), or only 50%, etc...

I hope it answers your question...


Orientation of instances in Particles Instance Modifier

Tassle_twist.001 has a particle system applied to it from the Modifiers tab. That does'n seem right. remove it, then select the belt and from the particles tab section Render select Object instead of Path and select Tassle_twist.001 as Dupli Object. Now go to the Physics section of the Particles tab and set the size to 1. It's not entirely clear to me what you want or what you're having trouble with exactly, but I hope this helps.


Horizontal lines showing in volume scatter shader

Volumetrics shader are simulated by "overlaying several layers of thickness". These are called samples. From the Blender reference manual's page:

  Step Size: Distance between volume shader samples when rendering the volume. Lower values give more accurate and detailed results but also increased render time.

Here's a default UV sphere showing the steps:

Your scene is quite big and deep, so you'll have to decrease the distance (increase the resolution) between these "planes" with the Step size property you can find in the Volume sampling panel in Render tab to hide this effect.

The purpose is to get a finer calculation of the procedural texture you are plugging in.


How would i go about creating a material where i can use a color ramp to control areas or total transparency?

use the texture as the factor of a mix node between the surface material and a transparent node.

Hope this helps.


How to scale an extrusion from a rectangular plane equally along all four sides?

Scaling works relative to every single axis.
X is 200cm, 75 percent of that is 50cm smaller than before.
Y is 100cm, 75 percent of that is only 25cm smaller.

Use inset (press 'i') instead - it works with a fixed offset - and move the new face after that.


How do I add multiple shapes to one skeleton

Exactly the same as attaching one shape to a skeleton. Make sure all the shapes are selected, then select the skeleton (i.e. make sure the skeleton is the active, more brightly outlined object). Then hit Ctrl+P to mark the skeleton as parent of the shapes.


Why my render is more noisy if MIS is on and sample rate is higher?

Some links to point you in the right direction:

Ways to get rid of fireflies (White pixels in your render)

Reduce noise in Cycles renders

The noise can be caused by a lot of factors and is a common issue with Cycles.
I've personally found that Filter Glossy and increased clamping combined with more samples work best for me, but it's totally depending on your type of render. But I render a lot of glass myself, so I would assume this would work for you as well. But then again, check out the links I gave you for some good tips.


Using the False Color look in combination with the CDL Node to work on Wide Dynamic Range scenes

The false color look presumes the use of the Wide Dynamic Range View.
Using the False Color with other views in colour management will result in incorrect transform values.

This Wide Dynamic View transform can use approximately six and a half stops above middle grey and map them into the display referred values of 0 to 1.
Here's the histogram of an example scene. It shows 10 gray patches that are darker than middle gray (0.18) and 7 brighter ones. Each patch from left to right is twice the intensity than the previous one, except for the one at the very right that is just one half stop brighter. Note at the bottom left of the image the red arrow, it indicates the area between 0-1 (values used for display referred images).

(click on the image to enlarge)
Once the Wide Dynamic Range View transform is enabled, that wide range of values gets remapped to fit into the display referred range of 0 to 1. Middle gray gets mapped to a 0.60 and scene referred 16.29 becomes 1 (white)

(click on the image to enlarge)
Enabling the False Colour Basic look will allow us to visualize the Scene Referred values within the range defined by the Wide Dynamic Range View.
The mid gray is represented by grey. Brightes values will be represented as red and white, Darkest ones will be black and purple.

The colour scheme is as follows:

Low Clipping = Black Scene Referred Linear value below 0.0001762728758
Ten Stops Down = Purple Scene Referred Linear value 0.0001762728758
Seven Stops Down = Blue Scene Referred Linear value 0.001404109349
Four Stops Down = Cyan Scene Referred Linear value 0.01124714399
Two Stops Down = Green Scene Referred Linear value 0.04456791864
Middle Grey = Gray Scene Referred Linear value 0.18009142
Two Stops Over = Green Scene Referred Linear value 0.7196344767
Four Stops Over = Yellow Scene Referred Linear value 2.883658483
Five and a half Stops Over = Red Scene Referred Linear value 8.150007644
High Clipping = White Scene Referred Linear value above 16.29174024

A possible workflow:
To do a grade on an image that uses a wide dynamic range, start by assessing your scene and think of what parts of the image should be the mid tones.
By moving the Power values on the CDL node try to make those areas fall close to gray or slightly into the green.
Using a power greater than 1 will make the midtones darker. Setting power values smaller than 1 will make the midtones brighter.
Then try to bring your Highlights within the range of the Wide Dynamic Range View
Use the slope for that. If you have areas in your scene that are white, you know that you have reached the clipping point (1) on the highlights, and you'll loose any detail on larger values. To bring those values down use smaller for the slope, and try to get your brightest highlights display as red with only a few white spots for the areas you want to preserve detail.
Quoting @troy_s When using False Colour, the goal is not to necessarily always bring all values into the display referred transform, but rather bring the reasonable values you expect into the view.
If you see black on the false color, you have reached the clipping point on the shadows. To preserve information on the shadows you want more purple and blue.
One thing to look for is that using small power values, might also affect your highlights and push them past the clipping point. If that is the case reduce the slope value to bring those values back.
NOTE: To expose the values and do precise numeric editing of any of the CDL controls click on the color box at the bottom of the big color circle to expose the RGB values used for the node's transform operations:

One more note The CDL node expects values in RGB. Even though there are some buttons for HSV and HEX, do not use them, the operations will not work as within the CDL specification.


addon "mesh extras" not available in 2.7

Go to File > User Preferences > Addons
Search for extra
Make sure Supported Level is set to Community
Categories to All
Tick the box at the very right
Optionally Save User Settings to enable it by default
Go to 3D View > Add > Mesh, the icon-less entries are from the Extra Objects addon.


Well I'm not sure what technique you are using to "extrude along a curve".  The array modifier is one way to do it as moonboots mentions.  Another one, which I used to create the image below, is to convert your profile mesh to a curve, then use it as the "Bevel Object" of your arch form curve.  You can then convert the resulting curve to a mesh (as I've done with a duplicate in the screenshot).  You will need to be sure to apply location, rotation, and scale to your objects, INCLUDING the arch curve object, to get this to work right, and even after that you may need to rotate the profile (and apply the rotation) so that the right bits are pointing in the right direction.


How can I avoid colored light reflections?

Yes, by decreasing the number of bounces in Render settings > Light paths:

However, note that this is a phenomenon in the real world, and disabling it may make your renders look more fake or unrealistic.


Weight painting mode right click action differs from time to time

If the armature is in pose mode, and you select the skinned object, it will let you pose the armature if you select any bone. On the other hand, if the armature is in object mode it will take you back to object mode.

Actually, this is standard for all objects in that selection by right-clicking in the viewport will put the viewport in whatever mode that object was last in.

Note that selecting another object in edit mode or particle edit mode will not work.


The first step is to make a cavity in the sand.  I can't tell from your image if you've done that or not.  I used the Boolean Modifier (to save time) in order to make this hole the same size as the bottle, but you can also model it which would be more beneficial in the long run:

Adding more bounces to any of the Light Path inputs will result in longer render times and has diminishing returns.  I would set the Transmission bounces to around "5" since there's little difference beyond that:

What you really need is a node setup that will allow you to adjust how much shadow is cast on the ground and in the hole.  This node tree has been around the block a few times and it's still just as effective.  Adjust the Multiply factor to remove shadow caused by the Glass Shader.  Zero is full shadow, one is no shadow:

Here is the final with a factor of 0.8:


How to move modifiers of multiple objects up or down?

Override the context by passing the actual object {'object': obj} to bpy.ops.object.modifier_move_up() or  bpy.ops.object.modifier_move_down() operator.

Example on how to move all subdivision modifiers by name (they are usually called 'Subdivision') of multiple objects to the top (position 0) in the modifier stack:

C = bpy.context
mod_name = "Subdivision"

for obj in C.selected_editable_objects:
    # Test whether there is a modifier called "Subdivision" at all
    if any(m for m in obj.modifiers if m.name == mod_name):
        # Iterate through all modifiers in reverse
        for mod in reversed(C.object.modifiers):
            # Move the modifier as long as its position is 0
            while obj.modifiers.find(mod_name) != 0:
                bpy.ops.object.modifier_move_up({'object': obj}, modifier=mod_name)

Related questions:

Move modifier to the top of the stack through python?
How can I put a modifier at the top of the modifier stack?


Why doesn't my simple mesh wall "difference boolean cut" the door away?

BMesh solver (the one used by default by the boolean modifier) don't like when two faces are coplanar, like the lower faces of your wall and door.

You can move down your door a bit (or just move down it's lower face).

You can also change the solver used by the modifier. In Solver, instead of BMesh, select Carve.


How to fill up every part of a geometry with a fluid?

Select your 'F'

add solidify modifier

move solidify modifier before fluid

bake fluid again (by the way, i use 80 as resolution (much quicker to bake))

and you get:


enhanced 3d cursor. ''..blender redraws itself..''

Yes. When you want to hide the 3D cursor then i would suggest to use the custom Blender build from fjuhec where this is better implemented. https://blenderartists.org/forum/showthread.php?370568-Custom-Build-Blender-pigeon-v2-78a-%28October-27th%29&highlight=custom+blender+build


Export Scene to JSON that has Multiple Models that each have Multiple Materials

I personally would try one of these two things:

Bake an image for the whole object to be UV wrapped in, and then use that image as one material.

OR

Separate the Meshes per material, and export those out separately with their single materials. I know THREEJS anyway has groups that you could use to re-group all of the geometry, but I'm not sure that's what you are using JSON for.


By checking the Transparent checkbox you effectively make the world background invisible. If you want to have the background visible in the render it must be unchecked.


Have multiple parts of model share same UV/texture

Mark Seams in edit mode and uv map as in image above.

Move UV island on top of the other as in image above. You can do a more precise job than I did.  I did not place them on exactly top of each other because I wanted to emphasize that both halves of the sphere have UV coordinates.  I wanted you too see both almost coincident.

If I did a perfect job and the islands were coincident that would be useful too.  So in the image/uv window you might think some pieces of the uv are missing when they are coincident.  That could be confusing.  Islands can be scaled small, merged to same point, or moved off the uv coordinate area.  So again they would be difficult to notice.

Select the vertices of the discussion, view othogonal, so that the vertices line up, then project.

Lastly there are three modifiers you might consider.  UV Warp, UV Project and Data Transfer.


No, video-editor strips don't have their own markers.


Can a Vertex Group be saved as a separate .blend File?

The best way I can think of is, for safety duplicate
the original object first as you suggested,
then remove the other parts of the mesh:

Select the part of the mesh to keep.
Press CTRL + I to Invert Selection.
Press X and Vertices to delete excess parts.

Or (not so good solution) you go back to object mode,
select the object if it is not already the only selection,
and export (for example as collada), and check only selected.
Later you can import the exported mesh.

Or you may give a nice name, like APPEND-WITH-ME, and you can
simply append your other blend file and select that object
(not the mesh, the object). Every material, particles,
etc will be also loaded into the new blend file.


How can I select edge loops with Magic Mouse on a Mac?

Figured it out! Whoo hoo. Turns out this is what I had to do:

Select an edge (using CommandLMB)
Open the Select menu.
ControlLMB (right-click) "Edge Loops".
Select "Add Shortcut".
Press Alt Command LMB, which Blender interprets as Cmd Middle Mouse.

It seems that Alt LMB emulates the Middle Mouse Button. Not only that, mesh.loop_multi_select was the input I wanted, not mesh.loop_select, as I'd originally thought.

After I added that shortcut, this new input setting appeared in my user preferences:

All is not lost for Magic Mouse users.


How to orient the camera to show the object exactly in the same way your eyes are looking at it

Having your Camera selected press CtrlAltNumpad 0.

When objects are clipped you need to increase Camera Clipping range in Camera tab (you will need to have Camera selected):


How to show different images based on Object ID

Here's a solution using OSL to read from multiple images based on the Object Index.

Enable OSL and paste the following into a new Text Editor datablock named something like dynamic_texture.osl :

shader dynamic_texture(
    vector Vector = P,
    string FileName = "",
    float Index = 0,
    string Suffix = ".png",
    output color Color = color(1,1,0)
    ) {
    int _index = (int)Index;

    Color = texture(format("%s%i%s",FileName,_index,Suffix), Vector[0], Vector[1]);

}

In the Node Editor you can now add a Script node and point it at the new Text block. This should create you a new node with inputs for Filename, Suffix, and Index. This can be used to feed the Object Info Object Index to dynamically select the required texture from a set of images :

Note that the filename is absolute in your filesystem - so you need to specify the full path - or prefix with //to specify a relative path in relation to your saved .blend file (eg, //rendered/ for a local subdirectory named ‘rendered’). In my example I placed the files in c:\users\rsedman\Pictures and named them 1.png, 2.png, 3.png, etc. The Suffix indicates the filename suffix - in this case .png.

EDIT : In order to allow for multiple 'frames' per image set you could amend the OSL shader code to the following :

shader dynamic_texture(
    vector Vector = P,
    string FileName = "",
    float Index = 0,
    float Subframe = 0,
    string Suffix = ".png",
    output color Color = color(1,1,0)
    ) {
    int _index = (int)Index;
    int _subframe = (int)Subframe;

    Color = texture(format("%s%i_%04i%s",FileName,_index,_subframe,Suffix), Vector[0], Vector[1]);
}

This will add an additional 'Subframe' input to the socket and the filename will now be built using the subframe as an additional suffix (with up to 4 leading zeros).

For example, setting the Filename parameter to '/tmp/images/', the Index to 3, the Subframe to 26, and the Suffix to '.png' will pick up the image from /tmp/images/3_0026.png. In this way you can use the node to pick out a particular frame of your particular set of images. To drive this from an MP4 video you would need to split out the individual frames and name each file appropriately.

This can produce the following result :

NOTE : I don't know exactly how OSL manages memory and file access when accessing multiple images in this way - there may be a noticeable practical limit of how many images can be accessed by an OSL shader. If nothing more, it will certainly require a significant amount of additional memory to cache a large number of images.


Area Lights disappearing when rendering image

It is not easy without the scene of Blender, but I try to guess the problem, which I think can be solved by checking the outliner at the top left, looks, if the camera is active for rendering that light.


Welcome to Stackexchange! You are trying to transform polygons based on weights of vertices, so your current approach wont work as you expected.

Instead, you need to somehow compute a weight for each polygon based on the vertices that make it. One way is to take the average of the weights of the vertices of each polygon. To do so, loop over the polygon indices, get the weights at those indices and average them:

Then you can use the Offset Polygons node to transform the polygons based on the custom falloff just as you did. There is no need to extract the polygon info or recreate it, the Offset Polygons node takes care of this:


How do you extude along a specified axis?

Specifically when in edit mode and wanting to extrude along a specific axis orientation, you can set Transform Orientations to cursor.
Then in the view panel, set the cursor rotation to the orientation you want to extrude along.

Then simply extrude. Pressing the key E starts an extrusion, then you press the axis key you want ie Z, you can use mouse to set visually, or  then just enter the number value.
Press Enterto commit the extrusion.
Alternately you can set Transform Orientations to normal, setting Transform Orientations to local will refer to the objects transform orientation.


A procedural displacement, shader-only approach, using the HexGrid node group discussed here

The 'Cell ID' output is used to produce a UV into a Noise texture, to generate a random value
That value is used to rotate the Cell UV's, per cell.
The U is extracted from the rotated UV, to produce a gradient across the cell, in a random direction
The 'Distance From Edge' output is used to subtract from the displacement value, to give a slight bevel on the edges of the hexagons, which cleans up the near-vertical sides of the columns, and sink the cracks between them


How to merge two crossing faces into one?

For such task there are Mesh > Faces > Intersect (Boolean) and Intersect (Knife) tools in Edit Mode, but for your example they are not working as supposed to. Also with two separated shapes from your example Boolean Modifier (Union) isn't working as well. I can't say why, as I'm not using Booleans at all.

As a workaround you can make it using Knife Project tool.

Select one of your shape/face in Edit Mode then use P > Selection.

In Object Mode, select one object, then with Shift select second one and go to Edit Mode.
In the Tool Shelf choose Knife Project.
Repeat steps 2 and 3 but now select objects in different order.
Join both objects Ctrl+J.
In Edit Mode select all then W > Remove Doubles and use X > Limited Dissolve.

  Note: Consider using quad topology as this will save you some problems
  later on. Working with ngons could be problematic.


How to render a hdri on a separate layer

If  you simply enable the environment pass in a renderlayer, or add a single renderlayer using an empty scene layer to do so, you can achieve what you would like if I understand correctly what you are trying to do.

You will need to use transparent background, as you will need to use an Alpha Over node to combine the renderlayers to create the complete image.

Here is a simple example:

Click to enlarge

The sphere is on it's own scene/ renderlayer and not denoised, while the monkey and plane are also on their own layer, and denoised. As you asked for a separate layer, the hdri uses an empty layer with the environment pass enabled.

The critical part, as noted is using the environment pass to be able to retrieve the environment image after rendering.


When you're weight painting, you're painting into Vertex Groups.

The vertices you can't paint don't belong to  a group.

There's a difference between a vertex belonging to a group with 0 weight, and a vertex not belonging to a group at all.

If a vertex is not assigned to the active group, you can't paint into it.

Assign vertices (with a given weight) to a group in the Data tab > 'Vertex Groups' panel.

It's very confusing, because by default, unassigned vertices are colored blue, like 0-weight vertices.

You can fix that.. in the Overlays dropdown there's an option, even more confusingly called 'Zero Weights'. (IMO, it should be called 'Unassigned Vertices'.) Anyway, you can use it to display vertices unassigned to the active group, or those unassigned to any group, in black, not blue.


Boolean
The Boolean modifier needs a closed mesh to work properly, see the wiki:

This means that this modifier will only work properly for the
intersection of faces of the two meshes that will result in another
closed loop of edges (filled with faces), creating a new resulting
face topology.

(You can have an open mesh as long as the open parts do not intersect or interact with the boolean operation)
Removing the middle section of the cube should fix it:

You may also need to recalculate the normals (CtrlN)
Also ensure that:

The Modifier is applied to the cylinder.

The Operation is set to Difference:

Knife
In addition to the Knife project tool mentioned by Haunt_House, You may want to use the Knife tool for this:
In edit mode, press K to start the knife tool and C to enable Angle Constrain. (you may need to hold shift at some points to place a cut, due to the view not being aligned perfectly to the topology)

Modeling
Another simple way to do this is to use Loopcuts:
Press CtrlR and use the scrollwheel or the keyboard to set the number of cuts:

You can then use Edge slide (GG or CtrlE> Edge slide) to slide them into the correct position:

An advantage to this is that this does not produce N-gons (see this)


Considering you have hundreds of pieces like this, I am not sure this approach is good enough, but this is the best I have found so far.

The principle is to use a small square with an array, make it follow the curve and shrinkwrap it :

That can be also done using a bevel object with the curve, but the array allows to handle easier the polycount.

Doing that, the main problem is to align the twist / tilt of the curve so that all is aligned along the arm (same problem with a bevel object).

So I had to tilt Ctrl+T each vertex of the curve to align the band with the arm :

Once done, apply the modifiers and you can refine the model (a bit), for instance adding curve and stretch it a bit :


Select multiple items that are listed together in Outliner

The selection method you describe is now implemented in Blender 2.81, together with Ctrl-left-click selecting (Cmd on a Mac), to toggle between Active and Unselected states for individual items.

B Box selection is also available, as in the viewport: left-drag to select, middle-drag to deselect.


How to add hair particle to ocean modifier?

Move the particle system down the modifier stack, so that it comes after the ocean modifier.
(Use the Triangle icons to the right of the modifier to re-arrange the order)

Then, on the particle system settings enable Use Modifier Stack

From the Blender Manual:

Use Modifier Stack
Take any Modifiers above the Particle Modifier in the modifier stack into account when emitting particles.


Texture Paint won't paint the whole face - Bleed option seems to be off

Indeed it seems there's been a regression since 2.76. I reported it here https://developer.blender.org/T52453

Meanwhile, here's how the bleeding algorithm works on triangles :

this explains the non parallelism between the UV edge and the bleeding edge

since the regression, the bleeding treats a quad as 2 triangles.

In any case, most of the times, the best method is to not use bleeding, but paint on a transparent image, export it, import it in the compositor and feed it through an Inpaint node. This gives an even thickness and prevents bleeding in other islands or inside the same island.


Adding selected objects to active keying set

I finally found in the scene panel that the data path should just be "location", so my code sould be:

import bpy

scene = bpy.context.scene

ks = scene.keying_sets.active

for obj in bpy.context.selected_objects:
    ksp = ks.paths.add(obj.id_data, 'location', index=-1)
    ksp = ks.paths.add(obj.id_data, 'rotation_euler', index=-1)
    # "rotation_quaternion" for quaternion mode

Now it works !


Try enabling Dyntopo and turning the Detail down. Dyntopo adds geometry as you sculpt, and lower detail means smaller pieces of geometry, hence more detailed. In the image below, the bulge to the lower right has the default level of 12.00, 5the one to the upper right has 0.50 and the one to the left has 2.00.


How to copy pose or keyframes to other armature with same bones structure and naming?

Copy Pose and Paste Pose

The arrow indicates the icons.  Menu choice is available.

You must be in Pose Mode of both armatures to use the operation.


How do I restart the scene when no collision for 5secs (BGE)

Whenever your character measures a collision, you send a message "reset timer".

Have one object with a timer property (which measures in seconds).

When the property exceeds 5.0 you restart the scene (property sensor greater than mode).
When a message with subject "reset timer" is received set the property back to -5 (property actuator Assign mode)

[Edit]
just in case the character detects constant collision, I suggest to enable [True Level Triggering] at the collision sensor. This way the message gets constantly send and the timer gets constantly reset.


How do I fix the two black lines on my mesh?

You have edges going across faces.

Remove the edges that go across these faces by selecting them, pressing x and selecting delete edges.

Next select the vertices that were left behind and press j key to join these vertices

The end result is quite good.


Try to avoid calculations inside loop if we can do it directly, most of the AN nodes are vectorized, which can perform faster than using loop. So we can modify node tree to something like this:

We can completely eliminate loop by replacing Set Vertex Color node with Object Color Output node since object have only one color and by using Combine Colors node instead of  Mix Colors.

If you have stability or crash problems you can inform developers by creating an issue here


I think there is an issue with your premise. The Average Value node works in the compositor by performing operations on a bounded, finite image, with the resolution you set in the Render settings.

In material nodes, however, the vectors you use, and by extension, the colors, are in an infinite vector space. Not only that, but they aren't (by default) quantized. In compositing, there is a finite number of pixels, making it easy to average the image. In material nodes, you can keep zooming in forever, making it much trickier to get an average value1.

So, the answer to your question is that it isn't possible, because material nodes don't work the same way as compositing. If you ask a new question with a more specific problem, though, we might be able to help you find a way to do what you want to do.

1While it is (sometimes) mathematically possible to find an average value over an infinite vector space with calculus, I suspect that would be very tricky to implement in nodes (and probably impossible without OSL).


How do you create a triangle pattern in a plane?

Just to add to Markus von Broady's answer:

Shear the result by -0,5
Scale by √75 (0,8660254...)
Done

Tadaa...


Turns out using a curve is not a good idea i managed to get it working by using bones only as the pole target and still keeping the chain in shape without distorting like how it was before.


Computer Crashed - entire scene replaced with Default Cube

Can  you please try to see

File - > Recover Auto Save

As shown below:

May be listed here for you, Ubuntu may be slightly different.

I hope it will help you :)


How do I copy object data with deformation animations with AN?

Try mesh replicating using Transform Mesh node.

Another Non intuitive way, Here armatures and objects are instanced and each armature is set to appropriate objects. For some reason it was not updating as expected. so i used an expression to force reset data. It also caused performance drop :(


Should I UV map a joined mesh or keep the meshes separate when exporting a character to a game engine?

As the weapon its other independent object I would not join it with the character, and you can use as many texture as you want if you have different materials.


What is the Difference between Displacement Node Normal Node and displace modifier?

Displacement modifier: affect geometry directly

Normal map: affects polygons perceived orientation in regard to how they reacts to light

Displacement node: affect geometry when rendered (need to be rendering with cycles and turn on displacement in material settings)


Animated objects as particles - Is there a way to tell them when to start their animations?

In order to do this you will have to make a gradient texture which starts from white and slowly reaches to black with circle emerging from its centre(can be easily achieved by using a color ramp.) Then you will have to unwrap the face you want to apply particles on and place it in centre of unwrap grid and then apply the texture in length of particles under textures tab.
For editing the materials you will have to use only one object to be rendered as hair instead of a collection( if you want variety of hairs you can add displacement modifier and change it to local for random results). After this you can go into material tab and animate the material(press I while hovering over your mouse on color). Later on in animation you can add  random node in material or use multiple particle systems if you want to keep all the colours still there.


How to Properly Unwrap Metaball, Metaball animation

I did it this way and it worked fine for me (but i am using a cube instead of a sphere).

Under - Texture Coordinates - Object - Try to plug in your outer sphere.


Yes, cycles caches BVH (Bounding Volume Hierarchy) files in there when Cache BVH is enabled in Render settings > Performance:

Deleting them shouldn't do anything bad. Cycles will just regenerate these files (though it won't cache them if you disable Cache BVH), which might cause an increase in render times, depending on the complexity of your scene.


Reparent Mouth Rig to Different Character's Armature?

I've discovered a way to do this without having to weight paint again.

In the Outliner Window, drag the mesh for your mouth to the other armature and set the Object as the parent. You'll see that the mouth mesh is still weight-painted to the old armature, but you won't be able to move it in pose mode (yet)
Make sure there aren't any constraints added to the armature from the mouth that you're trying to join to the new armature.
In Object Mode, highlight the mouth armature followed by the armature you want to join it with and hit CTRL+J to join them.
Select the bone parent in edit mode for the mouth bones you transferred over under the armature tab.
In Object Mode select the mouth and Shift-select the new armature and type CTRL+P and parent the mouth mesh to the new armature with empty groups.

That's it. You should now see your mouth has the same weight painting it once had but in a new armature! However, you may have to go into edit mode and translate it a bit to get it to line up properly with the bones.


Mist and depth render passes in Eevee are either entirely white or very little shows up

The depth pass is not normalized, so the colors represent the actual distance to your camera. The values between 0 and 1 will be represented by a grayscale gradient, but everything above 1 will be white.

In order to get a normalized output, you need to map the value in relation to the greatest value, that is to say the furthest element in your scene.

That is what the mist pass does. The values will be mapped to the [0;1] interval so it should render as grayscale.

But then, due to the interpolation which is quadratic by default, elements which are far from the camera will be so close to the upper bound that they will be unrecognizable from the pure white value.

You can change the default distances in the world settings, under the Mist Pass panel :

A solution is to restrict the range, not to [0,1] but to [0,x] where x is a value you can tweak with a math divide node.


How to convert from vertex_color to material and export FBX file

Unity is a game engine, not a vertex editing engine. While you can build or download tools to edit meshes inside of Unity, I'd advise you to stick to Blender for that. Unity displays everything similar to Eevee. If you assign a default material to an object in Eevee it also won't show vertex colors, unless you tell your material to read them. In Blender, you need a built-in node for that, in Unity you need a shader that can read and display them.
https://forum.unity.com/threads/finding-and-using-a-vertex-colors-shader.236366/
Unity will also omit any vertex color information in the build, unless you tell it to keep them.

This option is in the Player Settings.


Strange shift on pixel row while compressing video with alpha channel

Leander : "Your trying to save unassociated rgba in a format, that doesn't support the alpha channel (AVI). Render it with a not transparent background: choose RGB, goto Properties > Render > Film and uncheck transparent."

"This is not a bug. You have to choose a format which supports alpha channels. There are not builtin video formats with alpha in Blender currently (such as Prores), so you have to choose an image format such as PNG, TIFF, EXR, DPX with RGBA selected. It will render to an image sequence."

So  the bug where due to the use of transparency and the RGBA mode on a file format that don't support it.

If you have issues rendering with transparency, i tried to render with alpha using ffmpeg video with the codec HuffYUV, PNG, and video codec #1 which support RGBA but either the quality was too bad either it has the bug that i came for in the first place.
It seems like Blender don't have any proper way to render with an alpha mask. i will edit this comment if i find a proper way to do it without using another soft, anyway i'll solve this subject because the main problem is solved.


Is there some way to increase the thickness of the outline around selected objects?

You do this by changing the Outline Width value in your user preferences under the Themes tab. The maximum value is 5 so if this is still hard to see, you can try changing the color (look for the value Active Color in the same panel) or try adjusting the color of your viewport to make it more prominent.


Probably not in a version that old. It's time to update!


When Subsurface is 1, the Base color has no influence.
Still you can use  radius to extract different colors from the Subsurface color.

Why it doesn't work for you
You're using RGB Blue (0,0,1), so Red and Green cannot be extracted (as they're zero).

Example
I'm using some random Blue containing all three channels (RGB: 0.14, 0.19, 0.8):

Subsurface = 1 (so the base color has zero influence)
I can bring up plenty of Red from my Blue, using the Subsurface Radius.


You need more roughness, your model is too smooth. Try with the Principled shader which is a new node in Blender 2.79 +


How do I make the render lighting look like the materials preview lighting?

The materials preview is not, by default, an accurate read of your lighting because it uses an HDRI (high dynamic range image) to create the reflections you are seeing in the preview.

To fix this, open the Viewport Shading drop-down menu and (with Material Preview selected) you will see the two checkboxes for Scene Lights and Scene World. In this window, you can check Scene Lights to reflect YOUR scene’s lighting and Scene World to switch from the default HDRI to YOUR scene’s world (which I’m assuming doesn’t contain an HDRI).

The angle you are looking at, combined with mostly flat surfaces, without an HDRI, are what’s causing the flatness.

To fix this, start by beveling the edges of those sharp corners (it will add realism too). I would suggest adding a Bevel modifier to accomplish this.

Second, look into adding an HDRI so that the flat surfaces have something more nuanced to reflect.

Third, just make sure that your material’s Roughness value is low (.01 to .4ish) as well.

Fourth, in your Eevee settings (unless you are rendering in Cycles), make sure Screen Space Reflections is checked.

Hope this helps.

John


What UI panel property type is this and how can I create my own

That is an Enum Property, essentially an array of options that have an identifying name, a displayed name, and a description (shown in the tooltip).

For example:

bpy.types.Scene.MyEnum = EnumProperty(
    items = [('one', 'One!', 'The first number'),
             ('two', 'Two', 'The second number'),
             ('three', 'Three', 'The third number')],
    default = "one",
    description = "Pick a number",
    name = "Numbers")

For the first item, "one" is the identifier, "One!" is the name shown in the interface, and "The first number" is shown in the tooltip.

You would access the chosen option using scene.MyEnum, and set it using scene.MyEnum="two".

To display the enum in the interface and allow the user to change it, use layout.prop(scene, 'MyEnum')

Note: The code snippets here are very helpful :)


Render your image to OpenEXR MultiLayer format and save the image after rendering.

When saving the image, ensure you have the composite node connected and not a viewer node connected, or the layers will not write.

Doing this, you can open the image at any time for further post processing or grading by simply adding an image node, and you will have access to all the passes and render layers from the image.


Yes you need to unparent the IK controller, otherwise it creates a bug because the bone that is controlled is not supposed to control its master.

Also:

I would put the controller vertically so that you don't confuse it with the hand.
Parent the hand to the controller if it's not already.
If you want the hand to stick to the forearm, give it a Copy Location constraint with the forearm as Target with a Head/Tail value of 1 so that it sticks to the tail and Space > Pose Space <-> Pose Space.


Is there anyway to create/terminate objects on an array, or have a render border per object? Or anything to this effect?

Using the boolean modifier with intersect hides all geo outside of the boolean object's bounds.


Is it possible to extrude along a curved path like those made by a spirograph?

You can also use an Array modifier to create a basic design:


Sculpting leads to tear in center (blender 2.8)

first of all, you must apply all your modifiers before going to sculpt mode, since you have a good base mesh, I recommend you to apply the mirror modifier, and replace the subdivision with the multiresolution modifier, which allows you to sculpt in a good amount of detail, give it 4 or 5 subdivision and everything should work just fine for you. Regards.


Animating the camera's focus during a render with motion blur

Motion blur is separate from Depth of field (camera blur). The object will only be more in focus if either the motion blur is turned down or there is less movement of the object relative to the camera.


\2 is interpreted as an escape sequence started by a backslash (like \n is a newline). Use a raw string literal, r"\Blender Foundation\Blender\2.91\scripts\addons\Mold_Generator_Addon", if you want a string where backslashes are interpreted literally.
But you should use os.path.join (or pathlib) to make paths anyway. os.path.join("Blender Foundation", "Blender", "2.91", "scripts", "addons", "Mold_Generator_Addon")
But you shouldn't be hardcoding the path anyway. You can get the path to the directory containing the current .py file with os.path.dirname(os.path.abspath(__file__)). This works no matter where it is installed and no matter the Blender version.


How do I Make a Transparency to Decal my Object? (Blender Render Only)

All you have to do really is save your texture in an image format that supports transparency. Any with alpha channels should do like PNG, TGA, TIFF, or any other supported by Blender.

You can use any image editing software like GIMP, or Krita, or Photoshop to remove the background of your image and make your decal texture.

Then in Blender add a new texture to your material

Under the Properties Window > Texture Tab > Image Mapping change the Extension mode to Clipping

Under the Mapping panel Change the Coordinates type to Object and bellow pick any object in your scene to control the position of your decal.

You may create an Empty type of object specifically for this, then use it to control the position of the decal, move it about, scale it to set the size, and rotate it to match the surface normal.

Have in mind that this will only work in the rendered view, viewport preview is not supported.

Example file


How to keep a mesh in its original position after applying Curve modifier?

The curve modifier makes a given mesh follow a specific curve, this means that the mesh will start at the root of the curve. If you are just looking for a simple bend then i would recommend using the Simple Deform modifier instead. Simple deform lets the mesh retain its original position.
Alternatively you can parent to curve to the object so that the root is always at the origin of the mesh being deformed.


Blender smoke cache saved but won't load as should after Blender is closed

smoke usually has to be calculated from frame 1

If cache isn't showing try selecting the external folder again via cache menu. Have animation cursor at frame one when doing this.


How to move selected object to the curser location using a python command?

Cursor location is global

The location of the cursor can be considered as "global coordinates".  The cursor has no parent. When the cursor location is set to zero, it sits at the scene origin.

An object's location is relative to its parent.  Its "global" or "world" transforms can be gleaned from obj.matrix_world.

To get an object in the scene by name

name = "Foo"
scene = context.scene
obj = scene.objects.get(name)

If there is no object named "Foo" obj is None

To move the object to the cursor location.

obj.matrix_world.translation = scene.cursor.location

To align both location and rotation to the cursor (Note assumes obj has unit scale)

obj.matrix_world = scene.cursor.matrix


Where do the collections go in 2.8+ when you hit Ctrl-G to make a group?

Okay after a lot of digging it appears that Ctrl-G not creating a usable collection is actually known by the developers: Blender developer discussion thread.

Some of the devs on that thread say it needs to be fixed since the "Create Group" hotkey does nothing perceivable by the user. Others appear to want to leave it the way it is so that it can be used for a new "Common groups" feature when it is implemented. The discussion has been going on for about half a year and the current status appears to be that Ctrl-G does not do what one would expect from reading the documentation. At least I'm not missing something obvious.


How to translate objects away from an empty?

To disable the scale of children objects, you need to add object constraint Limit Scale to each one of those objects.

In the object constraint enable minimum and maximum on all the axes and change them to 1.

Once you resize the parent object, the position of the child objects will change relatively but the size will remain the same.


How to parent facial features to body so rigging doesn't mess up?

Parent eyes to a main bone instead of body. Or create 2 new bones for eyes, if you want to move eyes


Motion Tracking: status of tracked pattern in a python variable (tracked vs. not tracked)

As far as I am aware, this is not possible. You could probably edit the C source code to output these variables for use in your script if you wanted to though.

You can view the Python API section of this page to make sure if you want.


You need to check all of the Ray Visibility: settings under Properties panel > Object tab > Cycles Settings dropdown.

The fixed .blend file:


How to make particles change colour over time in Eeevee?

I know of two ways of doing it.
A: Add a "time node" using animation nodes, and point in "frame" to some math node then to "color"

B: Use Key Frames on the Color ramp. Click on the first color, set to the frame you want that color to be, in the shader, mouse over the color bar, press I.  Change frame, change color ramp color, mouse over color bar, press I.

NOTE: This changes all the particles color at once.
Note 2: The color ramp, as you have it, won't show up in Eevee, but will in Cycles.

This is similar to: How do I get particles to change color over time?


How to make an Emission material transparent?

one option to have transparent could be Adding a Fresnel to your Materials.
But i'm not sure if that's the look that you need for your project.

If you need more bloom, you can play with the render settings too.


Blender 2.8 how extrude Z axis on imported SVG

ok, at the very bottom of this, helped answer my question.
Extrude on Z axis

"Also make sure you "apply scale" (CTRL+A) to make extruding work as expected. "


How can I get the number of vertices/triangles per object?

If you Tab into edit mode with the object selected, the poly count changes to the object.

Before entering edit mode:

After entering edit mode:


The right way to create a rectangle hole with rounded corners on some surface?

If you're working with subdivision, something like this is all you need:

As you can see, you can loosen or tighten the curve by bringing internal holding edges closer to, or further from, the corners, or dispensing with them altogether.


How do I re-size (scale) a model with the textures applied at the same time?

Textures follow UVs which in turn follow your model's vertices wherever they go (assuming your model has standard UV mapping as opposed to projected UVs), so scaling the model will have no effect on your texture resolution or placement.

Best practice generally is to have the pivot points - aka origins - of both mesh and armature at centre - 0,0,0 - although it's not essential, just neater.

Assuming you have that, scale your entire mesh in edit mode, ideally from cursor and cursor placed at centre until it fits your armature-  you may need to move it in Y to align with your bones.

Alternately scale all your armature bones up in edit mode, again from centre, although that will affect any animation already on it, so scaling mesh is a better option.

Either way you may need to tweak the position of the bones in edit mode to match you mesh if there are small mismatches. Animation is likely to be the same for small changes as the position of bones in edit mode are considered 0,0,0 in pose mode regardless of world position.

Hope I understood the question correctly .....


Welcome to Blender Stack Exchange!

In the settings at the bottom right you have Smoothness set to 2. Setting that to 0 fixes the issue.


Should I use Blender 2.44 rather than the latest version of Blender?

Downsides to using blender version 2.49 or older:

Interface is very different than versions after 2.5
Materials are set up differently, some of the functions have other names.
Animation and rigging will not translate properly to newer versions.
Keyboard shortcuts are different.
Most modern plugins will not work. Python scrip terms and versions might not be compatible.
Unstable, and has more bugs.
Possible incompatibilities using modern hardware or modern Operating Systems
No Cycles rendering possible.
Lacks major features to reduce time consuming tasks.
Some tutorials will use features you have, but you will have trouble finding them.
Many users on BSE, and on-line forums will not be unable to help you, as a lot of use never used that version (Surely a few have though)
Harder to find support.
If you find a bug, or blender crashes, you cannot report the crash/bug, and will have to find really old topics for help, or just end up working around the bug.
Generally not a good idea
Once you master the old version, you'll have to forget what you've learned and start over to learn newer versions.

Upsides to using older version:

Perhaps some features you loved are there that they removed (and if there is you can probably find someone made it into a plugin somewhere)

some plugins for older formats only work on older versions.

A different look.

Feel free to edit in other upsides/downsides.


Do I have to setup everything again after update?

Starting at 2.52 blender started saving it's startup.blend file in a new folder for every version. When you first run a new version of blender it sees that there is no startup.blend for it and looks for the previous version then gives you an option to copy the previous settings. I think this may only look for one or two previous versions, so if you update from 2.63 to 2.70 you may not get this option.

This manual page describes the locations that the startup.blend can be found. You can easily find the current startup.blend (and userpref.blend) and delete it so that you will get the option to copy previous settings. You could also locate an older startup.blend file and copy that to the new version folder.

On linux, the folder is located at ~/.config/blender/

On OSX, the folder is located at /Users/{user}/Library/Application Support/Blender/

On Windows, the folder is located at C:\Documents and Settings\{username}\AppData\Roaming\Blender Foundation\Blender\


Perhaps something like this is closer to what you're looking for?

I think this is pretty close to what you've used, but feel free to check out what I've done here.

Transmission = 1

IOR = 1.05

Roughness = 0.167


how to make new object from the duplicated part of other object in edit mode?

Select mesh and press P> Selection. In object mode, to join the mesh press Ctrl+J.


It looks to me like a problem occurring during playback, it's not part of the file.

The distortion is inconsistent between playbacks, and I've only seen it (sometimes) when using VLC. mplayer has no problems.

I don't know if there is anything you can do, this looks like a problem with the program doing the decoding.


Safe Area marks for the frame can be toggled with the safe Area box on the camera settings

But in the image on the question there are no "safe" marks: the red outline appears when you lock your camera to view or when you use a render border. In the first case press N to access the View section and uncheck "Lock Camera to View".

If you are using a Render border you can clear it with Ctrl+Alt+B.

If the issue is that the camera view (the brighter rectangle) is too small on the screen, then press Home to have the camera view fill the window.

(This works even when the camera is in locked to view mode).

If the camera is not locked to view, using the mouse scroll wheel (Or Numpad + and  Numpad - or Ctrl+ and Ctrl-) will make the camera view larger (or smaller) on the screen.

The other lines on that gigantic motorcycle are likely lines of objects that are parented to each other.


looping animations inside a project without copy pasting keyframes

To make an animation cyclic, select the action in the Dope Sheet and press shift E > Make Cyclic.


The problem here is Lens Distortion Filter you added in the Compositor. Because these distortions are calculated on color values (especially dispersion), the transparent area is taken as RGB 0/0/0 i.e. black.
To get back the transparency, you could plug the Alpha output of the Render Layers node into the Alpha input of the Composite and Viewer nodes.
Of course in this case, all distortion / dispersion that extends the alpha of the original image will not be visible because it becomes transparent.
You could take the original Alpha and mix in a copy of the Lens Distortion node before plugging it into the Composite/Viewer alpha, this helps but dispersion doesn't look the same as on black background.
See the attached image for comparison:

If you use the original alpha, the silhouette of the cube isn't distorted, the dispersion is almost invisible except for some skewed looking edges.
The alpha with dispersion takes the distortion/dispersion into account and makes the distorted part going from opaque to transparent according to its brightness.
This is how the dispersion normally looks on a black background and how it's calculated on a transparent background.
If you take the result from 2. and alpha over it on a black background it comes close to the real dispersion of number 3. However, it's not as colorful because of the transparency.
Here comes the problem: since real dispersion is splitting up the colors into spectral colors, on a white background it looks quite multicolored.
But if you just take the dispersion from the transparent image and alpha it over a white background, the multicolor is gone since the dispersion only worked on the blue of the cube and not the background.


Is there a keyboard shortcut to open and close these areas?

Just keep the cursor in the 3D View and press Shift+spacebar.


Render an animated object inside an irl video

You are looking for a tutorial like "match track blend"

https://www.youtube.com/playlist?list=PLtuvwW4VAp5tu2RdbRHThM6FVFfvFur1g

and simpler from Blenderguru

https://www.youtube.com/watch?v=wjWoglMYXBE

which is to comprehensive to be covered in a single answer.

As you seem to be fairly new, I suggest you look through the list

Resources for Blender


Adding a driver to a Cycles node via Python

You need to add the driver on the output, not the node directly:

fcurve = node.outputs[0].driver_new("default_value")

or

fcurve = node.outputs['Value'].driver_new("default_value")

The driver expression is accessed like:

fcurve.driver.expression


You could begin with the top spiral, making sure that your edges follow the slots, so that it's easy to extrude or add edge loops:


How do I make custom grass using particles?

Well after hours of looking things up and getting frustrated, I realised that the origin points of the grass were set to the top and not the bottom. Problem solved!


Check CGmatter tutorial on youtube :https://youtu.be/gz4qV5_zuMo
Or you can use gimp to crop the image


Color of curves and their control elements, question 2

I don't know about the bezier curve thickness, but for the rest of the changes take a look below.

Go to user preferences (shortcut: Ctrl + Alt + U).Go to themes on the top and 3d view on the side.

Among these options,(10th row from top), 'vertex select' and 'vertex' will change the vertex colors for selected and non-selected vertices respectively.(both for bezier curves and mesh objects)

And in the 24th row, 'align handle selected' will change the handle colors of bezier curves in edit mode. Other settings for bezier curves, start with 'NURBS'

Scroll down until you see something like this.

'Vertex size' is for the size of bezier vertices and the usual mesh object vertices.


You could continue to retopologize over this incision.
When your retopology is over, you would UV unwrap it, and do some displacement map baking, or normal map baking.

Then you can use the baked displacement (or normal map) textures on your retopologized model. So the incision would not be in the topology, but in the texture (normal map, or displacement). So it would be visible in your render.


Use an image as the texture for a lamp. (See Avoid distortions when creating projector effect)

and add volume scatter to the world (or create a mesh around the scene as voume scatter domain) so that the beam becomes visible.

Click on the image to enlarge.

More info on volumetric lights and scatterning here and here


Cloth effect acting strange when I scale the pinning group

When running a cloth simulation, Blender uses the state of the mesh at the start of the simulation to determine the properties of the cloth - in particular, the size and dimensions of the individual faces. It appears that in your example that you have scaled a set of vertices while in Edit mode and this has affected the dimensions of the cloth itself, rather than just moving those vertices as intended.

In order to resolve this you need to know a little about how the cloth simulation operates. Firstly, the 'base' state of the mesh determines the underlying geometry of the cloth - ie, the vertices of the cloth and the length of any edges connecting those vertices. Once the simulation is started, Blender effectively makes a copy of the entire mesh and moves the location of that copy's vertices based on the simulation - but, importantly, Blender will use the 'actual' mesh edges to limit how far neighbouring vertices can move away from each other - ie, the 'structure' of the cloth. In addition to just the 'distance' between the vertices. Settings in the cloth simulation allow the 'stiffness' of this structure to be set, allowing the cloth to retain it's original shape.

When you 'pin' vertices, you are effectively tying those vertices to the corresponding vertices in the original mesh (rather than the 'copy' that follows the simulation). When you manipulate the original mesh, any 'pinned' vertices will follow where the 'actual' vertex moves. This allows the original mesh to be manipulated to effectively 'drag' the simulated mesh to affect the simulation.

So, to achieve the effect you are looking for, first create the mesh in a form that mimics the actual structure of the cloth - in this case, the curtain is a simple subdivided plane - more subdivisions gives more resolution to the cloth :

Select some of the vertices to be 'pinned' - ie, the points where it would be attached to a curtain rail or whatever. Assign those vertices to a vertex group with an appropriate name - eg, 'Pin' :

Setup your cloth properties with Pinning enabled, specifying your new 'Pin' vertex group.

Now, simply add a keyframe at the start of the animation to set the scale of the entire mesh to 1.0 and add a second keyframe to reduce the scale of the mesh (in the appropriate dimension - in my case this was in the Y-axis only). Since only the pinned vertices affect the simulation it is not necessary to limit the scaling to only the pinned vertices.

This produces the following result :

Blend file included


Rotate bezier handles with Python to face normal

Ok, found a solution: Just adding or subtracting the normal vector to or from the control-point of the curve:

Like before the normal of the face I get from here

hit, loc_hit, norm, face, *_ = scene.ray_cast(context.view_layer, origin, view_vector)

Then I add or subtract it to the control point of the bezier curve:

norm_start = curve_shape.get_normal_start()
norm_end = curve_shape.get_normal_end()

bez_points[0].co = curve_shape.get_start_point()
if norm_start is not None:
    bez_points[0].handle_right = bez_points[0].co + norm_start
    bez_points[0].handle_left = bez_points[0].co - norm_start

bez_points[point_count].co = curve_shape.get_end_point()
if norm_end is not None:
    bez_points[point_count].handle_right = bez_points[point_count].co - norm_end
    bez_points[point_count].handle_left = bez_points[point_count].co + norm_end


CORRECTED FIX: The problem was my Blender export settings. To ensure DAZ gets the normals correct on all faces, you need these settings: where (+) means checked and (-) means unchecked -- and they worked:

Forward (Z Forward), Up (Y Up), Selection Only (-), Animation (-), Apply Modifiers (+), Include Edges (+), Smooth Groups (-), Bitflag Smooth Groups (-), Write Normals (+), Include UVs (+), Write Materials (+), Triangulate Faces (-), Write Nurbs (-), Polygroups (-), Objects as OBJ Objects (-), Objects as OBJ Groups (+), Material Groups (-), Keep Vertex Order (-), Scale (100.00), Path Mode (Auto).


Extract audio to file from movie clip - with Blender?

Currently there isn't a node with that capability built in. The simplest that you might script is the following:

add the clip to the VSE
set start and endframe: bpy.context.scene.frame_start  and .frame_end
call the mixdown operator: bpy.ops.sound.mixdown (see the docs for parameters)
reset frame start/end if you need to.

something like this.

import bpy

def main(filepath_source, filepath_destination, frame_start=0, frame_end=20):
    scn = bpy.context.scene

    scn.frame_start = frame_start
    scn.frame_end = frame_end

    if not scn.sequence_editor:
        scn.sequence_editor_create()

    sequences = scn.sequence_editor.sequences
    sequences.new_sound(
        name='drone_detroit',
        filepath=filepath_source,
        channel=0, frame_start=0
    )
    bpy.ops.sound.mixdown(filepath=filepath_destination)

fp_source = r"C:\Users\zeffi\Downloads\DRONE\0001-2964.avi"
fp_destination = r"C:\Users\zeffi\OneDrive\Documents\chopper_drone4.flac"

main(fp_source, fp_destination, frame_start=500, frame_end=560)

the sequences.new_sound, lifts the audio track off the .avi.

The mixdown operator will output the audio of whatever is between those two frames.


How can I efficiently duplicate a large amount of objects?

Remove repeated operator calls
Most likely this is a veiled duplicate of
Python performance with Blender operators
Removing 17,000 operator calls will help... ie removing bpy.ops.object.duplicate_move using low level API calls
# copy the object
copy = ob.copy()
# copy and link data, prob not needed here
mesh_copy = copy.data.copy()
copy.data = mesh_copy
# set the local location
copy.location = (0, 0, 0)
# and / or set the global translation
copy.matrix_world.translation = (0, 0, 0) # scene origin

Link to scene in <= 2.7x
scene.objects.link(ob)

Link to collection in >= 2.80
context.collection.objects.link(ob)

In 2.8 for example move_obj can become, (Note there is no need to link them to collection here, could do it later)
def dupe_move_ob(coll, ob, vec):
    copy = ob.copy()
    copy.matrix_world = Matrix.Translation(vec) @ copy.matrix_world
    coll.objects.link(copy)
    return copy

Returns  a reference to the newly created and moved object.
Similarly would change other methods to pass objects
def rotate_object(ob, rot_mat):

Dupli
For 17, 000 objects will still be slowish. As commented consider using some form of dupli for this, eg dupliverts, make one mesh, add verts at all the locations calculated, set their normals (via the rotation) and one object will be duplicated for each vertex aligned to the vertex normal.
Make the new mesh object the parent of dupli object and under   Properties > Object > Instancing choose Verts.
To illustrate a script to duplivert a cone to a subsurfed suzanne.

The vertex normals of suzanne are determined by the faces. If we construct a vert only mesh, then set v.normal = (x, y, z) for each vertex
import bpy
from math import radians
from mathutils import Matrix

context = bpy.context

bpy.ops.mesh.primitive_monkey_add()
monkey = context.object
monkey.modifiers.new(name="Foo", type='SUBSURF')

bpy.ops.mesh.primitive_cone_add()
cone = context.object
cone.scale *= 0.1
cone.parent = monkey
cone.data.transform(Matrix.Translation((0, 0, 1)))
cone.data.transform(Matrix.Rotation(radians(-90), 4, 'X'))

monkey.instance_type = 'VERTS'
monkey.use_instance_vertices_rotation = True


Make imported images insensitive to lighting but cast and receive shadows

Well you see, in reality, shadow is simply the absence of light. So to make something shadeless and receive shadows doesn't make any sense at all.

But of course, there is always a way around the laws of physics :)

There may be a few ways to do this, but the first that comes to mind is compositing:

Your "shadeless" material should just be a regular material with shadeless turned off.

Then you need to give a unique Object Index (or Material index) for the objects with shadeless materials - this will allow to do compositing for only those objects:

Then enable some render passes:

Shadow to give you... well, shadows.
Object Index so that you can isolate those shadeless objects.
Color so that you get the material color without any shading.

So when you render, you'll get:

Plain uncomposited render:

Shadow:

Object Index:

Color:

Then in the node editor, you simply need to multiply the Color and Shadow passes to get your shadeless but with a shadow effect:

And then use the ID Mask node to isolate the objects that you want to be shadeless, and use that as the Fac to mix the raw render and the shadeless part together (so that only the objects that you want to be shadeless are shadeless):

Download the .blend

Note: If you get aliasing issues, enable Full Sample in the render settings.


How to limit object rotation (transform) only on x-axis on my rig?

The axis locks are a UI feature that only provides a simple lock in the 3dview and they are easy to work around. To completely limit transformations you should use constraints. Constraints are the last thing applied to an object, they will limit the transformation values even if you have keyframes on the value that are outside the constraint settings.

For your example the Limit Rotation constraint will prevent rotation on a specified axes, you can also limit the rotation to a range so that you could only rotate the joint 45 degrees.

A limit with min and max at 0.0 will prevent any rotation, you may also set both at a certain angle.


I'll be describing two approaches, one for the case that you don't know where the blender.exe is located, there other for when you do.

In case you don't know Blender's install directory:

Open the Windows Explorer WIN+E
Navigate to C:\Program Files\Blender Foundation\Blender and verify that the blender.exe is present. If it is continue with step 4, otherwise step 3.
In case you didn't find the blender.exe go back to C:\Program Files and use the search box to search for blender.exe. When it's found right click on the item and select Open File Location.
Click in the address bar that displays the current path and replace the text with cmd. Press enter and a command prompt should open with the working directory set to the path where Blender is located.

If you already know Blender's install directory:

Open a command line WIN+R and type cmd and press enter
If Blender is on a drive that isn't C: you will have to change to the correct drive. You can do this by typing the drive letter and pressing enter. For example if Blender is located in K:\05_Download\blender-2.80-windows64, you would type K: and press enter.
Change the directory to where Blender is located. Use cd to change the directory, for example cd K:\05_Download\blender-2.80-windows64.

Now you can start Blender with the (temporary) factory settings. Once you close and restart Blender without the flag it will load your preferences. This is better than doing a factory reset, when you only need to temporarily disable preference loading.

.\blender.exe --factory-startup

Another flag that is useful in case Blender crashes is --debug which will display debug information on the command line.

.\blender.exe --debug

The full list of command line arguments can be found in the manual.


How to delete 'Mark Sharp' edge properties?

If you used Mark Sharp function, then you probably noticed Clean Sharp just below it. Select the edges and use it (Ctrl+E>Clean Sharp).


It should depend on the "factor" of the mix, citing the manual:
"Fac
    The amount of mixing of the bottom socket is selected by the Factor input field (Fac:). A factor of zero does not use the bottom socket, whereas a value of 1.0 makes full use. In Mix mode, 0.5 is an even mix between the two, but in Add mode, 0.5 means that only half of the second socket’s influence will be applied."


That highlight is indicating the current active object.
I was about to tell you that you can't really do that, since most of that data is read-only, but after some stubborn, extra googling, it turns out you actually can!
bpy.context.view_layer.objects.active = None

I guess we both learned something new today.


Guys I figured out the problem. In blender tab my keybords language turns to English. But only in the blender. But not at the start. I think when I do my models I press some keys then it turns to English. Thanks to @Pullup I solved my problem.


Best strategy for rigging and modelling tongue in face

All the options are equivalent in terms of animation comfort (user interacts with armature only), how they deform (separate or not, the weight painting of vertices can be the same) and materials (you can assign materials to individual faces).

A reason to split your mesh in rigging is to be able to interactively hide parts of it (but this can be also done with mask modifiers on the mesh), or to be able to split it (dismember body parts,..). None apply here.

There are no issues with one armature driving multiple meshes. You can even pack everything up into a group and link it as a single entity with a proxy rig that drives that.

In terms of setting the rig up, having the mesh in one piece is the most convenient, because you have the ability to blend weigh-painting well between bones.


Cancel a bake that freezes UI with black box percentage counter

Just press the Esc key on the keyboard to cancel the bake.

Some bakes have a progress bar in the 'Info' header, these can be cancelled by pressing the small X next to the progress bar or by pressing Esc.


Automatic weight painting does not deform the mesh of my character?

My friend, you have "Face selection masking for painting" enabled. Disable it by clicking on the icon in the red circle on the image attached, and everything will back to normal.


Why doesn't my boolean difference modifier work?

Booleans are very powerful tools but they are very picky about overlapping vertices and edges.
In this case you have a sphere with a top and bottom vertices which have a lot of connecting edges. Top vertex can be seen in attached image. Your boolean will break if the side of your object overlaps with any of these edges.

You could change you sphere to a round cube which doesn't have similar vertices on top and bottom. (To add a round cube use an build-in add-on Add Mesh: Extra objects). Round cube is easier to align with your object. Just make sure none of the vertices and edges overlap.


Cloth texture not rendering properly when animating

It looks like your "Viewport" and "Render" subdivisions are set differently. Depending on how you're rendering, that can make a huge difference at values that low (0-3 really). It may also be affecting baked cloth simulations.

I recommend setting them to the same value. Possibly also bumping it up to 3.


Array modifiers are actually an interesting way of doing this. Start- and endcaps make all the difference.

First I defined the radius with am empty and extruded a circle, rotating it 5 degrees into a wedge around the empty. Then I fitted the start and end cap. Start cap is easy, end cap needs a bit of tweaking.

The rest is another empty that I rotated 5 degrees around the pivot empty to act as Object Offset for the modifier.

Simply adjust the steps in the modifier, duplicate and apply. Pipe factory.

And that's the result:

As long as you don't need a pentagon, the 5° increments will cover most cases.


How to make one object fit into volume of another?

How about:

Make a box
Make a circle which fits the box
Make a Lattice object which fits the box
Assign a Lattice modifier to the circle and the box

Now, whatever you do to the lattice, will happen to the circle and the box.

Or, if you have to fit to an existing box, make the Lattice to fit the circle, and then snap its vertices to the box.


Oops no, @3fingeredfrog was right :
In order to snap correctly to pixels you have to choose the Snap to Pixel option but ALSO have to UNCHECK the snap magnet tool into the main toolbar, or else this will be the main snap overriding the snap pixel option.

Thanks again


I found that this problem originated from deleting the extra materials that came with the exported Waveform (.obj) from Photoshop.  I believe this is a unique problem, probably different from the other "help my object(s) render all black" found around here.

To fix this I simply re-imported the original object and left all 5 materials that came with the object.  It's not an ideal solution for me because I would prefer to have one single material applied to all facets/sides of the object rather than have to manipulate and work with 5 separate ones for such a basic shape, however, this works 100% and addresses the source of the problem thus I'd like to close this out.

Example:

If I find further information regarding how to simplify the object's materials into a single mat, I will post that in a new question and link it here.


Your shader node is a true mess

You have the an Alpha output connected to a Vector socket
The image Alpha is not connected to the group input Alpha socket
You are mixing a a Diffuse shader with a Transparent shader, that will lead to a transparent material, not black plastic
Then you are connecting Shaders (green) to a Color (yellow) socket
You are multiplying shaders, which I am not entirely sure what result it would yield
There is also a group "BaseMaskPlastic" with an unknown Shader output connected to a color socket

General rule of thumb: respect socket colors, match each type of data with it's own type of input, with the possible exception of Color/Value and Vector/Value which can at times be interchangeable.

You are also overcomplicating things a lot. If you want black color in the transparent areas of your image all it takes is one Diffuse shader and one Color Mix shader between the image and a black color and the image alpha as Mix Factor. Something in the like:


How do I sanitze? Pose Library: Error: Potentially corrupt library, run 'Sanitze' operator to fix.

The Sanitize button (and command) did not fix the problem for me.

However, this did:

In Object mode I selected the armature.
I switched to Pose mode, and entire armature was selected.
I hit the spacebar to pull up the command browser, and typed in "pose" to filter the list of commands.
I had tried all the top ones, and it "felt" like I needed to do
something to the "PoseLib" so I chose "PoseLib Add Pose"

The error is now cleared, and I have a Pose Library with a single "Pose" in it.

Blender 2.8 beta


Character physics "jump limit" in bge....!

There is no easy way to do this. Even though there is a jumpCount property you can not edit it via script as it's readable only. However, after some tests I found a hacky workaround that might do it for you, because resetting the gravity seems to reset the jumpCounter. It can by achieved by this procedure:

Paste this script into the text editor.

import bge

def main():
    cont = bge.logic.getCurrentController()
    own = cont.owner
    hero = bge.constraints.getCharacter(own)
    hero.jump()

    # Reset the gravity:
    hero.gravity = 0
    hero.gravity = 30 #default value. You might change this :)
main()

Then use the following setup on your player to trigger the script. Notice that the jumping is also done via the script.


Something I've seen is that the taskbar is known to be inaccurate for showing the GPU usage. You could download something like MSI Afterburner which will allow you to see your GPU usage as it is more accurate. In the past, I've had my task manager saying I'm using 14% when I was using 100% so your problem could be that your GPU is running at 100% but task manager isn't showing it.
Link for MSI Afterburner - https://www.msi.com/Landing/afterburner


How to make a round fence out of an array

Add a Plane and subdivide 20 cuts
Add a Circle and go in edit mode and Press F2 to fill the faces
Now go to top ortho view
Select the circle and then plane with shift select
Press Tab now
Press Space bar and type Knife projection
When it cut the circle Press P and select selection
Now the cut circle is separated. Delete the circle and plane and keep the new cut circle.
In edit mode Press Delete -> select only faces.

Convert the cage now to curve
Add a curve circle and bevel it to give thickness to the edges.


Can you edit vertices/faces on a text object?

It's made up of automatic tracing of a font. So it's its own type.
To convert it into an editable object:

Select your text object.
Hit Alt + C and select to either convert it to a mesh or a curve.


Game-ready hair mesh technique like Zbrush's imm brushes or better

I want  to put this down for anyone who may read this answer for future reference. This was a breakthrough for me, and I hope it may be one for anyone who had similar problems to me.

If you

Don't want to pay money for the hair tool addon,
Don't want to pay money for Zbrush,
Don't want to use a particle-based hair system for Blender,
Don't want as limited control over hair strands in Zbrush,
Or if you just want to stay in Blender,

You may want to consider this following technique/addon. It's called Bevel Curve Tools, and it allows Blender users to use a hair-strip technique similar to Zbrush's imm brushes method while potentially being even better.

In addition to being free, this is supposedly better than Zbrush for controlling polycount for hair strips, easier to control tapering, generally less restricted than Zbrush's method. You can even duplicate a hair strand you may have made with its own beveling, which means you can easily manipulate it to add variation and change it to your liking. I'll be vague here since the video link below elaborates on it in much more detail if you're really interested.

For further details, please consider checking out this Youtube video on how to use these addon. And of course, free downloads to the addons themselves are both on the video's description and will be at the bottom of this post in case you are confident with learning the tool on your own.

Good luck.

Github Bevel Curve Tools Download

Github 2 Blender Sculpt Tools (This is for extra features for Bevel Curve Tools, download this if you think you need it.)

How to use Bevel Curve Tools (Youtube Video)


The dimensions is related to changing the scale of the object in Edit mode, if you want to only change dimensions, you can use edit mode and scale it there. Scaling in Object mode will result in changing both dimensions and scale. Hope that helps!


Animation node - circle generator inside loop

If you're going to replace the mesh anyway, I suggest going with a simple mesh instance (uncheck "Copy from source") in the "Object Instancer" node.

But I don't know why your solution doesn't behave properly honestly.


I want to scale an Object along its local Axis and the return it to its initial scale using the global Axis

import bpy

bpy.ops.transform.resize(value=(1, 2, 1), orient_type='LOCAL')
obj = bpy.context.selected_pose_bones[0]
mat = obj.matrix.to_3x3()
print(mat)
bpy.ops.transform.resize(value=(1, .5, 1), orient_type='GLOBAL', orient_matrix=mat)

This works and I am going to try and explain this. I am sort of newb here so bear with me, and by all means correct me in the comments if I am wrong.
Each translated, scaled or rotated object has a matrix that describes its relation to its original or "initial" coordinates in 3d space.
The way matrices work is they take each vertex's 'initial" coordinates and multiply them by a matrix, giving the vertices new coordinates. Before the any movement of the object happens the object simply has its original or "initial" coordinates located around the origin, Like how when you add a new object it always appears straight up and down and is usually in the center. If you transform rotate or scale the object, then that objects vertices will now be calculated using matrices, until of course, you apply (ctrl A) the scale rotation or position, which will change the "initial" coordinates of the object. Before that the matrices which are being used to describe the objects scale, location and rotation are stored in the object and are available to through the python API.
So what is happening here, is I am getting the bones rotational matrix and applying it to the scale command. So I am scaling in the direction specified by the rotation matrix, which describes the objects rotation from its "initial" coordinates.
But because of the way the matrices are stored, meaning that they include not only the rotational information but also the translation information, I have to use the .to_3x3() to isolate the the rotational part of the transformation.


How do I model something that won't be there all the time?

You could model the wings/spikes at full size, keyframe the scale at your end keyframe, then scale them down until they're so small that they're not noticeable and keyframe the scale at the beginning keyframe.  Then, the objects would appear to grow over time.  Just keep an eye on the point that they're being scaled about so they don't end up accidentally shifting to somewhere you don't want them.
As for modeling them all as one object or separate, it seems like modeling them all as part of the creature would make it easier to rig and animate.  The only issue I could see is if you scaled the wings and spikes by different amounts.  I haven't tried it so that may not be a problem but I would think that, as long as you scale the wings and spikes down by the same amount, it should work fine.  I have modeled different components as part of the same object by assigning them to different vertex groups, that makes it easier to select individual components.


In Object Mode hit Shift+A shortcut to add a new object, and in the menu select Mesh>Icosphere with number of subdivisions set to 1.

Then change to Edit Mode, select everything, hit Ctrl+Shift+B shortcut to bevel the vertices and input 0.35 as the amount of bevel and hit Enter, or in Bevel operator panel change amount type to Percent and change Amount to 33.333%

Result:


How the speed it up a portion of a video, and also all of it?

The video gets sped up as you see but it does not affect the length of the strip.  I do not know a way to automate the process but you need to shrink the length of each strip that you are speeding up.  In your case, you are speeding it up by a factor of 4 so you need to make each strip 1/4 of the original length.

Then you need to move all the strips together so there is no space between them.

I did a search on Youtube using this -  blender vse video speed up

and found this video:  https://www.youtube.com/watch?v=NrX1sK_ZQqs

I hope that helps.


How can I change the X, Y or Z transform values of all a curve's control points at the same time?

A common trick to align things is to scale to zero on an axis.

Select multiple control points
SX0 to align them on the x axis
Change the x axis value to the desired value


To add an image texture to your model you need to follow these steps (There might be other ways, by the way; but this is the way that i would do it):

UV Unwrap your model
Add a new material to it

Add your image texture to the material

And you should be good to go


how to divide one window into two windows

To divide the window vertically click the upper right corner and drag downward with the mouse.  The direction the mouse moves after you start the click and drag determines which way the window divides.

Dragging to the right breaks the window horizontally, dragging downward breaks the window vertically.


How do I control the frames of sprite sheets?

You can specify the start frame in the Image Editor:

If it's coming in in the middles of that animation, we have another problem, because when an object is in a hidden layer, it should not be playing. So this is a bug or something, sorry.


How to scale an environment texture in the world section?

Assuming you have a panoramic background that surrounds the entire scene like you say, then scaling it doesn't really make sense. What you probably want to do instead is move the camera farther back and increase the Focal Length in Camera Settings > Lens:

For rotation, see Rendered environment map is misaligned to World


How to draw grease pencil on a surface (blender 2,75)?

Add a new Grease Pencil datablock in a properies window (N). In Tool Shelf (T) change the stroke placement to Surface. Hold  D and then press and hold the LMB button to draw. Disable the X Ray option if you don't want to see the strokes through the object. To erase, hold  D button and then press and hold the RMB.


Object snaps upwards when trying to link with armature

You shouldn't be setting the parent to the bone. You should be setting "Set parent to -> Armature Deform -> With Automatic Weights" or "With Empty Groups" depending on your needs.


While your Operator.check(...) method returns True the popup will redraw.

Simple return True method used in bpy.types.Operator Dialog Box example.  Setting the boolean prop, my_bool,  to True reveals more in draw method.

import bpy

class DialogOperator(bpy.types.Operator):
    bl_idname = "object.dialog_operator"
    bl_label = "Simple Dialog Operator"

    my_float = bpy.props.FloatProperty(name="Some Floating Point")
    my_bool = bpy.props.BoolProperty(name="Toggle Option")
    my_string = bpy.props.StringProperty(name="String Value")

    def execute(self, context):
        message = "Popup Values: %f, %d, '%s'" % \
            (self.my_float, self.my_bool, self.my_string)
        self.report({'INFO'}, message)
        return {'FINISHED'}

    def check(self, context):
        return True

    def draw(self, context):
        layout = self.layout
        layout.prop(self, "my_bool")
        if self.my_bool:
            layout.label("It's TRUE")
            layout.prop(self, "my_string")

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self)

bpy.utils.register_class(DialogOperator)

# test call
bpy.ops.object.dialog_operator('INVOKE_DEFAULT')


copy/paste (hair) modifier properties (different files)

You can go to File -> Append, browse to your previous file and open the Particle Settings folder to bring over the settings.  Just create a particle system in the new file and slot the settings in under it.


What does left clicking in the 3D view do?

This is the 3D Cursor, and is useful for several things in advanced editing. When you left-click you are setting the position in 3D space for it to be. It works in all modes.

If you would like some more details, go to the Blender Manual.


About the title of the question: you cannot compile add-ons because they are written in Python*.

Your script causes this error because it wasn't registered with Blender. Use the normal way (i.e. the regular Blender UI) to enable your add-on, and be sure to save your preferences so that it stays enabled. Once that's done it should simply work, also with Blender compiled as a module.

(*) Little footnote: Python is compiled into bytecode, but by the Python runtime itself, and doesn't require any action from the user contrary to "compiled languages" like Go or C.


How to Align/Straighten/make Coplanar Non-planar edge between adjacent edges?

Apart rebuilding faces, as I said in comments above, here you find a possible way or sort of inspiration for a more "elegant" method, involving the "magic" Knife tool:

here is a similar setup to your situation:

we're going to use the knife tool to add a "guide" vertex to which we'll snap later, making the two selected faces planar again.

after activating the knife tool, it will show a green square when it "snaps" to a starting vertex: click here.

then, drag until it snaps the end vertex: click here too, then "confirm" pressing enter

note: the knife tool will "cut through" your mesh and create an intermediate vertex just where you need it (you see a preview before "confirming")

now you simply need to activate snap on vertixes, and drag your shared edge (locking Z in this case) until it snaps perfectly to the vertex just created by the knife tool

and now you just need to use "remove doubles" to remove the "guide vertex" we added before, and you're done!

Hth.


How to toggle(Open/Close) `T` or `N` Panel in 3D view Using Python

You can use bpy.ops.wm.context_toggle(data_path) This will toggle N or 'T' panel of whatever area operator was called.
import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        bpy.ops.wm.context_toggle(data_path="space_data.show_region_ui")
        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

If you run this script and call the operator in Text_Editor It will open this side panel.
So if you want to open/close N Panel of view3d from other areas you need to override context. It is a way to fool blender thinking that operator was called in different area.
import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        #copy context
        context_copy = context.copy()
        #loop over current areas
        for area in context.screen.areas:
            #Check if there is 3d view area
            if area.type == 'VIEW_3D':
                #If yes then override context
                context_copy['area'] = area

        #Now pass our custom context.
        #When calling any bpy.ops operator it takes context in which it was called
        #but you can override that.
        #look here for Offical documetation : https://docs.blender.org/api/current/bpy.ops.html#overriding-context
        bpy.ops.wm.context_toggle(context_copy,data_path="space_data.show_region_ui")
        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

Now when you run script and call operator from text editor, it will open n panel of 3d view
HOW TO DECIDE data_path
What I do is go to edit>preferences>keymap
Change search type to Key-Binding and type key which is used in Blender to open/close whatever panel you want. Here I am searching for Tools or Toolbar or T panel in viewport. It can be open using T key. So I searched for it. So Operator call  will be like this : bpy.ops.wm.context_toggle(context_copy,data_path="space_data.show_region_toolbar")


The limitation of baking Shadows is the same currently as with rendering a Shadow Pass in Cycles. The Shadow Pass will only receive its contribution from Blender Lamps. It doesn't work currently with mesh lights, which you are using to emit light into your scene. Try adding a sunlamp just for testing purposes and check if the Shadow Pass then bakes as expected. In my tests here it did. If that works, replacing mesh lights with area lights might be the way to go for you.


Why are the 'Sun' shadows different to other light sources? Blender 2.8.1 Eevee

It turns out that the 'Bias' option for the non-sun light sources needed to be set to the absolute minimum. Everything looks great now.


How do I make a compositor filter effect affect only a specific part of the render?

The mask was limiting the result of the sunbeam node to the doorway itself. You can multiply the mask against the image, then run that through sunbeam and add the result to the original image.


How do I get this character to follow its walking path?

You've confused Object Constraints with Bone Constraints.

If you want your armature to follow a path you need to give your armature a Follow Path constraint. If I check the Properties panel > Object Constraints tab, I don't see any Follow Path. Actually you've assigned a Follow Path to one of your bones, Ankle.L, you will see it if you switch to Pose mode, select this bone and click on the Bone Constraints tab.

So delete the bone's Follow Path constraint and give a Follow Path constraint to your armature. After that press AltG to make your armature stick to the beginning of the path.


How to make this particular blender material in Cycles

If you want to do that in cycles the set up would look like this:

The layer weight node controls the falloff for blue and white respectively in combination with the color ramp to clamp the falloff.

Of course the transparent node is to cutout the center, you might also want to play with the roughness on the glossy shaders, it will give you a different look .


How to deal with a "non manifold edge" high count

If your concerned about non-manifold edges then you plan to 3D print this model. In that case I would add some "material" to the edges being joined. By that I mean some solid printed material that will hold the pieces together rather than a flimsy paper thin join that can break easily.

Start by separating the joined edges. Add a small bevel CtrlB so that the new edge is wide enough. You may want to display edge sizes while doing this, see Mesh display in the properties panel. The width you use here will depend on the material you plan to use, the width of the new edge added by the bevel should be at least the minimum material thickness you can use. Repeat for the other edge.

Select the vertices or edges around both new beveled faces and bridge edge loops (in the specials menu W)

This will remove the non-manifold edges and leave you with a solid join in your printed model.

You may want to bevel these new edges to get a more rounded join.

Another option is to move the cubes together so that both beveled edges meet up and then remove doubles. This will effectively make the corner of the cubes intersect a little and depends mostly on your needs. If your using the array modifier then you can intersect each cube by using and offset a little less than 1.0, I'm not certain if this overlapping non-connected geometry is acceptable for 3D printing so you may have to manually join the overlapping areas.