It all came down to a loss of precision in the depth buffer, let me explain.
You have your camera's Start Clipping set to .001, that is tiny.
If you turn on the display limits of the camera you will start to see the problem.

The camera is in the red box, and your sword is in the blue box, over 60 units away.
Now with the start clip set to 0.001 (the default is 0.1) there is a lot of wasted calculations, leading to a loss in precision.
The blender manual has a note about such behavior with a large clipping range.
This Quote from an article on MSDN explains it well.

The near plane and far plane are the final pieces required to calculate the projection matrix. The more closely together the planes are, the more precise the values in the depth buffer.
The depth buffer can be 16-bit, 24-bit, or 32-bit, with values between 0 and 1. Generally, depth buffers are fixed point, with the values close to the near plane grouped more closely together than the values close to the far plane. The degree of precision available to the depth buffer is determined by the ratio of the near plane to the far plane. Using the tightest possible near/far plane could allow use of a 16-bit depth buffer. A 16-bit depth buffer could reduce the use of memory while increasing processing speed.

So a simple fix, is to set the camera's start clipping to a bigger number, even 0.1 works, but as your scene is currently set up you could go as high as 60.

Changing the camera settings will fix the problem, however you still have a huge sword.
If you look at the dimensions (in the properties panel N) of your sword it is 31 meters tall!
Just scale down the sword with S, until it is about a meter. Then reposition the camera.
The other option is to scale down your entire scene, then change the strength of your lamps.
This has the same effect as changing the clipping on the camera, because there is now less space blender has to calculate.
So really this was a story of way too big, and way too small. Pay attention to your numbers, and even use real world units.


Batch triangulating a model made of multiple objects

separate objects can be edited one at a time, that is what you are doing now.
if you wish to edit all object at once, you can try to join them (ctrl-j) and then go into edit mode. so:

select all objects you wish to edit at once (it works only with objects of the same type, eg: meshes and curves can't be joined, without conversion, which probably you don't want to do...)
press ctrl-j
you have a single object now, composed of all the vertices, edges, faces jou had before. They are now together in the same object but still not connected yo those previously belonging to other objects

Now you can edit the object at once.

When finished, if you have to separate different objects back, you can:

select the joined object
go to edit mode
deselect everything (A key)
select only 1 vertex, from one mesh once belonging to a separate object
select linked vertices, with L key
separate selected vertices in a separate object, with P key
repeat until done


This didn't work because the Texture Coordinates node wasnt added. You should plug one of its output sockets (e.g. Generated or Object) into the Vector input socket of the Mapping node (this is a common approach if texturing anything in Cycles. Otherwise, in Cycles, texture won't appear on the mesh, just solid base color).

Thus you'll be able to adjust the position of the horizon simply by changing Location value by Z axis of the Mapping node (not sure if this is good idea to manipulate horizon like that).

(I changed Location value to 0.3 here).


Beveled edges rendering like they're cut into

Solved it! I needed to uncheck "fields" under Post Processing. What that does, I don't know, but unchecking it fixed it! Thank you!


This may be an issue with the render distance. Can you try extending the camera distance and see if this helps?

With the camera object selected, increase its End clipping distance in Properties > Camera settings > Lens:


Denoising is a great tool, but it is not a miracle button that works equally for each and every cause of render noise. It seems to work better in areas where the surfaces don't have a lot of detail, and the brightness values and colors are more homogeneous.

High contrast areas or with lots of  variation in their values might not fare so well after denoise.

In this example the denoiser is creating a splotchy or smeared image:

The same with fireflies, where the bright spots have very different than their surrounding pixels.

Read: https://developer.blender.org/T52802

There are many causes for noise in rendering, each scene is different, and what worked in some circumstances might not work in others.

But the key thing to be aware of is that denoising will introduce new artifacts, and is certainly not a substitute for a decent number of samples.

Depending on the kind of noise you are dealing with you might get decent results with it along with other tricks, and in some cases not using denoise at all.

Some examples:

64 samples. Horribly noisy and full of fireflies, as expected:

(Click on any  of the images to show full screen)

Compare to 64 Samples with denoiser's default settings:

Most of the noise and fireflies and are gone, but the the noise has been replaced with areas that look blotchy or smeared. New Black artifacts have appeared around the thin and bright areas of the image.

At 500 samples

Image with no denoising:

Compare to 500 samples with default setting for the denoiser. Most of the smearing is gone, but the black artifacts on the bright areas remain.

Increasing the radius makes the problem worse (at the maximum strength of 25 pixels the artifacts in the thin bright areas is worsened).

A smaller radius helps with the black dots around the thin bright areas, but the blotchy areas re-appear to some extent.

Combining denoiser with low values for all of the settings along with some clamping (direct and indirect):

1,000 samples with no denoiser, some clamp direct and clamp indirect:

A lot less noise on and the fireflies are lessened, but the brightness of the scene's highlights has suffered.

Lastly, just for fun, a very clear render at 100,000 samples, no denoiser or other magic settings:

Very low noise, no fireflies and no artifacts... but many hours to render.

As you can see, the denoiser works wonderfully for some situations and not at all in others, having more samples makes some the artifacts introduced less apparent (smear) but does not solve all of the issues with high contrast...

Hopefully this will help you make more informed decisions when to use it or what to expect.

Another example:

100 samples, Fireflies without denoiser.

100 samples: Fireflies with denoiser:

No denoiser, more samples and clamp indirect:

Please read through the following related links and explore the many solutions for noise, maybe one of them will work for your project.

How to avoid noisy renders in Cycles?

Problems with denoising in rendering
How to reduce fireflies in Cycles?

What is branched path tracing and how is it useful?

Branched Path Tracing

What does "number of diffuse/glossy/... bounce samples" mean?

How do I use the cycles Denoiser?


Texture on large objects are just copying/replicating

The topic of landscape texturing is quite big and not easy to condense to format here.

Answer 1:
You aren't using properly tiling texture. When you have properly tiling texture (Texture that has been created/edited to tile/connect to its own border edges) even though it will become repetitive it shouldn't have these sharp edges between the tiles, even at very high tiling.
(To learn more you should google/youtube "creating tiled textures" or "tiling texture" etc)

Answer 2:
Even with properly tiling high quality textures using one texture isn't really enough to create a landscape. Using one huge texture map isn't really usually possible either.

What usually happens is that you will have multiple tiling textures blended together in material/shader. So let's say you want to make a grass field with path in the middle. The field might be texture A and the texture you want to use for the path is texture B. Using enough polys on your terrain mesh you could use vertex color painting to paint the path on the mesh. Then in shader/material you would tell that texture A-Vertex color A, texture B-Vertex color B, this way only the area painted with color B would show the path.

Other common technique is to use height to blend materials. So for example you could blend between sand, grass, rock and snow based on height to transition from snowy mountain top, to rocky mountain, to grass lands and finally to a beach.
Specific workflows for this can be very convoluted based on your platform, though, so again I recommend googling stuff like "material layering workflow" "terrain texturing" and so on.

I hope some of this was helpful.


How can I connect a set of disconnected vertices with a line through all of them

Select two vertices and create an edge between them, repeat for each edge you want.

With two vertices selected blender will create an edge, with three or more vertices it will create an edge between each vertex as well as a face that is surrounded by all of them. If the vertices are aligned the face will be too small to be seen even though it is there.

You could select the vertices from one end to the other and create a face, then use X->Only Faces to only have edges, but this will still leave an extra edge from the first to last, and the remaining edges will only be worthwhile if you select them one by one in the right order, if you use select all then you can get edges between random vertices in the row.

This is a drawback of using the same operator to create edges and faces, the number of selected vertices is the only factor that decides if a face is created, so to create only edges you need to select two vertices and create one edge at a time. As you may want to create edges between all the vertices you have in the grid, you may want to fill in the grid with faces (enabling the F2 addon might help), then select everything and delete only faces to have only edges remaining.

If you enable vertex snapping and auto-merge you could select the first vertex and press E to extrude it and snap the new vertex to the next vertex, then repeat for each edge.


I am having trouble with the Meadow scene tutorial on Blender guru

If you look at the very top of the screen for the tutorial in question, you'll see that is made with blender cycles and you are trying to do it in blender internal. Change it here:


How to prevent meshes from passing through each other?

You need to animate the location of the guitar and hands so that they are in sync with each other. Start with a pose for the body, then place the guitar in front of it and place the hands to match. This could mean adding keyframes every frame to keep the hands and guitar together.

For your character, enable (or create) IK for the arms. This will allow you to place the hands and have them stay still as you move the body. Some child of constraints might help move the guitar and hands together while still allowing the hands to be moved independently. You may want to look at using the rigify addon to create a basic armature that you match to your character, then have it generate a more complex rig that has IK/FK switches etc. You can find some tutorials like this one that explain using rigify in more detail.

If your interests are in rigging then you could look into setting up a more complex rig that could make animating easier, if you only want to animate then focus on animating the two objects so they appear in sync with each other.


This Animation-window-preset should give you the "animation tab".

Alternatively, clicking on one of these items in the bottom-left corner in each subwindow, will open a menu of all availiable Editor-Types.


Where is the viewport render resolution divider?

this patch description (linked from the above D1619 thread) says:

"Cycles/BI: Add a pixel size option for speeding up viewport rendering
This patch adds "Pixel Size" to the performance options, which allows to render in a smaller resolution, which is especially useful for displays with high DPI."

about the UI part the patch shows a new property, called "preview_pixel_size":

this patch  was released Aug 15 2017, but 2.79 final was released september 12 so it couldn't be set for that release, but it is in following releases, such as current "unstable" build blender-2.79-c66983c-win64.zip, in which you can find it where the patch said, under "performance options":


How to animate an object to dissapear (clipped progressively) as it passes through a plane?

Note: This answer is only convenient if your object is made of a single (or just a few) materials, and if the plane it intersects is parallel to two cartesian axes:

All you need to do is to Mix your material (in this case, a simple principled shader) with a fully white Transparent BDSF.

The Mix Factor must be controlled by a Math > (Greater/Less) than node, that compares your object's Geometry > Separate XYZ > [selected coordinate] with a fixed value.

In this example, Z is compared with 0:

Additional notes:

If you are using Cycles and you see some black spots, you may need to increase a bit the number of Transmission bounces under Render > Light Paths.
If you are using EEVEE, your material's setting should have Blend Mode and Shadow Mode set to Alpha Clip.


Losing stairs in other meshes when joining objects

They shouldn't join meshes. One object can have multiple parts. Are you in cycles or render mode? I think your problem is most likely an unapplied subdivision modifier on one object and when you join the others this affects them. To fix this apply your modifiers before you join.
Hope this has helped.

Just a note for next time: please post either the .blend file or screenshots of the problem. That makes it a lot easier to see what's wrong.


The FBX format exported by Blender does not have images included internally, even if you "pack" the images (for including them in the .blend save file).  Your best bet after baking your textures is to save them to real files on disk, so the exported FBX can reference them by name.


you can use Passes/Layers:

Pass 1: Background
Pass 2: Shadow Catcher + Holdout Shader for Object
Pass 3: Object with transparent Background and no Shadow Catcher

Then in your prefered compositing solution you can ramp Pass 2 for a darker shadow and combine then all.


A perhaps simpler way is to use the cylinder primitive.

Add that to your scene,

then in wireframe (Z key), and from the front view,

delete half vertices:

then rebuild top/bottom faces selecting the edge loop and pressing F key

on both sides

then you get

Another way could be to use a boolean modifier, too.


Your grass texture is repeated (tiled) across the surface. If try to texture paint "over", you are actually painting into that texture so the drawing will repeat too.
If you want to blend the gravel painting over your tiled grass texture, you can do it by several methods, for example:

Add grass borders to your gravel texture (gravel fading into the grass), cut the mesh where you want to make a gravel surface and map that "gravel to grass blend texture". Or you can make a segment with this texture mapped and use Array and Curve modifiers to create a gravel path as in the screenshot below... and then merge this path model to the grass geometry. This method creates some seams between the textures so but it can be almost negligible if the transition is painted well. The seams are often covered by some grass / foliage models.

Creating a gravel path using one gravel segment and Array + Curve modifiers

Merged into grass model:

 2. You can cut the area you plan to cover with the gravel, bake the grass texture from this area to a new texture and paint the gravel into it. Search for a Texture Baking tutorial if you don't know how to do it. This method is usable only for small areas because the texture needs to cover all the gravel area so it can become too large for using it in game.

 3. The game engine you want to use may be able to blend textures nativelly (the blending can be for example defined by Vertex painting) ...so take a look in the documentation to see which methods does it support and look for a tutorial.
This is some Vertex Paint in Unity https://www.youtube.com/watch?v=HDXwSEUYrbI


Finding closest distance from point to mesh in BGE

If it's just the distance to the Bound Box, does not require any complex function for this.

I do not usually use bge, but you can take advantage of this code to get the nearest point of a Bound_Box.

#bound.min: smaller coordinates x, y, z of Bound Box
#bound.max: greater coordinates x, y, z of Bound Box
#co coordinate of the point to test the nearest
from math import sqrt
def find_nearest_t_AABB(bound, co):
    nearest = [0.,0.,0.]
    dist = 0.
    for i in range(3):
        if (bounds.min[i] > co[i]):
            nearest[i] = bounds.min[i]
        elif (bounds.max[i] < co[i]):
            nearest[i] = bounds.max[i]
        else:
            nearest[i] = co[i]

        dist += (co[i] - nearest[i])**2
    return sqrt(dist), nearest


Normals are pointing inwards

Solution: flip them.

But: They do look right at your picture.

Transparency enabled.

Solution: disable transparency in the material tab. As your model does not need any transparency this should be no issue.

Mirrored the object. That makes the normals point towards the opposite direction (see the first option). This can happen on negative scale on one or three axis (scale by -1). It is possible you have an according modifier mirroring your mesh.

Solution: Mirror again, scale back, flip normals and/or review your modifiers.


Boolean modifier is the correct option. It is failing because your meshes are not closed. Booleans do not work on open meshes. Select the ending loops of your meshes and press F to add a face. You can delete it again after the boolean has run.


U could make a texture that makes the edges more bright as you see it on real axes:

Here the quick setup - maybe it can help


The play animation button is not part of the Dope Sheet, it is in the Timeline. You've likely merged the Timeline area with the Dope Sheet by accident.
In order to add the timeline back:

Position your mouse courser between the Dope Sheet and the Properties. Right-click and select Horizontal Split.

Change the editor type to Timeline.


Mesh is Weirdly Deformed in Object & Sculpt Modes

I have seen results like this after adding new geometry to an object with a multires modifier. It seems having flipped normals contributes to this.

As your learning, I suggest you delete the multires, go into edit mode and select all vertices, CtrlN to re-calculate the normals, add a new multires modifier then re-sculpt.

If you want to keep your sculpt data the only fix I can come up with is to apply the multires, go into edit mode, select the stray vertices and use smooth to bring them back into place. Press W and select smooth or find Smooth Vertex in the spacebar menu, then use ShiftR to keep repeating the last step.

I think I found a way to reliably re-create the issue so will report a bug.


Sculpting acts on vertices. These are either from the mesh itself (real geometry) or created with Multires modifier / dynamically with dyntopo. However in any case it uses geometry for painting with brushes because by painting you change position of certain vertices. Dyntopo in this case is kind of lazy way since it creates as many vertices as required for currently required level of details, subdividing / collapsing only  part of mesh which is being worked on.
If geometry is uneven sculpting result won't be even as well in case of sculpting without dyntopo. Mesh in the file you attached is one of these examples:

This is wireframe of the mesh in question.
It won't act predictable being sculpted because proximity of horizontal edge loops is enough, while there are relatively small amount of vertical edge loops. When sculpted horizontal displacement will be detailed since there is plenty of geometry, but vertical will be lacking because there aren't as many vertical edge loops as horizontal ones. Since the sculpt will look stretched; inspite of the fact it has ~ 150 000 faces, it isn't really sculptable.
There are 2 general ways from here.
First, un-/subdivide edges of the mesh to get more or less even amount of edge loops in both directions (i.e. to get nearly squarish faces all over the mesh). In Edit mode either dissolve horizontal loop cuts (X > Dissolve Edges), or add more vertical loop cuts (Ctrl+R).
Second, enable dyntopo and set Subdivide Colalpse method of details with proper details size. Note that mesh will become triangulated.
Depending on the case both methods as always have their advantages and disadvantages; use the one which is faster for your situation.


How do I make the camera's depth of field affect an imported image?

The image contains no depth information, to blender it is just a plane, so you won't be able to have any selective defocusing based on the distance to the camera.
If you want to blur parts of it selectively, you need to create some kind of depth map: a black and white image in which the close areas are dark and the far ones are bright.
Then use that image in the compositor. Feed the original image to a defocus node and the fake "depth map" as the Z information. You can use a color ramp to change the values to determine what areas get blurred.

Read:
How can I get a Depth of field render pass?
Blender (Cycles) Manual DOF


Green and red color on my baked normal map appearing

Sometimes the ray distance might not work and will create errors like these. I had the same problem where I will adjust the ray distance and I'll still get these red and green errors. So when this happens, there is the cage method.

Duplicate the low poly mesh and make sure it overlaps the low poly and high poly model and rename it "Cage".

With the Cage selected, go into Edit Mode and face selection mode. Press A to select all of the faces.

Press Alt + S to scale it in the normals. Make sure to hold down Shift so to scale it slowly. Scale it so it encapsulates the entire high poly mesh.

Now, depending on your model, you may have to go into Edit Mode with the cage object so that no detail in the high poly is poking through the cage.
Example: In this image you can see a part of the high poly poking through the cage. So edit the cage so that it covers it entirely.
From this:

To this:

Now go to the Bake panel, click the check box next to Cage and select your cage object.

Bake and see if the green red errors disappear. You may have to edit your cage object again to cover up certain areas the high poly model. Keep editing and baking until your normal map is error free!


You don't have an Output Node for the lamp.

You can insert them manually: Just add an Emission and a Lamp Output nodes.


Best strategy for hiding an object in a scene

The easiest way is to use layers (on the bottom horizontal bar of your 3D View): Select your objet and press M to put it on the layer of your choice. Click on the layer if you want to make it visible, and shift click to make several layers visible.


This is a basic setup of environment lighting (with lots of AO) in BI:

To bake out the AO, just go to the bake panel and select to bake AO...

Of course, you need to do the usual bake stuff for BI (UV unwrap to a valid texture, etc.).

Here are some links for BI:

How do you bake ambient occlusion for a model?

https://docs.blender.org/manual/en/dev/render/blender_render/bake.html#ambient-occlusion

https://docs.blender.org/manual/en/dev/render/blender_render/world/ambient_occlusion.html

https://docs.blender.org/manual/en/dev/render/blender_render/world/ambient_light.html

And for Cycles:

http://www.blenderguru.com/tutorials/introduction-baking-cycles/

Here is my demo blend file (post all blend files on this site BTW):


(modified from this Source)
The script outputs a csv file with the coordinates for each tracker.
from __future__ import print_function
import bpy
D = bpy.data

outputFolder= "/set/your/output/directory/here"

printFrameNums = False # include frame numbers in the csv file
relativeCoords = False # marker coords will be relative to the dimensions of the clip

f2=open('export-markers.log', 'w')
print('First line test', file=f2)
for clip in D.movieclips:
    print('clip {0} found\n'.format(clip.name), file=f2)
    width=clip.size[0]
    height=clip.size[1]
    for ob in clip.tracking.objects:
        print('object {0} found\n'.format(ob.name), file=f2)
        for track in ob.tracks:
            print('track {0} found\n'.format(track.name), file=f2)
            fn = outputFolder+'{0}_{1}_tr_{2}.csv'.format(clip.name.split('.')[0], ob.name, track.name)
            with open(fn, 'w') as f:
                framenum = 0
                while framenum < clip.frame_duration:
                    markerAtFrame = track.markers.find_frame(framenum)
                    if markerAtFrame:
                        coords = markerAtFrame.co.xy
                        if relativeCoords:
                            if printFrameNums:
                                print('{0},{1},{2}'.format(framenum, coords[0], coords[1]), file=f)
                            else:
                                print('{0},{1}'.format(coords[0], coords[1]), file=f)
                        else:
                            if printFrameNums:
                                print('{0},{1},{2}'.format(framenum, coords[0]*width, coords[1]*height), file=f)
                            else:
                                print('{0},{1}'.format(coords[0]*width, coords[1]*height), file=f)

                    framenum += 1
f2.close()

Pay attention to the units used.
The script will output coordinates in pixels, where 0,0 is at the bottom left of the frame.
To use a float values, where the frame has coordinates 0 to 1, change relativeCoords = True
To include the frame number as part of the set, use printFrameNums = True


Walls on cross section of a solidified object look hollow

The only way to do this is by using a boolean modifier (which is non-destructive and reversible, until you apply the modifier, so just don't ever apply the modifier).  The object that you use to drive the boolean can be hidden the whole time, and you can quickly toggle the visibility of the effects of the boolean modifier by clicking the buttons at the top of the modifier; camera button disables visibility in the render, and desktop button disables visibility in viewport.  So you can just always keep the render visibility off, and keep the viewport visibility usually off but quickly toggle it on for those screenshots by just clicking the button and then toggle it back off.  It's not as quick as Alt-B, but it effectively does exactly what you're explaining you want in the question and in your comments.


Extruding along an edge without creating new faces

It was scaling along normals als Mr Zak pointed out


Particles do not appear in object mode but do appear in vertex paint and weight paint modes. Also not possible to render

The reason the particles are not showing up is because the Use Modifier Stack is turned off in the particle system.
If you turn that on now the particles will show up.  You can also get the same effect by dragging the particle system modifier above the decimate modifier.


Fill UV squares completely in all margin

To unwrap the UV, so that every Quad fills the UV space from (0, 0) to (1, 1), select the faces in the 3D View, press U and choose Reset from the unwrap dialog. (The bottom most option.)


Unity flips normal of the some times after Blender export

I found it:
I copied left arm to create right arm and scaled X axis to -1, if I import it like that it works correctly but if I do that and apply scale it flips the normal in unity,  now it works.


Fluid simulation can only last 100 seconds?

It appears this was an arbitrary limit no one knew the reason for. As of this commit the limit is removed (will be in 2.76 or any recent build).


To bring some sort of closure to this question (as it's sure to get asked in the near future again), to get shadows and add a bit more realism, you can refer to the answer on How to make a model cast shadows onto the world texture/background?.

To answer this question with the one thing not mentioned there. You don't really need to use compositing here as you might have thought, the simplest way to do this is to model an object to mimic the shape of the object you want to use to obscure your other object(s) and while some people have and or will use some complex node setups, you can just add a new material to the 'mask object', enable Transparency, set it to Mask and turn the Alpha to 0 like this..

Here is the setup of my scene, the tree trunk has the 'mask' material applied to it and I have a ground plane to catch a little shadow to make it a bit more realistic.. I grabbed the picture of the tree from here.

and here it is rendered..

How to get it to look better is up to you and what you want..


For this you only need select the strip with the Right Mouse Button and press K to make cut where the cursor is positioned.


How is the most bottom bar called and how can i access it

It is called status bar and can be toggled from the Window menu or with the operator

Screen.show_statusbar


Turns out this is actually a bug in 2.90.1 (see https://developer.blender.org/T81112).
It will probably be fixed once 2.90.2 rolls out.


How to override all multiple keyframes at once?

I'm not sure it's what you want but let say you want your object to be rotated on its X axis all along the animation: Open the Graph Editor, lock all the tracks, unlock the track on which you want to make your operation (X Euler Rotation), select all (as everything except the X Euler Rotation is locked it will only select the X Euler Rotation curve) and move it on the Y axis of the Graph Editor (G Y) until it is rotated the way you want it to be.


Note that the decimate modifier is a Modifier, which non-destructively affects the entire mesh (unless a vertex group is defined). From the wiki:

Modifiers are automatic operations that affect an object in a non-destructive way. With modifiers, you can perform many effects automatically that would otherwise be tedious to do manually (such as subdivision surfaces) and without affecting the base topology of your object.

Because of this, a modifier which works in edit mode wouldn't really make sense because edit mode is for editing the base topology.
Note that some modifiers (such as Subsurf) support being viewed in edit mode, however this will not do what you want.
Vertex Groups:
You can however specify a part of the mesh for the modifier to affect by creating a vertex group and assigning that to the modifier.

Create a vertex group by by pressing the + button in Object Data > Vertex Groups

Assign geometry to it by selecting the geometry you want to decimate in edit mode and clicking Assign in Object Data > Vertex Groups:

Pick the vertex group in the modifier:

Sculpting:
Another option is to use Dynamic topology sculpting. This allows you to paint the areas for decimation. See my answer here for more detail.


Exporting to FBX doesn't export texture and animation

Image texures are not critical you can simply copy the files to the exported .fbx and assign them in your target software. In Unity e.g. you would simply drag and drop them to your mesh.

Blender does export animations, make sure that you haved ticked all options in the fbx-export panel:

Put all actions on a single NLA-track, this shows the NLA editor with all actions I wanted to export:

Note that I left a gap between the actions otherwise the last frame overlaps with the first frame of the following actions. Also I avoided inverse kinematics since baking currently seems to have issues. (Can't bake single actions).

Importing in Unity proves that it works:


How can I store the name of selected objects in a text file?

So the answer to this question is not as straight forward as you would expect. Blender is not storing the selection order for objects. It only stores the active object and a sorted list of all other objects. So what you really need is a way to catch all selection events. One way to do that is using a modal operator like this:
import bpy

class OBJECT_OT_record_selection(bpy.types.Operator):
    """Records the selection order while running and when finished with ESC saves it to //order.txt"""
    bl_idname = "object.record_selection"
    bl_label = "Record Selection"

    origSel: None
    selOrder: None

    @classmethod
    def poll(cls, context):
        return context.mode == 'OBJECT'

    def modal(self, context, event):
        # Update selection
        curSel = context.object

        # On selecting new object
        if curSel is not self.origSel:
            self.report({'INFO'}, 'Selection was changed')
            self.origSel = curSel
            self.selOrder.append(context.object)
        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            # Use this to save to an internal text data block
            if "order.txt" not in bpy.data.texts:
                bpy.data.texts.new("order.txt")
            bpy.data.texts["order.txt"].clear()
            bpy.data.texts["order.txt"].write('\n'.join([obj.name for obj in self.selOrder]))

            # Use this for saving to a text file
            #try:
            #    with open(bpy.path.abspath("//order.txt"), 'w+') as f:
            #        for obj in self.selOrder:
            #            f.write("%s\n" % obj.name)
            #    self.report({'INFO'}, 'Saved order to file at ./order.txt')
            #except Exception:
            #    self.report({'ERROR'}, 'Error while writing to file at ./order.txt')
            return {'CANCELLED'}

        return {'PASS_THROUGH'}

    def invoke(self, context, event):
        self.origSel = context.object
        self.selOrder = []
        if context.object is not None:
            self.selOrder.append(context.object)
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def add_object_button(self, context):
    self.layout.operator(
        OBJECT_OT_record_selection.bl_idname,
        text="Record Selection",
        icon='RESTRICT_SELECT_OFF')

def register():
    bpy.utils.register_class(OBJECT_OT_record_selection)
    bpy.types.VIEW3D_MT_select_object.append(add_object_button)

def unregister():
    bpy.utils.unregister_class(OBJECT_OT_record_selection)
    bpy.types.VIEW3D_MT_select_object.remove(add_object_button)

if __name__ == "__main__":
    register()


Realized the answer 5 minutes after posting.

I was trying to mix a texture with a shader.
I needed to mix two materials together.
So I simply added a Principled shader with the logo in its colour input.


The limits for IK solving are stored in the bones properties under Inverse Kinematics.

Pose Mode > Properties Panel > Bone (Tab) > Inverse Kinematics (Section)


In BGE is it possible to leave a boolean function "unapplied"

I'm sure the boolean modifier is not supported in the BGE (2.79).


I wasn't able to find a way to perfectly align the peices with a snap of sort like I had hoped. That said, I was able to find a method that allowed me to align them to a degree of precision that makes it so that even the part that should be the furthest away is aligned to match exactly to within a millionth of a unit.

Snap one vertex

Enter Edit mode on the object to be moved (Select it and press Tab)
Select one vertex
Move the 3D cursor to that spot (Shift + S, Cursor to Active)
Exit Edit mode (Press Tab)
Set the origin to that point (Shift + Control +
Alt + S, Origin to 3D Cursor)
Turn on Snap During Transform (Shift + Tab)
Set its Type Of Element To Snap To to Vertex (In the header, next to the magnet icon)
Set its Part To Snap Onto (just to the right of the Type Of Element To Snap To) to Active
Move it until it snaps (G key to move, move your mouse to the vertex that should align)
Rotate it most of the way
In this case, I knew that it was already knew it was aligned on one axis, so I rotated it along that axis (in this case the Z axis). Because the origin is now at the perfectly aligned vertex, it won't move if you set the Pivot Center to work by its origin (On the header, to the right of the mode option and the display method, set to Active Element)
I rotated along the Z axis (R to start rotating,Z` to then constrain to the Z axis). I got it decently close.
Fine tune
I then zoomed in as close as I could get to the point that would be the furthest away (opposite side of the circle of vertexes) and started editing the object rotation while in Object mode and wireframe view mode (Z while in Object mode). You can find this in the Object section of the Properties window. I just edited the Z rotation little by little until it matched as closely as I could get. After checking, there is zero difference in the position of the vertexes now.


Is there a tool in blender that is similar to the 'blend' tool in Illustrator?

Sometimes is better to ask "How to create ...", because in your case there are a bunch of ways to get desired result, eg. to get a lot of pages you can try a Cloth Simulation.

Cloth Simulation

Add Plane, switch into Edit Mode move along X to side, add few Loops (Ctrl+R) along longer side
Add an Empty
Select Plane add Array Modifier > Relative Offset > 0, Object Offset > Empty and rotate the Empty in Y axis
Apply the modifier
In Edit Mode select the first and the last page as well as all central vertices of all pages and add them to a Vertex Group
Add Cloth Simulation, use the newly created vertex group for Pinning, enable Self Collision, adjust parameters as you like


Blender

Blender particles are not supported by the BGE. Due to the complexity and inefficiency they will not be supported in the near future (at least not in a way that they can be useful in a game).

BGE Particles

Particles in the BGE are ordinary objects. They are nothing special. All you do is you dynamically create a lot of them.

A simple way is to use the Object Actuator in Add Object mode. When activated the actuator will add a copy of the referred object.

To get flames, sparks and smoke you add different objects. Each object can animate over time (position, location, material). This all together can create the illusion of fire.

Due to the complexity of that topic I do not want to go into much detail here.

I suggest to search for BGE fire tutorials. There should be plenty out there.

Pre-rendered textures

An alternative / additional way is to use textures with pre-rendered and animated flames.


Is it possible to use the Extrude or Spin tool to get something to rotationally extrude along a curved path?

I am not sure I understand what you mean, is this the shape you wish to achieve?

The way I see it you can do it in several distinct ways

Either extrude your whole shape at once and bevel the outer edges of the result afterwards. You can use a mirror modifier in two axis so you only have to model half of it.
Draw the quarter circle shape section as a mesh and extrude it up step by step along those selected edges. You may use snapping to guide your shape all the way up, or
Draw both your section (semi circle) and the path (curved shape) of the bow as a bezier curve, use the section as a bevel object on the bow shape bezier curve. Use the curve radius on a per vertex basis to control the thickness of the bow along the path. (Option I used in the image above and bellow)


Smoke resolution is based on the size of the domain. Ergo, a large domain with a smoke resolution of 75 will have smoke that appears far more chunky than a small domain with a resolution of 75.

One option is just to change your smoke resolution.
Another is to enable an adaptive domain and crank up the "Additional" value. This will increase the size of your domain while keeping the resolution intact.


VSE: Fade to white via a bloom transition

You can multiply the glow effect by using the Multiply value in the property panel.
You can animate the value from 1 to 20

You can change the multiply value both on the glow strip and the video clip to combine the effects and to get a complete white image


Why does the shadow pass not account for mesh lights?

That is simply how the shadow pass works. According to the wiki, the shadow pass is only affected by lamp objects, not mesh objects.

I mad a little experiment and was quite surprised, but It may shed some light on this. I also edited my previous speculation since I was wrong (check revision history).

I rendered a little scene with both an area light and a light emitting plane. It was the default cube sitting on a plane and on the opposite side from the light source was another plane with a glossy shader (roughness 0).

This is the render with the area light.

This is the render with the mesh light.

The one with the area light have no caustics! This simplifies things a great deal when it comes to calculating shadows. Also, mesh light can be any shape while area light can only be square and rectangular. I'm guessing that devs made a choice. Mesh lights would be to complicated or expensive to calculate shadows for since they behave more complex. Area lights are simpler (only rectangles and no caustics) so calculating shadows are easier and/or cheaper.


'Object does not have geometry data' error when running headless?

Quoting from https://docs.blender.org/api/242PythonDoc/API_related-module.html :
Background mode examples:
# Open Blender in background mode with file 'myfile.blend'
# and run the script 'script.py':

blender -b myfile.blend -P script.py

# Note: a .blend file is always required.  'script.py' can be a file
# in the file system or a Blender Text stored in 'myfile.blend'.

I have tested it but you can try adding a file in your command line options


Blender 2.8 Scripting for a simple button

Pre or Append to the header.

With all panels and headers in blender you can append or prepend a draw method to them.

Test script prepends a splash screen button to topbar

import bpy

def draw(self, context):
    self.layout.operator("wm.splash")

bpy.types.TOPBAR_HT_upper_bar.prepend(draw)

To find the class to "leach" onto, with developer extras on, right click and view source. With the naming convention, TOPBAR pretty self explanatory, HT it's a header type. Hence using autocomplete in python console is a way to find contenders


Not possible to ADD SCENE at all - Video Editor

First of all, make different scenes, each one with their animation.
Then make a new scene without any animation and open the Video Editing tab.
Finally, from the Video Editing tab, try to add a scene either by Shift+A with the mouse hovering on the Video Sequencer panel, or as you did, by clicking on the Add>Scene dropdown menu.
You should be able to find all scenes but the new one you're video editing from!


Can you use a face to slice other faces?

There are two methods that are standing out to me.

One is the boolean modifier. For this, you need to make the crystalline structures a separate object. Than add a boolean modifier to one of the objects and use the union type. This will actually join the objects, the downsides are that it can create sloppy topology so it really depends on how willing you are to have n-gons and triangles in your mesh.

The other one is the intersect tool which is new with 2.72. For this you need to be in edit mode and have everything selected. The easiest way to find it is to use the spacebar search menu. Just search "intersect".

Here's a demo on the intersect tool:
link

This won't join the two meshes like the boolean modifier, but instead it puts the verts where they need to be and leaves the user up to deciding what to do with the mesh.

I hope this helps.


How to share my 3d model made using blender?

Upload the model to sketchfab. The model can then be viewed and rotated as a 3d object with no special software, on a web browser.


How to render Wireframe for the entire scene not just one object?

Here how would I do this task.

Get 2.8x version
Set up overlays like this:

When setup matcap and cavity as you want:

If the result is not bad, click View -> Viewport render.
If you want wireframe on top of Cycles (or outer) Render Setup viewport like this:

In color management set View transform to default

When  click View -> Viewport render and compose resulted image over render using multiply.


I've found the solution :

download the Ogre Command-line Tools
create a new folder in your root directory named OgreCommandLineTools ( C:\ for me )*
copy paste what you have downloaded from Ogre command-line Tools in the previous folder

now when you export your 3d model with blender2Org you will find the .mesh file


How to generate Perlin Noise for materials

You have set the Type to "Hard", if you set it back to the default "Soft" you will see it's the regular Noise Texture, compare it to this article Wikipedia: Perlin noise.
If you want to achieve a look like "Hard" you have to tweak the distribution with a Color Ramp, here's a simple try on it:


First, you need to fix the normals on the hat.  They're pointing the wrong direction.  This can often cause issues with physics, which can use normals to decide inside/outside-- what's solid and what's not.
But that's not the only issue.  The other issue is that you're colliding simple, low-vert-density strings of verts-- remember, your skin modifier isn't even being evaluated until after the physics-- and so there are only a few places on the mesh that are even being checked for collision with the hat.
By default, soft body physics like you're using uses virtual balls centered on each vertex of the mesh to test for collision.  And if you play that animation, after fixing normals, you'll notice that none of your vertices ever go through your hat.  The collision is working!  It's just that it looks wrong, because even though the verts collide properly, the edges still go through the hat.
One thing you can do is, just make more verts.  This will create more places along your string for Blender to test for collision with the hat.  Subdivide your strings to create 3 or 4 times as many verts.  Do this in edit mode: modifiers won't be evaluated until after your soft body physics have run.  You'll probably have to tweak your physics settings afterwards: more verts means more freedom of motion, which usually needs to be compensated for by strengthening soft body edge forces.
Another option is to use edge collision instead of vertex collision.  In properties/physics/soft body/edges, you'll see a checkmark for "collision edge".  If you enable this, Blender will try to use the edges of the mesh for collision.  I think you'll see that you'll still want more vertices than you have right now though.


To move it's location:
Select the object, move the 3D Cursor to the center (Shift + S, R) or to a desired location, then move the selection to the cursor (Shift + S, T).

To change the origin:
Select a part of the object in Edit Mode, move the 3D cursor to it, and then
switch to edit mode and snap the object to the cursor(Shift + Ctrl + Alt+ C, T).

Rotate the object first if you want to change the angle.


Landing Gear Rigging Constraints using empties

Method IK bones

Create an armature and create a bone for each object in the rig and put it in the right location. One bone for the Cylinder, one for the Piston, one for the Cylinder Arm (arm connected to the Cylinder), and one for the Piston Arm (arm connected to the Piston).
Select the armature and go into Edit mode, and go to Properties > Bone Properties > Relations. Make both the Cylinder Arm Bone and the Piston Bone children of the Cylinder Bone. But uncheck the box Connected before doing so.
Make the Piston Arm Bone a child of the Cylinder Arm Bone. In this case the Piston Arm Bone should be connected to its parent, so for this bone the box Connected should be checked.
Parent each object to the corresponding bone. In Object Mode select an object, shift select the Armature, go to Pose Mode, select the bone, press Ctrl + P and choose Bone. Repeat for each object-bone pair.

Go into Pose Mode, select the Piston Arm Bone and add an Inverse kinematics constraint. As a Target choose the Armature. Set the Chain Length to 2. As the Bone choose the Cylinder Bone. Now the Piston Arm Bone should snap to the Cylinder Bone (So the starting angle of the arm bones does not matter. But it does matter where you position the Cylinder Bone; its base should be where you want the end of the Piston Arm Bone to rotate around).

You're done. In Pose Mode, move the Piston Bone along the Z-axis to move the Piston and the arms. Rotate the Cylinder Bone around the Z-axis to rotate the whole rig around the Z-axis.

Method Damped Track (does not allow for rotation around the Z axis)
It can also be done by using Constraints. However it does not allow for rotation around the Z axis, but I didn't realize that at first. I'll keep this part of the (initial) answer, just in case. : )
It is best before you active a Damped Track constraint (note the eye icon and how it is inactive), that the object that has the constraint is aligned with one of the main three dimensional axis.

It is also wise not to use the object you want to be the Damped Track target, but to use an Empty object parented to the intended target object and use that empty as the actual target instead. This can help focus the Damped Track at the right point, but will also limit unexpected and unwanted behavior due to the Damped Track recalculating positions.

However, with this simple setup there is limited control of the position of the joint where the arms meet. But it might suffice for small movements.


Blender not responding while running my script

Short answer: No
See: Strange errors using ‘threading’ module

Python scripts run 'blocking', Blender will wait until finsihed. It isn't thread-safe to run python in parallel. You may be able to get around the issues with Blender crashing with python running own threads using a modal operator with timer: Blender UI Multithreading Progressbar. Also consider if a modal operator running the background is suitable for your use case (let it return {'PASS_THROUGH'}).

If your scripts run for hours, you should also investigate why they are so slow. See here what hurts performance: Python performance with Blender operators


There's an addon written by Jonathan Stroem to allow saving the backup blend files into a subfolder. I'm sure you could easily modify it to write the file somewhere else on your system.

Config blender to save backup files in subfolder


How to ignore backfaces when doing a raycast?

Did it. I did not even bother if front or backface was hit because the first hit is always backface, so i just added a small offset to the hit vector (depending on view vector) and used it as new origin for a second raycast.

ray_origin_offset = mathutils.Vector((0, 0, 0))
if view_vector[0] < 0:
    ray_origin_offset[0] = -0.0001
else:
    ray_origin_offset[0] = +0.0001
if view_vector[1] < 0:
    ray_origin_offset[1] = -0.0001
else:
    ray_origin_offset[1] = +0.0001
if view_vector[2] < 0:
    ray_origin_offset[2] = -0.0001
else:
    ray_origin_offset[2] = +0.0001
ray_origin = hit + ray_origin_offset
ray_target = ray_origin + view_vector
hit, normal, face_index = obj_ray_cast(obj, matrix)


For .mp4 output you need to select the MPEG-4 container. The output quality can be changed by setting the "Ouput Quality".


Adding current scene to VSE (Blender 2.8)

You can't add the current scene. Just Add a new Scene to the file and use the VSE from there now you can add the other Scene.


Tesla C1060 not seen by Blender after install

Your card is not supported. It has a CUDA compute capability 1.3. Support for cards with compute capability less than 2.0 was dropped a few versions ago.
Quoting from the Blender manual:

CUDA
Nvidia CUDA is supported for GPU rendering with Nvidia graphics cards. We support graphics cards starting from GTX 4xx (computing capability 2.0).


Light is hard to calculate. Cycles is a path tracer, which means it shoots out light rays from the camera, bounces them around the scene and looks where they end up.

How many light rays are bounced is controlled by the "Samples" setting.

The issue that you're facing is that you've got a lot of light sources behind (I presume) glass panes, with a lot of geometry for the light to bounce around in. This is coupled with a very low sample count, and is the reasn for your noise.

Increasing the samples, leaving the lights turned off or decreasing light bounces might all be solutions to the issue you're facing at the moment.

If you find yourself sitting at 1000 samples or above with a lot of noise left then I'd recomment getting enabling the denoise in the scene settings. Be aware, this washes out colors and works against surface detail. Use it with caution!


How to bake materials [With complex node setup] into Texture in blender 2.9?

The edges of your snow object are very large n-gons:

The vertices of the n-gons do seem to be coplanar, and the normals appear to be facing the right direction, so I’m not entirely sure why this causes any trouble. But empirically, they do seem to be the source of the issue—if I remove them, the problem goes away:

If you need the edge faces, an easy way to recreate them is to select the outermost edge loop, then extrude downwards along the Z axis:

To make the lowermost vertices coplanar, you can then press SZ0⏎ to scale to zero along the Z axis:

Now you can re-unwrap the mesh, and for baking, I recommend using UV ▸ Lightmap Pack, since that will fill the space as optimally as possible. Then re-bake:

(Note that I’ve used a small sample size here for a short baking time, which is why the result looks so noisy, but obviously you should bake at your normal resolution to get better results.)


Some materials aren't rendered in the Blender Game Engine

I am having the same problem. Best solution I could find (more like a workarround) is to apply all the modifiers of the object which is causing trouble (in our case, it is Luftauslassheck).

Should you find out what is happening, please let me know. Here is a link to my blend if you want to take a look at it. The object is Support.Cover, which only has the material PlasticMaterial.002, used in other objects as well.

Nice car model by the way


With your download in the root there is a README.md this contains install instructions:

"### Blender Addon:
Zip the coa_folder.
Go to File -> User Preferences -> Add-ons and click the “Install from file...” button.
This will install and enable the Addon for Blender. Don’t forget to save the user preferences, otherwise the addon will not be activated after restart."

as it says go inside the blender folder and zip the coa_tools folder.

then install from file and select that zip folder.


Limit Location Constraint on Armature Breaks in a Loop Animation

After a few days I have managed to fix it. If anyone comes across the same issue I believe my answer should help.
Again following the tutorial by Max Berends at https://www.youtube.com/watch?v=t1GmLAVeySY
You must have your tracking empty exactly on the pivot point between the lower pump section and the connecting arm.
I recommend using:

Object>SetOrigin>OrigintoGeometry/(Shift+S) to set the origin to the mesh.
At your new origin point, create the new empty.
Once you have an armature from the top point of the arm, go into edit mode for the armature, select the second point and go to Object>SetOrigin>SelectedtoOrigin

I think the discrepancies in location can slowly throw out the animation in this case because of the "TrackTo" constraint, as seen in the video in my question post. Having the empty in the exact location has fixed it.
Hope this can help someone.


Is there any way to save background images in the .blend file?

The most convenient way

  File -> External Data -> Pack into .blend

In the report area it will say 'n files packed' Where n is the amount of images currently in the image list. Now hitting save will include those images in the .blend.
The problem you might have with this method is that it will auto-pack any subsequent images you add.

Alternatively (one by one, gives more control)
You do them individually, go to the UV image editor. For each image you want to pack you select the image so it shows in the view, then

  Image > Pack Image

Again you have to save the .blend file before exiting.

Further reading
Obligitory Blender Wiki link: Pack and Unpack Data, it's an interesting read.


It's already passed 11 months, and what I understand for 11 months is boolean messing up topology and should be avoided as possible.

However sometimes it's really helpful to create really complicated geometry, and there are some ways to fix the messed geometry.

One way I worked was fill triangulated faces instead of NGON face, which NGON means the face that has 5 or more vertices, works fine in my case.

If the shape you want to create is possible to make without boolean, it's better to not using it, however if you really needed it, do carefully while treating the NGON faces that generated after boolean operation.


Character wiping fog off a mirror using dynamic paint

So using a LOG math node at 0.9 with a colour ramp into the factor did the trick. If anyone knows exactly why I'd love to know.


It's completely unimportant, until you hit some limitation. Once you do, you know where it'll hurt, and possibly how to solve it.

A high-poly model can be used to bake bump maps, shadow maps, etc. which can be used to give a low-poly model a high-poly look. So even though you may not use the high-poly version in the end, it still is useful.


Cloth Stimulation Not Working (Blender Not Responding)

The problem is that your model is very small. I think that a severe collision has already occurred at the start frame, making it difficult for the calculation to converge. When I increased the size of the model by 10 times, the simulation became much faster.


2.81 "Alpha" drop down menu in Scene>Film tab missing?

I played around with some of the settings i used, it looks like the Volume scatter in the shading tab was the problem i removed it and it works now


Light an object with an inner light and volumetric world

I'm not using a volumetric world here, so in essence this doesn't answer your specific question, but it does make the light rays coming out of the die visible, while preventing the volumetrics from affecting any other objects. I hope it does solve your problem.
I won't go into modelling the die, because I assume from your question that you already figured that out. However, once you've placed your holes, don't delete the faces. Instead make sure the faces of all the holes are selected, then press AltE to bring up the Extrude options followed by V to extrude along vertex normals. Then drag your mouse or type in how far you want to extrude, confirm with Enter or LMB, and hit CtrlNumpad+ once to expand the selection, to get something like this.

Create two materials, and assign one of them to the now selected faces. This will be the volumetric material. Here's the node setup.

The Position socket of the Geometry node gives the coordinates of the shading point.
The mapping node here really does nothing, but I included it for completeness. Use its location values if the die is not located at the world origin (0,0,0) and its scale values if you want the falloff to be different along the X, Y and Z axes.
The Separate XYZ separates the location vector into three values.
The following math nodes upto and including the last Power node, calculates the distance from the centre of the die, by use of the The Distance Formula in 3 Dimensions.
The Divide node set the outher threshold. Enable Clamp on this one.
The ColorRamp lets you finetune the falloff. Make sure you flip it, by clicking the double arrow, to get the black at the right end and white at the left end. By adding more control points in the ramp and changing each point and/or changing from linear to something else, you can get very precise control over the falloff.
The Multiply node following the ramp sets the maximum density. I've input it into a Volume Scatter, but you can use Volume Absorption or emission, or any combination of two of them or even all three, by use of Mix and/or Add shaders.

Here is the result.

I've used a cube and square holes. The cube is placed at the world origin, where there is also a point lamp with default settings. Environment light is turned off, and the external light comes from a sun lamp.


How can I manually calculate bpy.types.PoseBone.matrix using Blender's Python API?

armature.data.bones["Bone"].matrix_local

Is the bone's world un-posed matrix (the pose_bone.matrix in rest state).

 armature.pose.bones["Bone"].matrix_basis

Is the bone's local pose matrix.

From there we can calculate any bone's world matrix by recursively traversing it's parents. Note: This will not include any constraints or IK (but it will include drivers or actions):

def matrix_world(armature_ob, bone_name):
    local = armature_ob.data.bones[bone_name].matrix_local
    basis = armature_ob.pose.bones[bone_name].matrix_basis

    parent = armature_ob.pose.bones[bone_name].parent
    if parent == None:
        return  local * basis
    else:
        parent_local = armature_ob.data.bones[parent.name].matrix_local
        return matrix_world(armature_ob, parent.name) * (parent_local.inverted() * local) * basis

You can test it on an empty and some armature with some active pose_bone. Also the armature_object's transformation is accounted here:

import bpy

empty_ob = bpy.data.objects["Empty"]
armature_ob = bpy.data.objects["Armature"]

bone_name = bpy.context.active_pose_bone.name
empty_ob.matrix_world = armature_ob.matrix_world * matrix_world(armature_ob, bone_name )


I am sure if you asked google on this you would find fitting Materials. But you seamingly didn't and neither did I. So I made the following setup to be as parametric as possible, since you didn't make clear what you want to achieve.

There are those named fields that you can use to tweak the distortion and there is the color selector on the left on which you can specify the direction of the lines. You can also replace that color selector by a Combine XYZ Node to gain better access to the numbers of the normal vector. Hope this solution can satisfy your needs.

EDIT:
If you want to make the texture that you showed in your post, you just need to turn the distortion of the noise texture up. I pretty much got it to match your image.


How can I achieve a "painted" effect in my scene in blender?

The filters in Photoshop are your best bet. Gimp or Krita which are both free might also have such effects, but looking at the Blender compositon nodes i couldn't find any solutions. One thing that can be done in Blender are the lines using Freestyle. This will have the edges of all models show up and there are many advanced features regarding to this.


How to apply sculpting to mirrored object

In Edit mode go into the header menu > Mesh > Symmetrize, then choose the symmetry axis in the Operator box.


Sorry for noob question
Problem solved, I have made something definitely wrong :)


I have found a solution to this. So I had to use two different materials for both the yellow top and the silver part of the logo. I heared that this issue is caused by too dense geometry there.


How can i modify a Displacement texture roughness?

Displacement expects a number, not a color. You can see that because the displacement's input is grey whereas a color-value is marked as yellow in the Node Tree.

So you normally convert the color to a value via a RBG to BW Node. You then can use Math nodes to freely manipulate the value until it fits your needs. In your case I would use a Multiply and then play with the factor a bit until satisfied.

I've used a Voronoi Texture as a stand-in for whatever texture you want to use, so you can just swap that out.

Note: I've heard that this conversion is done automatically when you connect a color-output to an value-input. Apparently this won't lead to any problems, so you can leave out the RGB to BW node and just connect the color output to the Math input (thanks @TARDIS Maker).


how to join multiple rigged mesh and bones

Figured it out.

select bone and mesh and duplicate them.
select individual bones of the duplicate and rename them so they have unique bone names from the original. Renaming the bones will automatically rename weight painted the vertex groups.
apply location rotation and scale to the bones in object mode, and make sure all armatures have the same origin
select the mesh and hit ctrl J
select bones in the same order as you selected the meshs and hit ctrl J


shrinkwrap ("decal") around entire object?

It is completely unclear to me what you are trying to accomplish, or why you want to use the tools proposed in the question. So I'll post an answer as blindly as trying to break a piñata:

(photo: AlejandroLinaresGarcia, Wikipedia)

If you want a cube with a texture, use the texture directly on the cube using UV coordinates:

If you need the cube to have different front and back, the images mapped have to correspond with those views:

To have some geometry converted to the shape of another, then you'd use the shrinkwrap modifier. Have the brain object be larger than the cube, the you can shrinkrwrap it around the cube using nearest surface point:

Brain model by mahesh downloaded from  http://www.blendswap.com (login required)


After having converted the grease pencil strokes to a mesh I can't add any texture in texture paint mode

I don't think you can directly paint onto the GPencil object that you are converting to mesh. I include a picture here of converting GP to bezier and then to mesh once closed.

Texture paint mode is only available for Mesh objects, so that is why the option doesn't appear.


Blender Loop cuts and vertices measurement

Blender doesn't offer exact dimension modelling tools that you may expect in a CAD program. There are some things that may help, start with this previous question.

Most tools allow you to type in numeric values while they are being applied, what that value represents may vary between tools. When using the loop cut tool you can enter a value between 1.0 and -1.0 that represents a percentage of movement towards the next vertex on either side with 0.0 being centred.

Extruding allows you to enter a length that is a distance from the original location. You can also cancel the extrude to leave the new vertices in the same location as the original vertices, then move the vertices (G) which allows you to enter x,y,z values as distance moved in each direction. The first number you enter is used for x then you can use tab to move to the y and z values.

Pressing Ctrl and Shift can also help - while you are moving vertices pressing Ctrl is a shortcut to enable snapping which by default will snap values to whole units (grid increment snapping type). Pressing Shift will slow down the movement to allow more precise placement. Pressing Ctrl and Shift will snap to 0.1 increments.

With loop cut Ctrl will snap to 0.1 increments, Shift will slow down movement and together will snap to 0.01 increments.


Camera following a circular path around object stops after 1 rotation, I want to have it loop over and over

There are options in the Graph Editor tab : Channels > Extrapolation Mode > Make Cyclic or Shift + E and Make Cyclic from Graph Editor, that will put your animation in a loop.


How to Import a model with textures applied?

You would need to enable the 3DS Import/Export Addon in the User Preferences (Menu: File / User Preferences)

Then Import the .3ds file (Menu: File / Import 3D Studio (.3ds)
some of the UVMaps don't match the textures you would need to reassign them.

Enable Transparency in the Material Settings for glas parts:

You would also need a few lamps in your scene, in Object Mode ALamp/Hemi and place them e.g. in front of the model, then you will also see the textures.


Grease Pencil-Preceding frame visible in next frame(non onion skin)-turn off please

This is defacto standard in 2D-animation. This behavior makes easy to draw on twos, threes, ets. without adding additional keyframes. (When you draw every second frame it is called "drawing on twos", every third - "drawing on threes" and so on.) Timeline looks clear and ones, twos and threes easy to recognize and manipulate with them.

Know more why using twos is important in 9th Principle of Animation


Making a Trypophobia-triggering image In Blender

Tissue addon

Another possibilty would be to use the Tissue add-on.
You basically define a "component", in this case a little hole with a protruberance (the one outlined in orange) and spread it on the faces of a base mesh (suzanne, outllined in light orange).

Run the Tessellate option with the objects selected in this order, enable the merging option and then run the subsurf modifier on the result to smooth the "component".

The cool thing is that you can use whatever shape as input component.


You can convert Object coordinates into Polar coordinates using the 'arctangent' trigonometric function by using :

arctangent(y/x)

This will produce a result in Radians (where there are pi radians in 360 degrees) although without additional nodes it will only produce results for half the rotation (and will produce negative values).

The following nodes should produce a result that varies from 0.0 to 1.0 :

To explain this a bit, the Object coordinates are split into the separate X, Y, Z components and the Divide node used to generate Y / X. This is passed to the Arctangent node which produces the angle (in radians) between -pi/2 and pi/2 for half a rotation (for the second half it repeats -pi/2 to pi/2). This is divided by 2*pi to convert it to the range -0.25 to 0.25 and 0.25 added to shift the range to 0.0 to 0.5. The Less Than node is then used to detect the second half of the rotation and add 0.5, resulting in the full rotation mapping from 0.0 to 1.0 producing the result shown in the image above.

Blend file included

The other half of the polar coordinates is the distance from the origin. This is simple to achieve as sqrt(x^2 + y^2) as follows :

Combining these into a nodegroup to allow it to be easily reused results in the following :

Using the nodegroup to build a procedural eye texture can produce the following :

Blend file included


How to receive correct file and directory paths from user?

I found the solution here. use bpy.path.abspath(path) to get the absolute path to the file or directory.


Apply different materials to boolean cuts

Nevermind, I've found a way to do it, you have to add two materials to the base mesh for it to work, once you've added them it's just playing with them to match the mesh with the materials


Blender and Unity. Materials/Shaders question (Cycles, BlenderRender, Does it matter??)

Check out Poliigon for amazing textures if you don't want to tinker the settings manually.

In Blender, we mostly use Cycles Render engine and starting 2.80, the internal render engine(Blender Render) has been removed.

In order to tinker with the material settings, you need to make sure the render engine is set to Cycles render and select Node editor from the bottom left corner(change from 3d view to Node editor or extend a new tab and change it).

It works similar to how 3d View works, shift + a to add a new shader,x to delete, g to move etc..


Import .obj with texture, where texture is more photos

Make sure image search is checked. It may have material id's and if you could import as an .fbx you would probably get your textures. But, you can solve this manually yourself by using ctrl+shift+t with user interface keymap settings inside the shader editor to automatically have cycles setup anything other than gloss maps and ao maps without you having to do anything else. It does not take long.


How would I make an indented swirl around this sphere

A way to do it is to start with a UV sphere which has a lot of rings. For instance, 360 rings or 720 depending on the amount of turns you want to give to the swirl. Keep segments as default (32 or so).

Having these many rings allows to proportionally rotate around Z the summit of the egg for n times 360 degrees.
Here set proportional editing on, set the fallog to linear, and use RZ360. Make sure the proportional editing sphere reaches the bottom of the egg. Repeat it for each turn you want to give.

Now select an edge loop joining the top and the bottom. Set proportional editing to smooth, and S to scale shiftZ to scale only on X Y and lower the proportional editing sphere so that it influences few vertices around the selected edge loop.

Can also animate the twist... using a simple deform modifier:

In that case, same principle but rotate nothing first just make the indent.
Then add the simple deform modifier and animate the angle:


With no further information there could be two main reasons:

If the object is visible in the Viewport, but invisible in the rendered image, you've set Disable in Renders for the object.
If it's already invisible in 3D Viewport when you set the mode Viewport > Rendered (as your question sounds like), you probably disabled Camera Visibility under Properties > Object > Cycles Settings > Ray Visibility


Modelling technique, how is this workbench created

It's a linked dupligroup.

Dupligroup

A Dupligroup means that the plane (it could as well be an Empty) generate a group instance at his position. You can verify that in Object/Duplication. It allows to manipulate easily the whole desk, despite it is composed of several different objects ; and it's memory efficient (in Blender's mind, there is only ONE desk).

Link (linked library)

In the outliner, you can see the list of the different groups available, by selecting "Groups" instead of "All Scenes". As you may notice, the "file with an arrow" next to the name of the group indicate it is a Link : it refers to a group that is in another file (in assets/desks.blend).

You can open desks.blend, and try modifiy something on the desk (ie, change one of the materials). Save desks.blend, then open (or re-open) classroom.blend : all the desks have been modified.

Why?

There is many advantages in this workflow. It allow easy reuse of assets, it's flexible, it allow one artist to work on the assets and an other on the scene...

It's also efficient because the group is loaded in memory only one time. And the size of each blend file is kept small, this is easier to work with many small files than with a big one.

How?

In myAsset.blend, create your asset as you would usually, with different objects, modifiers, etc. Once finished, select all your objects and press Crtl+G to add them to a new group. Give the group a meaningful name (in the outliner, or in Object/Group). Put your asset at the center of the scene (0,0,0) because that will be his Origin.

In myScene.blend, click File/Link, navigate to myAsset.blend/Groups/myGroup. Now you have an instance of the group in your scene, you can manipulate it like any object. To add another instance, just press Shift+A /Group Instance/myGroup.


What does the stamp drop down menu in the render panel do?

The Stamp section in the Render panel goal is used to draw some information on the render output. This can be useful for a work in progress production.

See the blender wiki.

For example you can select Frame to print the current frame number on the final output.

The Font size, Text color and Background settings allow you to control how this information is displayed.

You can additionally print a custom note by checking the Note setting and writing whatever you want.


The Bevel Tool won't work, because of too tight topology.
And without Clamp Overlap you'll get ugly artifacts.
You need to keep enough space for the beveled edges, use n-gons if necessary.


General hardware age isn't the big problem here, and that's what the other commenters were talking about. Their advice is great if you have an x86 system of that vintage (ex, Pentium 4), but you don't. You have a PowerPC machine. That's problematic as the official OS X Blender builds are not compiled for PPC and haven't been for quite some time. Since 2.63, to be exact. You can find it here: http://download.blender.org/release/Blender2.63/

Download the file blender-2.63a-release-OSX_10.5_ppc.zip and install as usual. It should be your best bet.


How do I shrinkwrap an object to a curved surface cleanly and efficiently?

First you need to put Shrinkwrap modifier on the top of the modifiers stack.
Then in Shrinkwrap modifier change Mode to Project and in Direction enable Positive.
Then align the eye mesh tangentially to the surface of the sphere.


Welcome to the wonderful world of math!

(note that the top face gets a little screwed up if it's perfectly flat, but that's easy to fix just by adding or subtracting a small value before the Modulo math node)

Modulo is a math operation available in the Math node. It gives the remainder when dividing two numbers (e.g: 5 mod 2 = 1, 9 mod 3 = 0, or 2.3 mod 1.0 = 0.3).

In this case, we divide the coordinates (which range from 0.0 to 10.0, since the mapping scale is on 10) by 1.0, and thus for every whole number the math node shows black (remainder is 0.0), but as the decimal increases it'll get lighter (bigger and bigger remainders) until we reach the next whole number and it turns black again, restarting the cycle.

Since a gradient texture only changes on one axis, we only need to do the modulo operation on the X axis, but in other cases you may want to do it for the Y and Z axes as well.


The Clipping Region works only in Wireframe ans Solid shading modes.

Shortcut Alt+B for toggle


Make a fan rotate constantly throughout the game in BGE

I suggest you turn the fan axis via a motion actuator:


BGE : Stop Animation at an arbitrary point and return to frame 1

Yes. You can do this with logic bricks. You can actually do quite a bit with logic bricks. (I've made entire games only using logic just to prove it is possible to do so)
You'll need to start with two properties, a Boolean to control when the animation is playing, and an Integer property to control what frame the animation will display.
You'll need an always sensor (with true level triggering enabled) connected to an action actuator set to property - this will make the selected action display the frame of that action that correlates to the property that is set in the actuator.
You'll need your boss object's near sensors detecting the player, and assigning the Boolean property true or false.
Then, when the Boolean property is true, it will rapidly add 1 to the integer property controlling the animation's display frame, making the animation play. The moment the Boolean property turns false, it will assign the animation's frame to 1, resetting your boss object's attack.
You'll also want a property sensor waiting till the animation is done playing, to allow looping. to do this, set the value in that property sensor to however many frames is in your animation. When testing, I used a 40 frame animation, so I put 40 in that field. This property sensor can connect to the same actuator as before that assigned the frame number to 1, as it has the same function (resetting the animation.)
Or, if you do better with pictures:


Pawel,

Not really an answer

even though the code below looks like a significant rewrite, it's mostly just for generic OS use...
What I had noticed running through the script below (which is likely causing the sync & updating issues you're referring to) is that the renders are generated based on the segmented window throughout the entire animation sequence, then moving to the next segmented window and running through the entire animation sequence again.
As such any interpolation of animation & raytracing, etc will be recalculated not only frame by frame, but each segment frame by frame.

If you watch the console while running this you should see what I mean.

    """
This script:
Verifies, the active blend file is saved
Generates a folder for the active blend file where it is saved
Generates sub folders for each scene
Renders for each scene
All naming is based on names used in blend file (blend file name, scene names, object names)
For different render options change the true/false option at ~line 52 & blender menu options
"""
"""
http://blender.stackexchange.com/questions/47530/rendering-multiple-borders-by-a-script
"""

import bpy
import os

filepath = bpy.data.filepath
osdir = os.path.dirname(filepath)
osfile = os.path.basename(filepath.replace('.blend', ''))

selected = bpy.context.selected_objects

list_of_all_scenes = bpy.data.scenes
scene = bpy.context.scene

n = 8
m = 8

if bpy.data.is_saved:
    for scn in list_of_all_scenes:
        bpy.context.screen.scene = scn
        if not os.path.isdir(os.path.join(osdir, osfile, scn.name)):
            os.makedirs(os.path.join(osdir, osfile, scn.name))
    for scn in list_of_all_scenes:
        bpy.context.screen.scene = scn
        cnt = 0
        scn.render.tile_x = 16
        scn.render.tile_y = 16
        scn.render.resolution_x = 800
        scn.render.resolution_y = 600
        scn.render.resolution_percentage = 100
        scn.render.use_border = True
        scn.render.use_crop_to_border = True
        for i in [x * 1.0/n for x in range(n)]:
            for j in [x * 1.0/m for x in range(m)]:
                scn.render.border_max_x = i + 1.0/n
                scn.render.border_min_x = i
                scn.render.border_min_y = j
                scn.render.border_max_y = j + 1.0/m
                cnt += 1
                bpy.context.screen.scene.render.filepath = os.path.join(osdir, osfile, scn.name, scn.name + "_cnt(" + str(cnt) + ")_frame(" + str(scn.frame_current) + ")_auto")
                bpy.ops.render.render(animation=False, write_still=True, use_viewport=False, layer="", scene="" )


I don't know any other reason, except you have no camera in your scene.

You can add a camera by: Shift + A  > Camera.

Or maybe you have a camera in you scene, but it is switched off for render. Check the little camera icon on right side in Outliner.

There are Eye for visible in viewport, arrow to prevent selection, and a Camera to toggle visibility in render.


How can i join vertex of the same bezier?

You can only make a cyclic curve, there is no way to join it multiple times as far as I know.


In my experience, it is best to get the model as "right" as possible as early as possible. So I'd do all the scaling in Blender before exporting.
To do so, it is best to set Blender scale units to "metric"

(if not already so) and then scale everything to real-world size.
The most important step is now to

apply all transformations. Then, your exported geometry should come into Godot the right size so your physics will be all correct.
As for your concern that blender physics could not handle real world sizes: This may be somewhat true if the real world objects are very large. If you want the truck to behave realistically, it should have its real size.


Blender as no builtin automatic update system at the moment, you always have to download and manually install new versions.
They are for the most part backwards compatible except for major versions like the jump between 2.49 to the 2.5 series, or between 2.79 and the 2.8 series. Apart from some small additions or changes you should always be able to open your files without problems on newer versions unless stated in the release notes.
If there is no particular functionality from the dropped features list you specifically need, and if your hardware is compatible with newer versions, it is always advised to upgrade, unless you are in the middle of some critical project, commercial production work, or a complex scene, in which case you are advised to finish your work before messing with the software installation.
New versions can bring bugs and introduced regressions or some time have issues with newer driver and hardware.
If you want something close to an auto update system you can try the Steam version of Blender.


How can I properly form text from particles?

To change the shape of an object using particles, use the physics type Keyed.

Create an emitting object, cube or whatever.
Create a text object, convert it to mesh Alt-C and add another particle system.
Create a controller (e.g. simple plane with a 3rd particle system) and add the previously created particle systems as keys.

Here with a tiny version of the cube used as Dupli Object.
Use a massive number of particles not just a few hundred.

Tutorials

Blender Keyed Particle System Tutorial
Blender 2.68 Tutorial - Various Text Reveals
Blender 2.6 Tutorial - Keyed Particles versus Curve Guides


Rotate object "Like Center Mouse Button"

You can move the camera exactly as your would move the viewport by just enabling "Lock Camera to View" in the view section of the properties panel (n), and then move your viewport: your camera will automatically follow.


Merging mesh parts that use the same texture and shader

If you select one part in Blender then double tap the 'a' key, it will select everything.

If you press 'Ctrl+j' it will merge all the parts.

Unity should now only see one mesh, material and texture.


First you may try the Delay Falloff node, it will rely on the order of the objects.

If the order of the objects is not what you want, you may consider using the Selection Order ID Key Method:

Check the Documentation for other ordering methods.

And of course you can sort objects using the Sort List node, and sort objects by name:

Or based on the object's y location.

Or in a slightly more complicated method, by using the formula e.location.y + (e.location.x)/1e5 Which will make the animation start from the left instead of the right. Which is exactly what you want I suppose.

Exact solution to your problem:

Lets say your grid is composed of n objects, you instance the cube 2n times, n cube for the right one and n cube for the right one, so 2n in total. Then you edit the first n objects as you wish in whichever method you like, then you offset the final vectors couple of units in the required direction and then combine both the unoffsetted and offsetted vectors and transform the objects based on them.


How to export an FBX file with textures?

The FBX format can't do that, you will need to export your textures manually then plug them when importing your model.
If you want to export your model with the textures assigned to the Principled BSDF then import them automatically use the .glb (lighter, recommended) or .glTF file format.


I think I've worked it out: in the Compositor, remove the Render Layers node and add an Image Node and a Denoise Node like this:

Now open the first image in your sequence, tell the Image Node that this is indeed an Image Seqeunce and choose the number of frames it has.

Now you can render as usual and see the result, either as a single image or as an animation. Specify the number of frames to be rendered and your output path as if this was a 3D scene.

Note that the results of applying D-NOISE this way are far inferior to applying it during a render. I guess OptiX has a lot more information to work with when the 3D scene is loaded, as opposed to seeing only the 2D image. Here's a comparison between D-NOISE when a applied with a render, and after the fact. Notice the loss of detail in the second image.

In regards to D-NOISE not kicking in: try starting Blender as an Administrator (if it's a Windows system). I've had the same issue with some of my nodes, when run as Administrator D-NOISE behaves fine.

Hope this helps!


I'm not totally sure if what you are saying is possible. Someone else would have to comment on that.

However, I do know what I would do to fix it.

Create a new object for each section you would like. (Tip: perhapse you could use empties to avoid step 4)
Parent your new collision objects to the main object for which you are tracking collision.
Set up the scripts so that when one of these objects is hit, it sends a message to the parent object.
Set these collision objects to not be rendered and not affect physics simulations (gravity, collision, etc.)

I hope this method helps.

Thanks, Uncle Snail


Particle System not utilizing UV mapped texture

You need to be emitting the particles from the Faces not the Vertices.
Think about it, you are trying to control the distribution of the particles with a texture, textures are mapped to the faces.

In the particle settings under the Emission section change the "Emit From:" value to Faces.

Now if you edit the UV map, you may need to refresh the particle system. You can do that by toggling it to emit from Verts then back to Faces.

That right there takes care of 95% of your problem.

(I changed the color of the spheres to be red just to show up better)

To fix those last few stragglers, just bump the contrast of the texture up a bit. There are a few pesky gray values in the texture (probably from some island), that is what is making the icospheres appear in the ocean.

Make sure you are changing the particle's texture, not the material's texture.
Open up the Color section and increase the contrast (I found that 1.1 worked fine here.)


My guess is that you just upgraded Blender, and didn't click 'Copy Previous Settings' in the splash screen. This would copy your settings of 2.78 to 2.79; without this, Blender uses the defaults after an upgrade.

If you haven't saved new settings yet, the 'Copy Previous Settings' button will still be available in the splash screen. If you want to remove your 2.79 settings, you have to visit a platform-dependent path. These paths are documented in the Blender Manual.


How to change an unknown diameter of a hole to a specific size?

Another way to achieve this is using the LoopTools addon's 'Circle tool'.

If the addon is not active on your system, go to the User Settings (CtrlAltU) > Addons > Mesh > LoopTools and activate it using the small checkbox on the right:

In Edit Mode select the loop or loops you want to resize, then either from the Tool Shelf > LoopTools or the Specials Menu (W > LoopTools) choose the 'Circle tool':

Toggle the "Radius" option on, then type in the radius you want (diameter / 2) for the hole:


You can use the 3d View combined with the already unwrapped UV to paint the texture. The relevant part is:

  Paint the mesh in the 3D View, and let Blender use the currently selected UV map to update the UV Texture ("Projection Painting")

To do that, you first need to unwrap your object which you have done. Nice!

Second, you need to switch into texture paint mode

You will see on the right panel a message that says "Missing Data" You don't have anything to paint on yet! Select "Add Paint Slot" and choose Diffuse Color

From here you will be prompted to choose a size of the canvas, and to name it. I suggest you start with 2048 as it is easier to scale down than scale up. If you need to get up close and personal with your road, use a higher resolution.

We're almost at the fun part!

if you go to your properties window, you can see that a new material has been added to your object. Great! But, its all black. Not so great. To fix that we need to navigate one more tab to the right and see the Textures Tab.

Cool! I have renamed this base texture (the Canvas) as DiffuseRoad because we are building a road. However, we need another texture to paint ON to our canvas. To do this, select the texture box below and choose "New Texture". Open your road texture image in this texture and name it something useful: In my case, I only have assets of wood so I chose my wood texture and named it "PaintTexture" because thats what we will be doing with it!

From here, return to your side bar and select the "texture" red/white checker icon. Choose your texture, in my case "PaintTexture"

Now paint directly onto your 3d model! You should probably adjust the strength to 1 instead of .5, unless you do plan on mixing with a few textures. If you do need more textures, just go back to your Textures tab and add some more the same way as previously and select them.

Now select the DiffuseRoad texture that was created for us and choose it to be our UV Background, that way as you paint your model you can see in real time how your UV will look.

Once you are happy with how you have painted your model, be sure to save the UV as a separate image so you don`t lose it!


Why is my World shader with a gradient in 2.8 only showing some of the colours in my colour ramp?

I solved this for myself after a bit more fiddling around. I'm not quite sure what I was doing wrong, but I figured I'd post this for others, because it's somewhat simpler than the setup in the linked question.


I found the solution I was looking for. The trick is to not use the same bones for twisting and IK. Use one set of bones for twisting, and another set for IK.

Setup a rig similar to what I intially mentioned (two forearm bones for twisting)
Add a new "parent forearm" bone that will serve for IK (or manual posing) purposes, parented by the upper arm or shoulder bone. It will run from the elbow, all the way to the hand. Set this bone to not deform. For IK, this bone serves as the primary forearm. For FK, it serves as a handle, basically. A container - so you don't have to manually pose both twist bones. If you export for game engines, you won't need to include this bone.
Setup both twist forearm bones as children to the parent forearm. These should be full deforming bones with weights or whatever.
Set the hand bone as a child of the parent forearm, inheriting full rotations.
Add the IK constraint to the parent forearm bone. You will need some other bone as the target for the chain.
Add a copy rotation of local Y to the twist forearm bone closest to the hand. If you use more than one twist bone, you will need to add this to the others as well.

I think that's it. Let me know if I missed something. I found this video, which helped tremendously: https://www.youtube.com/watch?v=Vm7ST03SW8Y ..I honestly don't like the way he set up his vertex weights, and don't think its necessary to use more than one joint for forearm twisting, but otherwise, the setup seems solid and achieved exactly what I needed. Hope this helps someone looking to do the same thing.


I would recommend looking at the themes section of user preferences. There you can not only find out what all the colors mean but also change them.


How do I recover missing polygons using a UV MAP

AFAIK it's not possible to reconstruct missing polygons with only the help of a UV map. The UV map contains not all necessary information about the vertices' location within the 3D coordinate system.

You might be able to close holes in a mesh with Blender's "fill holes" function, but that most possibly requires you to reconstruct the UV map as well.


How to tell which object uses which animation/action

Actions are globally stored in bpy.data.actions, regardless of scenes.

Every object can reference one and only one action (Object.animation_data.action). Thus, you can't know which actions are made for / compatible with which objects without extra work on the user oder coder side.

User-based solution:Let the user specify which actions are supposed to be exported for which objects, either in a Panel in the export file selector or for every object in the object tab - both are not ideal. The former needs to be re-done every time (unless presets are used), in the latter renaming actions will break it.
Programmatic solution:Check all FCurves' data_paths and see if these properties are available for your object type. This should work reliable to distinguish Armature actions from other more generic ones, as the data paths start with 'pose.bones' for Pose actions.


How can I make my particles emit from the emitter object moving by key animation, instead of the emitter's default position?

Particle System has a bake option you wil see in the Panel.  You will probably need it.

If you have a previous bake.  Delete the bake.  Then bake again.

If you never baked.  Try baking for the first time.

Remember to bake after every significant change.  The particle system will not let you change parameters when a bake is active.  Yet you can change other objects such as physics obstacles. I have not checked every version of Blender 2.8X yet at one point there were obvious defects in the Particle System.


Switching or selecting the Object associated with ObData (Mesh)

I believe I found the one answer.
Select the original object that was duplicated and then use:
Select > Select Linked > Object Data (Shift L)
However, what happens if you have inadvertently deleted the Original Object?


How can i make hollow cylinder but to be closed on top and bottom only hollow inside?

Add a circle mesh.

After that, go into edit mode and extrude it down by selecting all the vertices, pressing E, and then dragging down on the z-axis. Then, select  all the vertices on one side of the cylinder you just made and press F to fill it in, then do the same on the other side. You can use box select to select all the vertices faster (press B and drag out).


How to add a shortcut for 'Reload Scripts'?

New shortcuts can be added in the preferences Edit > Preferences > Keymap.

With the keymap tab open, navigate to the Window category of shortcuts. Click the Add New button to create a new shortcut. The operator for reloading scripts is bpy.ops.script.reload() therefore the identifier for the shortcut is script.reload. Click on the shortcut field and press F8 to set the key binding.

In the default keymap for Blender 2.80 there is no existing key binding on F8 which means you can add the shortcut without any problem.


Go to edit mode, select your mesh and Press space and type fill holes and select the option and then go to the left panel and change the sides option to 5 or 10 (change it if it doesnt do anyting)


After using the greas pencil to create your drawing, you can use the build modifier to animate the draw-in along the stroke.