How to make ivy's leaves colored randomly?

I will post several possible ways to achieve this kind of task.

First way

Basically, the most intuitive way is to use separating every single leaf into new object by using P > By Loose Parts and it's already described here (also some tutorials about modeling and rendering ivy use this technique as well).

The main downside for this is that it needs large amount of computations and may freeze PC for some time. More than that, after the procedure is finished, the 3D Viewport still will response much slower because there will be way more objects in the scene to take into account (in case of one not very large ivy  ~5000 objects, i.e. leaves).

Second way

Some great solutions are provided in this thread. There are several of them (at least 3 different ones):

using Random group connected to Color Group;
using UV Align\Distribute addon (thus creating UV Map) and a script executing
and the third one already listed here above

The main reason why I decided to go further is that I wanted to get possibility to setup this color randomness really fast so to test some ivys while modeling environment scene (and also I didn't find that thread from the beginning).

Third way

This way assumes using 2 UV maps, one for different leaves' color, while another - for actually the texture (image based). Basically it is one of those listed in the BA thread (except for the script), only combined with another solutions.

After the ivy is created, it has UV map by default, and it's for actually image texture as is told above.
Therefore create one more UV map (I called it "Leaves-1"), it willl serve for different leaves' color task. With this map selected and set to active, enter Edit mode, U > Lightmap Pack (you may also use Smart UV Project option as well, it will fit ivy leaves' needs).  After this is done, with leaves still selected, in Object Data tab, UV maps scroll hit that small camera button next to the default map so it to be one used for rendering.

Now, setting nodes part.
Basically, the nodes will be the same as they are in case of leaves / plants creating - with alpha mask using, along bump and normal maps etc. except for one thing. Instead of using Object Info node (with Random output used) what should be done if using  first way, UV Map node will be used with newly created UV map name assigned:

ColorRamp used here will determine difference between leaves' image texture color. The result on the left is with bottom ColorRamp used. The result on the right is an attempt to add several hues, so I added Mapping and Separate XYZ nodes and added one more color stop in the ColorRamp:

It is possible to change ColorRamp interpolation mode to Constant, the difference of the leaves' color will be somewhat sharper. Also some colors will become more visible (brownish in my case)

Advantages

There shouldn't be done no additional computations
Only one extra step required - this may be set up very fast
The color manipulation is rather easy and comfortable (with ColorRamp)
The result is looking somewhat convincing

Disadvantages

Some sharp color transition within one leaf sometimes may happen, especially with Interpolation mode set to Constant in ColorRamp
It's not the best solution if adding more colors to color stops is needed, it may not handle them all correctly
Because of combining color and image texture is done with MixRGB node image texture may become less visible (if the color appearence is set to high)

Addition

And with mixing one of solutions from the Second way with this one the result may look like this:

This can be achieved by connecting Random group (instead of UV Map node) to the ColorRamp from the 3rd solution. Random Group is proposed in that BA thread:


Camera moves location when rendered. Why?

Without seeing the file, I kind of don't think it is an object (butterfly) problem. My guess is that you have different viewport and camera focal length and/or shift settings (make them the same). Maybe you have lock camera to viewport on. Turn that off (in the right side tabs).
Also maybe instead of appending try opening both blender files in separate 'blenders', and then copy/paste the butterfly object rather than appending. You might be appending some subtle thing that gets pulled in by the append functionality.


Can I use weight paint in the middle of a face?

Welcome to Blender Stack Exchange! Weight painting specifically weights vertices, so no, there is no way to weight the middle of a face. A vertex is the most basic piece of a mesh, so in order to define how a mesh should look or behave, it needs to have vertices wherever you want there to be detail/information.


Can I export a render of the material view mode?

Yes, it is possible, it is called OpenGL rendering. The leftmost buttons on the bottom of the 3D View will do this:

You will get a rendering of the current viewport, either a still picture (left) or the full animation (right). Just switch to Material view and press the button.


With the help of @B.Y.O.B. I realized that it's not possible to change "pass" setting, because LuxCore (and also Cycles) processes all selected passess (AOVs) while rendering, so there is no point in changing that variable with python (therefore it's not exposed to the API).

Anyway, my final goal was to output only certain pass (in my case "Irradiance"), which I achieved with standard way for manipulating render output - Compositor Node Editor. I used File Output node as shown on my code example:

import bpy

bpy.context.area.type = 'NODE_EDITOR'

bpy.context.space_data.tree_type = 'CompositorNodeTree'
bpy.context.scene.use_nodes = True

C = bpy.context
node_tree = C.scene.node_tree

render_layers = node_tree.nodes.get(Render Layers)

# This command creates File Output node
node_tree.nodes.new(type=CompositorNodeOutputFile)
output_file_node = node_tree.nodes.get(File Output)
output_file_node.base_path = "save path"

# Link Render Layers to File Output node.
irradiance_output = render_layers.outputs.get(IRRADIANCE)
link = node_tree.links.new(irradiance_output, output_file_node.inputs[0])


Bevel goes in wrong direction and creates disortion

Welcome to Blender Stack Exchange!

I just downloaded the file and inset the ngon like in your first image. I got the same results as you did, but recalculating the vertex normals fixed the issue.

This can be done by selecting everything in edit mode and pressing Shift+N


How to randomize particle effects along a curve guide?

As far as i experimented with my project, I couldn't find a definite solution. However,I was able to bypass the problem. I aligned the normals of the emitter along one of the axis, then with required level Brownian Motion set, I increased the Normal velocity of the particle system. Later I baked the Particle System, however this step was of my preference.
Similar results can also be achieved by setting a Particle System with the necessary -- Brownian Motion and Normal Velocity -- settings along with a Force Field of negative strength. Note that both the Particle System and Force Field have to exist on the same Layer. Also, a Force Field affects all particle systems present on the layer. Therefore, while using multiple particle systems place each of them on a different Layer if you don't want the Force Field affect them too.


What What happened to the mesh display panel in blender 2.8?

It's now called Viewport Overlays and located next to the viewport shading options.


Masking geometry without breaking constraints/parents

If you are using cycle ...

You can turn off certain types of ray visibility for individual objects and the camera will ignore them.

NOTE
If this question is more complex than it seems I advice you to upload more images and even a portion of the .blend file so someone could download and dissect the problem.


How do I change the shortcut icon back? v2.81

Ok after some more playing I found it. Any of the icons with the arrow in the corner you can left click and hold to bring up a sub menu.

Also using the keyboard shortcut for box select will change the icon to that again.


What's the relation between Cycles' sampling pattern and the pixel filter?

Simple Answere

  What is the link between these settings?

The Pixel Filter randomly changes the coordinte of every sample with the given distribution, meaning for example: When the Sobol Sampling Pattern samples near the edge of the pixel, the neighbouring pixel might be lit instead with a rather high probability. This is used to get rid of aliasing on the sharp edge of very bright objects, like mesh lights.

Look at these examples with a mesh light with a strength of 100. You can see the noisy Gauss distributed white dots during the whole sampling process.

Gauss with width of 0:

Gauss with width of 2:

Gauss with width of 10:

With more samples the last two would both result in a smooth image. The higher the width of the Gauss the less antialiasing you get, but at the cost of loosing some sharpness.

  Could one use a sampling pattern that goes outside of the pixel boundaries to combine the sampling pattern and filtering into a single procedure?

Actually, this is a not a bad idea, but I never heard of any renderer doing this. Convoluting the Sampling Pattern with the Pixel Filter and using the resulting function as the new Sampling Pattern should result a render that converges to the same image.

This is however not desired probably because being able to separately choose these two functions rather than from a huge list of all possible convolutions is better. And the common Pixel Filter functions are used in other type of renderers, where sampling is done over the whole image rather than pixel-by-pixel, and one sample really lits multiple pixels, which is not stochastically sampled but fully calculated, like LuxRender.

Mathematical Explanation

First Possibility

Given the i-th columns k-th pixel indexed from 0, the Sobol Sampling Pattern gives a uniform pseudo random 2D vector (x, y) inside the [i, i + 1) x [k, k + 1) set, which is the mathematical notation for the square of the pixel. The rendering engine traces the related direction and returns with the color. The Gauss Pixel Filter samples a Gaussian distributed pseudo random 2D vector (dx, dy). The pixel containing the (x + dx, y + dy) vector gets lit with the traced color.

Probably this is done in Blender.

Second Possibility

Given the i-th columns k-th pixel indexed from 0, the Sobol Sampling Pattern gives a uniform pseudo random 2D vector (x, y) inside the [i, i + 1) x [k, k + 1) set, which is the mathematical notation for the square of the pixel. The Gauss Pixel Filter samples a Gaussian distributed pseudo random 2D vector (dx, dy). The rendering engine traces the (x + dx, y + dy) related direction and returns with the color. The original pixel gets lit with the traced color.

Why these result the Same

For every x, y, dx, dy where (x, y) is contained in the i-th columns k-th pixel pixel and (dx, dy) is a possible outcome of the Pixel Filter, the events below have the same probability:

First Possibility: The Sampling Pattern sampled (x, y) in the mentioned pixel and the Pixel Filter sampled (dx, dy).

Second Possibility: The Sampling Pattern sampled (x + dx, y + dy) in some pixel and the Pixel Filter sampled ( - dx, - dy).

These events have the same probability because all Sampling Patterns have uniform distribution and all Pixel Filters have a symmetrical distribution.

This means that both possibilities converge to the same image.


Certain faces refuse to be selected, yet others on the same object slect fine

Due to the way Blender detects selection, for large faces you sometimes need to click on or near the selection dot in the middle of a face to select it.


Is there a way to realign a not aligned object, which tranforms has already been applied?

This is a duplicate answer: I can't find @moonboots' original. If found, feel free to delete this one.

Decide which face you want the object to lie flat on. In Edit Mode, select the face, and create a Custom Orientation from it. (In 2.79, CtrlAltSpace. In 2.8,Header > Orientations dropdown > '+')
With all the object's vertices selected, CtrlH hook them to a new Empty. They are now frozen, while you transform their local axis.
In Object Mode with the object to be aligned selected. In menu Header > Object > Transform, click 'Align to Custom Orientation'
Go to the object's modifier panel, find the Hook modifier, and apply it.

Now the object's local Z axis will be oriented normal to the chosen face, and it will be easy to rotate the object to align it with the world, or, by snapping, to any other face. You could, if you want to, ShiftAltO pt yhe origin to center of the face, too.


Stencil image for texture painting shifted too far away from viewport center

Hold right mouse button, click on the image to move.


There are several ways to do this.  The two that I think are most straightforward are:

Subdivide the 4 edges that are coaxial with the direction you want to "shrink" the mesh in.  Slide the verts along the existing edges to where you want them to be and connect them by subdividing (knife tool) the existing faces.  You can then delete the faces that stick out (there should be 5 of them) and create a new face using the new vertices.
Boolean operations.  I'm not exactly sure why this isn't working for you, but I have a few guesses.  First, both objects you're using have boolean operations configured, but not applied.  You may need to apply the boolean to the first object ('stand') before it can be used on another object ('Astand').  Second, it looks like the faces of your objects are coplanar, causing a well known problem commonly known as Z-fighting.  This should be resolved before applying any boolean operations.  Finally, it can be hard to tell if a boolean operation applied successfully when all the objects are still visible.  I'd turn off the visibility of the object you're subtracting ('stand') while leaving the object you're subtracting it from ('Astand') visible.


How am I supposed to move only Gizmo when in Edit mode?

Exactly... You can easily solve this using the 3d cursor...

First be sure that you set the pivot point to the 3d cursor (in object mode):

Back in edit mode you select the edge where you want the center of rotation and hit Shift+S to set the 3d cursor to that edge:

Problem solved, if your cursor is at the right place you can rotate everything around that point:


Export 2D Camera Motion as a vector for Vector Blur Node

Here is what I did to get it to work. (I didn't add an explanation to my comment, because I essentially just did, what you described in your question.) Anyways, here it goes:

I'm using Blender 2.79.

My Scene only contains a camera and an image plane, which I added via "Images as Planes". Then, I added keyframes to the Camera Rotation. I modified X-, Y-, Z-Rotation with a Noise Modifier.

I turned off Motion Blur in the Render Tab

And here are the Render Passes I used:

Then, turn on Compositing under Post Processing.

This is my Node Setup to add the Vector Blur:

Which gives me this result:

Note, that the image plane is NOT moving.

Have a look at the blend file:

EDIT:

A little side-note, that I've just noticed:

When I look at the vector pass (by Ctrl + Clicking with Node Wrangler Addon) I only sometimes see the actual colors in the viewer. Other times the viewer shows nothing. But this seems to be only an issue with displaying it, because, when I left-click on the viewer, I actually get a values at the cursor position. This can also be confirmed by saving it out. - The I get this picture, even though the viewer shows nothing:


My finished model looks like this. Of course topology may be different- it's your decision how you set the edge flows. Here's the .blend for you to study:

It's too broad modeling task to describe every step, that's why I used a screencast keys in my .gifs. Begin with extruding the cube horizontaly, then subdivide it using edge loops (Ctrl+R). Add a circle (with 8 vertices) and bridge the extruded cube's end with it (W-->LoopTools-->Bridge). Your base mesh is ready. Rest is a matter of using blender modeling tools to tweak some vertices as pictured below.


Using a hint/information-bar like the trasformations are using

You do this by using Area.header_text_set()

Here is an example using the Modal Operator template:

import bpy
from bpy.props import IntProperty, FloatProperty

class ModalOperator(bpy.types.Operator):
    """Move an object with the mouse, example"""
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

    first_mouse_x = IntProperty()
    first_value = FloatProperty()

    def modal(self, context, event):
        context.area.header_text_set("Well see? Its working...") #add text to header
        if event.type == 'MOUSEMOVE':
            delta = self.first_mouse_x - event.mouse_x
            context.object.location.x = self.first_value + delta * 0.01

        elif event.type == 'LEFTMOUSE':
            context.area.header_text_set() #on confirm restore header to default
            return {'FINISHED'}

        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            context.object.location.x = self.first_value
            context.area.header_text_set() #on exit restore header to default
            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        if context.object:
            self.first_mouse_x = event.mouse_x
            self.first_value = context.object.location.x

            context.window_manager.modal_handler_add(self)
            return {'RUNNING_MODAL'}
        else:
            self.report({'WARNING'}, "No active object, could not finish")
            return {'CANCELLED'}

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

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

if __name__ == "__main__":
    register()

Note that using header_text_set without an argument restores the header to default.


As per Antonio Vazquez, Blender Developpers, the issue was the leak size.

It should be defined as 3px, in my case it was 35.

I was also advised to download the new version of yesterday.

It works now.

FYI, the architecture was slightly modified, the brushes and specifications don't appear anymore on the top but on Active Tool and Workspace settings tab, under Brush.


If you're using Blender 2.79, and you right-click instead of left-click, you cancel the operation. use the Left mouse button to create each vertex then press Enter to finish off.


I believe the Glossy material type in luxrender does what you want out of the box.

Unlike the glossy shader in cycles, the luxrender glossy material includes a "matte" component (diffuse in cycles-speak), making it loosely analogous to the following cycles setup:

Luxrender glossy node for reference:

Render comparison

Cycles

Luxrender

I'm not really sure why the cycles render is dimmer than the luxrender example in this case. The difference appears to be in the diffuse part of things. If someone knows what's going on here, I'd definitely like to hear about it


Is there any difference between bpy.path.basename and os.path.basename?

os.path.basename doesn't understand Blender's // prefix (denoting a path relative to the current blend file). bpy.path.basename does understand this. If your path is (or could be) a blend-file-relative path, use the bpy.path.* functions.

On Linux I don't see any difference either, don't have Windows handy at the moment to check there.


Here I tried another node to see the difference


Home key for best fit, works for all panels.
Scroll up or down to adjust at your convenience.


Your HOLE PUNCHER NOPE object seems to be a pretty much a revolution object, it could be easily and cleanly modeled by drawing a simple profile and using a screw modifier.
That will yield a cleaner consistent geometry that will be error free and less prone to errors using boolean modifiers

Recreate your object from scratch by draw a single continuous bi dimensional edge profile by extruding from a single vertex and tracing over your existing object with snapping to make it easier. Then you can add a Screw modifier to it.

Recalculate the normals on your "BOTTOM" object, add the Boolean modifier and it should work.


How to randomly render credit card number values with Python scripts

Here is an Animation Nodes solution:

Which produces:

It works by taking a frame number and using it as a seed to generate 4 random strings of 0-9 characters. Each node has also its own seed, they should differ, so you get 4 different numbers from a single frame number.

Last step is to join the strings together into single one with a space separator in between:

To fool the average viewer the solution above is enough but to be correct more math should be involved which is not hard but would clutter the example. Not every made up credit card number is valid. Each CC company has some rules the numbers should obey and they also differ in length:

Payment card numbers (wiki)

The last digit is also usually a checksum number that can be calculated using Luhn algorithm (Mod 10).

A starting point to get a list of random digits that you can do math on and then convert it to text could look like this:


It seems that the way to go about it is, unintuitively, to exit edit mode into object mode in order to perform any vertex-level stuff, and then re-enter edit mode at the end of your script.

mode = bpy.context.active_object.mode
bpy.ops.object.mode_set(mode = 'OBJECT')

ob = bpy.context.active_object

for vcol in ob.data.vertex_colors:
#sample or do stuff to the vertex colors

bpy.ops.object.mode_set(mode=mode)


The problem here is that you are using Screen Space Reflections.
Eevee uses various shortcuts in order to get good visual renders with minimum render time. In the case of reflections, Screen Space Reflections usually produces results which are good enough in most situations - where everything that is 'Visible' (screen space) is mapped through any reflective surfaces to provide those reflections. This means that only things that are in 'line of sight' need to be rendered but has the downside that if anything would only be visible as a reflection that it will not be rendered.
In your example, the dark shadows you can see in the reflection are those bits of the scene which are not directly visible to the camera - ie, it is behind the cube. Since the reflection provides a view of that 'hidden' section, Eevee cannot render it - and so it shows as an additional dark shadow in the reflection.
The solution is to use a Light Probe (in this case you can use a Light Probe Plane on the floor) to give Eevee a hint as to what to consider for reflections.


No
No cleanly, you can re-define the classes from source .py ui files in your addon. Which is dirty.


When I import images as planes it shows a random line at the top

Image textures employ interpolation to blend pixels into the neighbouring space so as to smooth the image rather than provide a hard pixelated effect. With the image set to Repeat there is actually a copy of the image just beyond the image borders. In your case the image against the opposite edge is butter right up against the edge and so the interpolation is causing it to 'bleed' across te border - the bottom of your grass image is bleeding into the top.

To resolve this, simply set the image to Clip rather than Repeat.

The option is located under the "Texture" panel:

If you're using Cycles

If you're using Blender render


"bpy.ops.rigidbody.world_add.poll() failed, context is incorrect" occurs when python script is ran more than once

When you first start Blender there is no rigid body world added to the context. You can check this by running print(C.scene.rigidbody_world) in the console. This should return None
When you run bpy.ops.rigidbody.world_add() you are adding a new rigid body world to bpy.context.scene If you now enter print(C.scene.rigidbody_world) you should get something like <bpy_struct, RigidBodyWorld at 0x00000225720128B8>
If you immediately run bpy.ops.rigidbody.world_add() again the error you get should be something like RuntimeError: Operator bpy.ops.rigidbody.world_add.poll() failed, context is incorrect This tells us that the operator's poll() method is checking "something" in the context and since we know that what has changed is that we now have a rigidbody_world in our context, we can assume that this is what the poll function is checking for. (actually checking this is a bit of a pain as it means tracking down the operator)
Wrapping up - you have two options.

remove the rigidbody world using bpy.ops.rigidbody.world_remove() before rerunning your script
Check if there is already a rigidbody world added before adding one and skipping if there is.


The Snap uses the object's Z axis to stick perpendicularly to the target face, so in your case you need to rotate the origin 90°, at least temporarily:

Enable the Affect Only Origins option in the Options panel on the top right of your 3D view:

Rotate the origin so that its Z axis points perpendicularly to its current orientation:

Disable the option, move your object until it snaps to the face you want:

You could also simply stick the object and rotate it on its own X or Y axis with R and double X or double Y.


The normal map you are using is baked for tangent space. Blender tries to calculate the tangent and binormal vectors from a UV map. The problem here is that along UV seams the tangent direction can change. This is why you get weird shading along the UV seams.

A simple solution is to calculate the normalmap in Object space (use "Object Space", not "Blender Object Space" in the Cycles shader). However this will not work if your object gets deformed, for example by animation bones. Also there still seem to be some artifacs and the normals seem not to be calulated smoothly (see red box below).

Using the displacement texture directly instead of the normal map gives you perfectly smooth shading, so I think you should it instead.

Apart from the texture issues your object also has a bunch of flipped normals: inside the nostrils, the eye sockets and inside the holes where the ears are attatched to the head.


MIDI to IPO/Drivers
possibly: https://github.com/kwnetzwelt/midi_to_ipo (for blender 2.5 onwards)
It imports MIDI (per track) and converts it to IPO/drivers and comes with a well written getting started.rtf document.


You can use a mix shader with the two label shaders as the shader inputs, and a black/white image as the factor input on the mix shader.

On the black/white image, where there is black, there will be 100% of one label. Where there is white, there will be 100% of the other label.

Edit to elaborate;

To achieve this result;

I used this node setup;

And these black/white textures;

I have packed the .blend file for examination:

Explanation

So, most of this is just simple UV mapping and textures.

The 3 label textures are fed UV Mapping nodes which are, themselves, all fed the same Texture Coordinate node.
There are two additional textures (which I painted directly in blender, but you can create them however you want) that are just black/white images, which define values between 0 and 1 (you could technically use some shade of gray to partially mix the textures, but since you specifically don't want that, you'll want to use either flat black or flat white)
I pass the black/white images through a RGB to BW converter because technically they're color images, and we just want values to feed to the MixRGB nodes (which can be found in the "color" section). This is the part right here that allows you to mix these labels without creating separate sharers for all of them. Important note: I noticed that you wanted one shader to be glossy, and another to be more diffused. This method can technically make that happen, but it would be much easier to use mix shaders for that. Happily, the black and white image examples in this file would work the same for mix shaders as they would for MixRGB nodes.

Also, on the black and white images; You'll see that one of them has white on the top 2/3rds, and the second has white on only the top 1/3rd. This effectively tells the first mix "Yes, also pass through the top third for later mixing"

Notes

I did this really quickly and dirty. If I'd spent more time on it, I would have defined separate UV maps for all the labels and the black/white mix value textures. Since I didn't do that, I used the UV Mapping nodes to squish the labels to the (mostly) correct proportions, and move them up and down on the (very tall) "can".


Keep objects from intersecting each other when positioning them?

I really wish Blender supported this out the box and it could be as easy as enabling/disabling 3D manipulator. But the simplest way I found is the following. Assuming you started with default scene with a cube:

Enable Rigid Body for the cube in Properties > Physics and select the first Cube and Properties > Physics choose Passive for Rigid Body > Type.
Duplicate it (ShiftD) and move (G, X) new cube somewhere so it does not touch original.
Set End frame to big number, for example, 10000. Make sure Properties > Scene > Rigid Body World is enabled and set End in Rigid Body Cache to the same big number (10000 in this case). You also may want to disable Gravity.
Select the second cube and duplicate it and in Edit mode with pivot set to Median Point scale up the third cube slightly (for example, 1.01), set its Maximum Draw Type (in Properties > Object > Display) to Wire. In Properties > Physics > Rigid Body Collisions choose Mesh as Shape and (assuming 1 BU = 1m) Margin to 3mm (if it fly away immediately when you start playing animation at step #6 - try smaller value and return to frame 1 to start again). Go back to Object Mode.
Select the second Cube (the one you actually want to move) and in Properties > Physics choose Active for Rigid Body > Type.
Click Play Animation. To manipulate, select the third cube (displayed as Wire) and move it. Second cube will follow and Rigid Body Physics will do its best to prevent collisions, but if you force it too much, it may fly away; if it does, press Esc and go back to first frame to try again. To put it on other object without intersection, move it slowly, when it start shaking it means slight intersection happened, move it away a bit and when it stops shaking, stop moving. When done moving/rotating, pause animation, select all, CtrlA to Apply and choose Visual Transform and then go back to Start frame.

Obvious drawbacks is that you have to enable Rigid Body on objects and create temporary object to move object you want to move, then delete temporary object, not to mention the temporary object introduces problems - direct manipulation would be much more convenient.


Why does moving one side of my rigged character move the other side as well?

Why?

As Mike Pan mentioned- this is because you have a mirror modifier on your mesh, not your armature.

How to fix

Either A. Apply the modifier or B. Remove it

-Happy Blendering!


Make sure you use constant offset in the array modifier.


You can click on any main icon panel (the first one) and choose Info.


You've just stumbled upon a unique feature of the compositor!

Yes, if your Scene>Dimensions>Resolution settings are not at 100% you won't see your full image.
The compositor doesn't automatically rescale images (or video) to fit the size used in the dimension's settings. When you render at 50% resolution, for example, it considers the composition to be half the number of pixels. The images in the image nodes get partially displayed because the picture size in pixels is not the same any more, but twice the size of the comp.

The workaround, if you want to work at a smaller resolutions, is to use a scale node with values that match your render settings. (But don't forget to turn it off a the end when you do the final render at full res!)


Cube doesnt show all the faces when orbiting, depends on a viewer angle

selected the object, edit mode, select all, hit T, to the shading/uv's tab, scrolled it a bit down hit either recalculate (should fix it instantly) or hit flip direction (this is best if you only select the faces that needs to be flipped).


As far as I understand your question, node groups should work just fine. You can define exactly what parameters you want as input, and if a node has a 0 weight in a mix shader, then it will not be evaluated.
EDIT The manual says clearly that you don't need to worry about Mix Shader nodes performance.

When executing shaders, a special optimization is applied to Mix Shader nodes. If Factor evaluates to 0 or 1, any nodes that are only reachable via the unused branch of the mix are not evaluated.
This can substantially reduce the performance cost of combining multiple materials in one shader with vertex color, texture, or other input used as a switch.

Also Python code can control the material properties inside the node tree, and for this Python code you can create your own Python panel: Control Cycles material nodes and material properties in Python


Can I enable antialiasing in the solid view during orbit / pan?

You can control the Viewport Antialiasing from Preferences > Viewport > Quality:


Is it possible to record the bevel factor as a keyframe in the action editor?

it's because bevel depth is not an object property - it's curve data property. Action editor shows only one animation block (bordered with red line):

Outer animation blocks doesn't display in action editor

So what you can do - create a property in object data and make driver to manipulate bevel depth value in curve data
through object data.

Howto:

In object data find tab custom properties  and add one:

Next, open curve data side by side and press RMB on bevel depth:

Chose add driver -> single from target, and (when your cursor will be as dropper) click on value created before.

So now you have value in action editor, that manipulates bevel depth:


In the output settings select FFmpeg Video

The Encoding panel will be enabled then..

Read also this related links:

https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.79/More_Features

Blender 2.79 I only get four video output options


Transform (Rotate) with 4x4 matrix via python

I took your blend file and modified the code a little bit. At first I inserted the R0, R1, R2 and R3 values into the matrix. Then to transform a given matrix with another one you have to multiply them. The order is important.

import bpy
from mathutils import Matrix

bone = bpy.data.objects['Untitled'].pose.bones["topfrontleft"]

m = [ (-0.470458022353494, -0.807963312121372,     0.354773921630525, -6631.4567921258),
      ( 0.645229984870226, -0.589232780440685,    -0.486295174846007,  3943.31281557432),
      ( 0.601953084407421,  0.000129305847915359,  0.798531444247745,  2890.46728702281),
      ( 0,                  0,                     0,                  1) ]

matrix = Matrix(m)
bone.matrix = matrix * bone.matrix

After executing the code in your file the bone is 'flat', but instead of being parallel to the x axis (so that it matches the other edge) it is parallel to the y axis.. Are you sure that the matrix is correct? If yes you will need some other matrices to rotate it in the correct direction, but at least it's already flat :D


Textures and materials to show up while playing animation in 3d viewport

When using the viewport in render view mode, sluggish animation and freezing are not uncommon when you try to play your animation. Try setting the viewport render mode to "material" or "textured" and you should be able to play animations smoothly with your textures/materials visible and animated.

This has one caveat however, the Blender Internal render engine does not support procedural texure in material view mode, and will display the object incorrectly.


Subsurf modifier seems to prefer a vertex for no reason

Going into edit mode, I see the shading is not correct.

To fix this, select the object, go into edit mode, select all vertices and then recalculate normals (shiftn).


Transparent background for live motion capture and performance

The easiest method for me would be using green background in Blender and Chroma key filter in OBS Studio:

In Blender, set Display -> Render Only and tick World Background

Set World Background Color to green

Hide all UI so it looks like this, you can go fullscreen by pressing AltF11

In OBS Studio, add corresponding Display or Window to Sources list, then right click on the scene preview -> Filters -> Chroma Key, make sure the green is selected

The resulted scene you can live stream


How do I fix my texture appearing backwards?

Probably you just need to open UV Editor, selecet all uvs and scale on X Axis with a value of -1, which will mirror uvs back to normal

You can also mirror with a vector mapping node on shader editor


VSE: Video is imported at incorrect framerate, and setting to correct framerate desyncs audio

36.000560 is not a standard frame rate by any means (is this some screen recording or is this done with a cheap phone?). When you find those frame rates it is possible that the recorded video is compressed using variable frame rate. Blender cannot deal with such files. You will need to transcode to a standard and constant frame rate for blender to work with your file.
Or you can try using another video editing app (blender's video editing capabilities are not as developed as other apps out there).


You can replace the ocio configuration from blender, and use the one used by the author of Filmic Blender directly

https://sobotka.github.io/filmic-blender/

Alternatively, to use the Greyscale look, you can manually edit the config.ocio file in the colormanagement folder and add the following stanza in the looks section:

looks:
  - !<Look>
    name: Greyscale
    process_space: Filmic Log Encoding
    transform: !<MatrixTransform> {matrix: [0.2126729, 0.7151521, 0.0721750, 0, 0.2126729, 0.7151521, 0.0721750, 0, 0.2126729, 0.7151521, 0.0721750, 0, 0, 0, 0, 1]}


Blender 2.63 doesn't support playback:'Blender'?

Books tend to use a slow release cycle and then are available for a long time. Version 2.63 of blender included with the book was released more than 2 years ago and would have been compiled using an older system version than what you have installed now. After installing newer versions of your system and supporting libraries previous releases can stop working.

The best option would be to try a new blender version. If you have trouble with the official release versions then you may want to look at tips on installing builds made available by others or compiling blender yourself.


Can you have mesh particles that don’t intersect?

If you don't want them to intersect, then yes you should be using rigid bodies.

In the particle system settings, change the start and end frame 1 and adjust the number of particles to fit your scene. That makes all the particles spawn at the same time. Then go into the modifiers tab of the emitter object and click convert. Now each particle should be a separate object.

Then just create a rigid body sim and cache it out.


You could begin with a spiral curve (you need to enable the  Add Curve: Extra Objects addon):

Convert to mesh, fill the faces:

Add an edge loop:

Move it up:

Create additional edge loops in order to round the profile:

Clean the topology:


How can child reach parent object position and stick on it?

You can do this using Child of constraint. It works like parenting, but it has influence value. If influence sets to 0 object is free, if 1 - object follows to target.

You can make smooth transition between parenting and free position by animating this value:


You can use the new "Random per Island" output from the "Geometry" node. This only works with Cycles Renderer.


Is it possible to cause an object in Blender v. 2.79b to produce a sound whenever it is struck?

Yes, you can use a cylinder as a string and shape keys to move it up and down:

Create a new Shape Key to move up and down the string:

Then move the string up with Proportional Editing turned on:

Allow the shape key to get a minimum value of -1 to let the string move down:

Then animate the scale of the object:

Bake the sound file to the onto the scale animation curve:

Next bake the animation curve:

Copy the keyframes from the scale animation to the shape key animation:

Delete the scale, location and rotation keyframes (don't forget to set the scale back to 1.0 in all axes after this):

Finally, add some noise modifier to the animation curve to move the string up and down:


On laptop when I press F3, no search bar shows up, just the brightness goes up?

While i can't be sure, i would think, that the problem may be related to the  function key (Fn) for your laptop. Many keyboards come with multimedia keys that allow such functions, so i would not be to surprised if your laptop had an extra symbol on the F3 key that was triggered instead.

Since i do not own such laptop, i show a part of an article i link below:

Review Toshiba Satellite C855-2J4 Notebook
Jonas Adams, ✓ Stefanie Voigt (translated by Bernie Pechlaner)

As it shows, there are laptops that require you to press the function key (Fn) to access the F1-F12 keys. While without you always press the multimedia/functional keys, to control brightness and volume and so on.

Not exactly Blender related, but i hope you can continue with your Blending.


Model the tied end of a nylon/plastic bag

Modeling

Go to a new scene and delete the default cube. Shift + Add a Cylinder mesh. Tab into Edit Mode. Key Numpad 1 and then Numpad 5 to enter Front Orthographic View. Key Z to enter Wireframe View and Box deselect the top verticies (drag to create the box with the middle-mouse button). Key S then .2 to scale the bottom vertices. Your mesh should presently look like this:

Change into Edge Select Mode, key A once or twice to deselect everything, and Box select all lateral edges (the ones along the side going from top to bottom). At the bottom of the 3D Viewport, go to Select > Checker Deselect. Your mesh should have these edges selected:

Key S, then Shift + Z, then .9. Enter Face Select Mode. Select the top and bottom faces (bases) of the mesh. Key X and select Faces. Your mesh should now look like this:

Reenter Vertex Select Mode. Select two vertices opposite each other on the larger side of the mesh. Key O to turn on Proportional editing. Set the Falloff type to Random. Key S to Scale and move the mouse's scroll wheel one way or another until the white circle covers the whole mesh. Scale inwards.

Tab into Object Mode. Go to the Object modifiers tab in the Properties panel. Add a Subdivision Surface modifier. Set both the View: and Render: values to 2. In the 3D Viewport's Tools panel, select Shading: Smooth.

Texturing

Go to the Materials tab in the Properties panel. + New to add a new material. Select Add Shader from the shader drop down menu. In the top slot under the Add Shader, select Translucent BSDF. In the bottom slot under the Add Shader, select Refraction BSDF. If you go into the Node Editor, you may find something like this:

Finished .blend file:


How to avoid smooth and roundnes in my alpha brush when sculpting hard surface?

I solved it, it was an oversight on my behalf, i just selected the straight "set brush shape" option in the "curve" tab


You have unlinked the layers for the 3D views, so different layers are appearing in different 3D Views. To re-link them make sure the Lock camera and layers button is checked in the header of the 3D View:

You also have your objects on different layers, so upon enabling Lock camera and layers, one or more of your objects may disappear as the other 3D views will now only be displaying a single layer. The 20 squares, arranged in a grid, to the left of the red box in the screenshot are your layers. You can move objects between layers by selecting an object, pressing M and selecting a layer or view different layers by clicking one of the squares.

See the Layers section of the Blender Manual for more information on managing and viewing layers.


You can create this shape relatively easily using CtrlShiftB to Bevel Vertices with 2 segments:


How Do You Stack Instances on Z axis with Animation Nodes 2.0?

The Distribute Matrices Node allows you to do exactly what you want:


How to make the camera move with the object while animating

A camera in the real world rarely tracks directly onto the subject - it will typically lag behind the motion of the subject so that the faster the subject moves, the further the camera will become out of position before it can catch up and the nearer to the edge of the frame it will be. We can emulate this effect by tracking the camera to Empties that follow behind the object rather than to the object itself.

Add two Empties to the scene - one will be the point the camera is pointing at (target), the other will be the 'ideal' position of the camera (goal). The 'goal' can be parented to the object so that it stays at a fixed position in relation to the object being tracked - in this way the camera can be made to follow the object at a fixed distance and direction. A Track To constraint on the camera will point it at the 'target' Empty.

Drivers will be used to re-position the camera and the 'target' on each frame.

To achieve this, select the 'target' Empty, right-click one of the Location fields in the properties panel (N) and select 'Add Drivers'. Open a Graph Editor window and change the mode to 'Drivers' - you should see the three drivers for the X, Y, Z location. For the X Location, the default 'var' variable should already default and set to Transform Channel for X Location - set the 'Object' to the object being tracked. Create a second variable named 'self' and similarly set to Transform Channel and X Location - set its 'Object' to the 'target' Empty. Set the driver expression to '(var + self * 4)/5.

NOTE : To enable driver expressions you may need to go into File/User Preferences/File and enable Auto Run Python Scripts.

Repeat for each of the Y and Z locations, changing the Transform Channel to the relevant channel in each case (ie, Y Location for 'Y' and Z Location for 'Z').

The expression (var + self * 4)/5 calculates a point that is 1/5th of the way between the Empty and the object being tracked and the Empty will now move to that calculated position on each frame. This will mean that the Empty will gradually move towards the object being tracked and will lag behind the object as the object moves.

Moving the object using keyframes should now result in the camera tracking to the object with a slight lag when you run the animation. The lag will be greater the faster the object is moving.

Set up similar drivers for the Camera (ie, select Camera, right-click a Location property, Add Drivers, go into the Graph editor and set up the drivers with Object set to the 'goal' empty (var) and the Camera (self)).

To increase the lag in the calculated postions you can adjust the calculation - for example '(var + self * 9)/10' will move it 1/10th of the distance, '(var + self * 19)/20' would move it 1/20th of the distance - so it would take much longer to reach the goal.

If you now run the animation you should find that the camera attempts to move with the tracked object and attempts to keep it in the centre of the shot.

NOTE : As the object positions are calculated 'on-the-fly' you can get unexpected results if the frame number jumps forward/backward or blender calculates sub-frames (as the calculated positions will still move as if a single frame has advanced). Therefore, it's a good idea to Bake the animation prior to rendering by selecting each of the 'dynamic' objects in turn (ie, the 'target' Empty and the Camera) and go to Object/Animation/Bake Action in the 3d-view menu. Once baked to keyframes you should disable the drivers by clicking the image of a speaker in the Drivers view.

Blend file attached


How to make a hair look normal or not blocky

Below is an image of how I connected the maps for just the hair. I'm sure you figured out by now (It took me a minute) that the suffix letter to the map name refers to what kind of map it is (Ex: M = Metallic, N = Normal, C = Color, and A = Alpha). What threw me for a second is that unlike common setups which have the alpha as a built-in component of the basecolor map, this one uses a separate map, using the color, not the alpha value. See below:

Also - note the blend modes I highlighted on the right side. You can play with them to your liking, just don't pick opaque - that will leave things opaque and "blocky" as you said.
NOTE -  I just noticed, in the image I provided, the metallic map is set to sRGB color space, this should be non-color.
Hope this helps


How To Resize a Node Using Python script

According to the API, there is Node.height as well as Node.width. Assign whatever float you like:

  Type:  float in [-inf, inf], default 0.0

API link: https://docs.blender.org/api/current/bpy.types.Node.html


How to make a curve behave like a squeezed tooth paste (to born from a moving object but to stay on ground)

Wow, found a wonderful method.
You see, you can add a curve modifier to a curve, who knew!? :)

I made a CURVE profile to the ground that should be followed
Then I added the CURVE_toothpaste that is the shape of toothpaste coming out of tube and put a curve modifier to it, so that it follows the PROFILE
Then I animated the location of the CURVE_toothpaste
And also animated the location of the toothpaste_squeezer that followed the profile curve (note that the animation happens on the curve, not on the squeezer)

See the .blend for clarification

.Blend here:


Copy a node-based material to another object, and then freely edit the second one?

This probably has already been solved by the OP, but I came across this problem myself and searching for an answer I stumbled upon this post.

And for the sake of those eventually looking to solve the same problem, I'd like to add an important detail:

The answer given by Duarte Farrajota Ramos is correct, yet the OP said he was still having trouble, and in fact so did I after following his instructions (in fact I was already doing all that he said even before seeing his answer, and it wasn't working), the problem here is the nested/grouped nodes inside the material, they have defined users as well, and if you just make the main material (in the material tab) single-user, the alterations you make on the first level of nodes in fact won't be passed on to the original materials, but if you alter the inner layers, I mean, alter things inside the groups that compose the material, it WILL change the original material you used as a base. Note, this will happen even if you create a material from scratch and copy/paste the nodes from another material, cause the data of the inner groups is still being shared between materials, only the outer layer is in "single user mode".

To solve this, you must simply create the new material, make it single user on the material tab by clicking it's users number (if there is any), this will make the outer node layer single user. Then go in node edit mode, look for the grouped nodes and do the same, you'll see they have their own users number, click on that, and now you can alter whatever you want, and nothing will get out of that material.

Material tab, you can see there are no users, yet I was still getting my base material changed:

Node editor, and here I found the problem, the inner node group was being shared with other 8 materials:

This is indeed some really basic stuff, but for newcomers it might prove to be a challenge, cause it may just pass unnoticed that you must clear the users from all layers. Hope I can help someone. Cheers!


Actually, MakeHuman does include Blender add-ons, such as MakeClothes.  If you download MakeHuman for free, then you can use this add-on in Blender to make clothes off of a MakeHuman base mesh created in the add-on.  You can also use MakeHuman to create the clothes from a library, and expand the selection with free downloads on MakeHuman’s website.


How to fix warped faces when using boolean modifier on curved objects?

First, unless you have good reason to keep it high-poly, I would simplify with a CtrlE > Un-Subdivide:

Then boolean it, give it some corrections like dissolve or merge some vertices, when you're good on a side or on the front, use Symmetrize:

Create a bevel on the joint:

It looks good. If you want a higher poly, subdivide.


Is it possible to dynamically reduce the number particles based on distance from camera?

You can use a script that calculates the distance of each vertex in your grass field from the camera at each frame, and updates a vertex group controlling your particle system's density accordingly.

To get this to work:

Your grass field needs to have a vertex group, with all vertices included (create then select all verts and press "Assign").
In your particle system, you need to set this vertex group as the Density group, with inverted weight (see the image below).
Make sure to replace the names of your grass field object, particle system and vertex group if needed in the script (they're called "Plane", "ParticleSystem" and "Group" in the code below).
Open a text editor window, create a new text file, copy the code there and press "Run Script".

Here's the code:
import bpy

def weight_from_distance( scene ):
    floor = bpy.data.objects['Plane']  # <== REPLACE "Plane" with the name of your grass field object
    cam   = bpy.data.objects['Camera']

    vert_distances = [
        ( cam.location - floor.matrix_world @ v.co ).length for v in floor.data.vertices #Updated for 2.8+: Replaced '*' with '@'
    ]

    maxDist = max( vert_distances )
    minDist = min( vert_distances )

    for i, d in enumerate( vert_distances ):
        # Normalize distance and set as vertex weight
        floor.data.vertices[i].groups[0].weight = ( d - minDist ) / ( maxDist - minDist )

    pSysName      = 'ParticleSystem' # <== REPLACE with the name of your grass' particle system if needed
    vertGroupName = 'Group'          # <== REPLACE with the name of your vertex group if needed

    floor.particle_systems[ pSysName ].vertex_group_density = vertGroupName # Update / Refresh

bpy.app.handlers.frame_change_pre.append( weight_from_distance )


Assigning different wire or halo materials to different parts of a mesh

It's not possible, you can only use a single wire or halo material and this will be applied to the entire mesh.

Part of the reason is that materials are set per face, and wires and halos are for edges and vertices so there is no exact way to map them. But it's mostly just something that was never implemented.


Is it possible add a group to selection (not selection to a group) in the in 3d viewport?

Would it be Shift+G > Select Grouped > Group > Group Name?

After executing the operator, on the bottom of the tools panel or pressing F6 you can open the operator properties and tick the Extend option to extend current selection


Is there a way to fill in hollow objects?

If i understand you, you have the airways components as one object and a cube that you placed around it.

If so, then i would believe all you need to do is the following:

Select the airway components and go in edit mode
Press A to select all elements
Press Alt+N and select "Flip" to flip the normals. (the outsides become the insides and vice versa)
Now go back in object mode and select the cube/block and the airways components
Press Ctrl+J and you will have an object that considers the empty area the inside of the airways components as outside while the area between the outside of the cube/block and the airways components are considered inside and will be filled.
There might be small parts that you will have to adjust, depending on where and how many outlets/openings you need for the airways components. That part should be easy to deal with if you loop cut or inset faces to generate enough vertices to connect the airways components outlets to the outside of the cube. Using "X-Ray" Alt+Z it should look something like this "very" simplified version.

To finish it, make sure to check the "Face Orientation" once more.

The outside of the cube/block should be blue and the connections from outside to the hollow airways components needs to be blue inside of their hollow parts, while if you go through the cube/block with the camera, it should show all red as you would move through the area considered inside the object where the 3D software (slicer) would give you the options to fill.

It's important to make sure that no surface has red and blue colored faces on the same side! But the "Solid" check of the "3D-Print Toolbox" add-on  will test for that.

Happy Blending.


What is this line coming from the light source and how do I adjust it?

That line indicates the direction of a sun lamp.
If you rotate it it will determine the direction for the light and shadows.
Note that for sun lamps the placement in the 3d environment is irrelevant, they just have direction.
To control the size of the line (and it is just an informative line line for you to see the direction) just scale it (press S and drag the mouse)


In my opinion you don't need to bend a mesh to do this. Just use a texture and use the geometry of your object. Avoid overlapping geometry and prevent z-fighting. If you use the texture as a bump map or as a displacement map you can control the indentation or relief (and will help you keep a low vetex count).


Quick Way to Extrude Line to Make Ledges?

Ah ha! Apparently it's called Rip-Fill. Simply select the desired vertices/edges and press Alt+V. And it seems you can pick which side moves by which side the mouse started on when you press Alt+V. Amazing.


Bones not rotating properly in gimbal mode

That red line that shows up when you are rotating means you are locking the rotation to the X axis by pressing X - this will be the world's X axis.

When you first start to rotate by only pressing R the rotation is restricted to the view orientation, meaning it will appear to rotate in a circle as seen in the view you are using.

You can also lock the transform to the objects local X axis by pressing XX.

This can also be adjusted to the Y or Z axis when moving, rotating and scaling. Also to remove an axis from the transform also press Shift. eg pressing S then ShiftX will scale on both Y and Z axes.

You can change the transform orientation used by the widgets in the header menu.

Sometimes you can also find it helpful to use RR which puts you in trackball rotation - that is not locked to any particular axis.


Rigging: Arm moves the pants even though it has no weight

I finnaly figured out how to solve this, i hope this helps someone with the same problem.

what i did was i deleted all vertex groups that corresponded to the upper body inside the pants mesh, if i go to weight mode you can see that its purple because it has no vertex assigned as the arm in the pants mesh. somehow removing weight wasnt working so this was the only way i could solve that.


Constant errors with Rigify (Blender), and ultimately can't import to Unity3D

Go into Blender's User Preferences and on the File menu, tick 'Auto Run Python Scripts' on and regenerate the rig. This will fix half of it missing. However, when you move into Unity, you'll notice that Rigify creates a lot of controllers and widgets, that while very helpful in Blender, are rubbish for Unity. I suggest taking a look at the Rigify to Unity package in the Asset Store as well.


How to compose alpha information on a render result with transparency?

I think the Alpha Over node will do what you want?  Here are some quick results:


Generation has thrown an exception: but there is no exception and it wont generate the rig correctly. how do I fix this?

You can try to clean the file you're working on, going in the outliner, changing it from "view layer" to "orphan data" and click the "purge" button many times, until only brushes remain, then generate.
Try also the advanced options, choosing to generate a new rig with a new rig name, instead of overwriting the previous rig.
Try also to append the metarig into a new file and generate from there.
If the problem persist, please upload your file.


Problems with hard cutting videos when using different frame rates and speed control

I strongly suspect this is a bit of a duplicate question, even though it isn't terribly clear to a cursory examination. That is, I have a hunch that your image and / or video is compressed using a relatively highly compressed codec. When this happens, especially with long Group Of Pictures codecs (long GOP), you can expect that your hard cuts will not be able to be maintained because you will likely have cut in the middle of one of these GOP runs. When this happens, your video is unable to properly sync because the precise frame cut position has happened in a place that is unrecoverable, and as a result the codec decoder must resume from the previous "whole" frame.

While this might not be apparent immediately, similar sorts of issues crop up with heavily compressed audio and the result is very similar.

So how to resolve this? Convert your entire stream or streams to a native image format or AVI JPG series, and audio to WAV format.

Why does this solve the issue? Because then, wherever you place a cut, the image and audio have an immediate ability to be resumed at wherever the cut point ends up, without requiring a "rewinding", which is causing the issue.

While I am not 100% certain, I would wager that there is a greater than 50% chance this is your issue. If it turns out to be the case, there are other folks that are vastly more capable at finding the duplicates and citing them here.


If you mix a diffuse and transparent shader together you can animate the mix value so that the material goes from visible to invisible. Mouse over the mix value and press the I key to create a Keyframe, move to the frame where you want the text to be completely invisible and press the I key again .


"Follow curve" throws my objects chaotically

While I was typing this question, I figured out the answer. I needed to set the origin of my object to match the origin of my path.


I found the problem. I have previously made a animation out of images in sequence editor. When I clicked render, the computer did not do any rendering, it simply loaded already rendered image.

I fixed this simply deleting all the time strips @ Video Sequence Editor. Now it does surely take up to 5 minutes for one frame to render. :)

Cheers for all the help!


Metallic, reflective material not displaying reflections of the World HDRi on EEVEE, how do I fix it?

I just checked out your .blend file. You don't need an irradiance volume or a reflection sphere to reflect the HDRI - in fact, in this case, it is messing with it. Irradiance volume only captures indirect light, and reflection sphere helps with SCENE reflections - but is not needed for WORLD reflections. It works if you delete them, and then delete the lighting cache - see below:

If you want to see more of the world reflected, I would also suggest you lower your roughness a bit, but that's up to you and what you want to use it for.
Cheers


What is the Python script to create nodes?

Here is a repo that does exactly what you want. It has a ready-to-run python script that can be run from the command line in the background without opening the blender GUI. It creates a water material on a surface mesh for a convecting bubble - this is done with 2 different shaders and mixing them using a mixer shader. The script loops through the different files and renders the images as jpeg. The images are also there in the repo. Just clone the repo and run the command given in the README file in the terminal. This scripting was done with Blender v2.78.

https://github.com/nataraj2/BlenderScripting


How do I do a video glitch with wrap around edges?

You can achieve this effect with the Displace node (for distortion) and the Translate node (for wrap around).

Create a texture for the desired skew or offset effect, then send this to the X value of the Displace Node.

Use a Combine RGB node to send a large Value to the Red or Vector X input. The Combine RGB node doesn't allow you to enter a value over 1 unless you type it in. I have added a Value node (the Green node) to make this easier. You animate the amount of distortion with this node.

The Red curve node allows you to modify the nature of the distortion, by modifying the contrast of the texture you can make a pointy effect or a rounded effect.

In this image you can see that the right edge the image is wrapping around to fill the gap left by the distortion. I have piped the Value node into the x axis of a translate node, then combined it with an Alpha Over onto the distorted offset image.

If I invert the texture then the distortion will affect less of the image.


Note: I've used method from here: How to save curve shape of cylinder with
  such deform? with Shrinkwrap modifier to place vertices in oval
  shape without distorting overall mesh shape.

I think topology from below image is probably the cleanest possible. It allows to add Edge Loops to control hardness to the edges of indentation or you can use Mean Crease there.

I've made indentation by pushing vertices with Proportional Editing enabled.


Speed up Trigger/Delay Actions Workflow in Animation Nodes

Your animations are already described parametrically so you needn't bake anything. Simply define a function that takes the time as input and outputs the required mesh. Then loop over your instances transformations and evaluate the function you created. A simple example would be as follows:

Which results:


How do I prevent a texture from stretching when using a boolean modifier on the object?

If using generated texture coordinates, such as:

The coordinates will be between 0 and 1, whatever the object size is.

So if we apply a boolean, the resulting object size changes and the texture stretches (which can be an interesting effect, by the way):

If we use 'object', like here:

Coordinates are stable in object space as they are the real coordinates, not remapped between 0 and 1.

So:


What are the minimum spec requirements for 2.8?

As you said it, Eevee is a GPU Boosted engine, it uses features present in >= OpenGL3.3. The fact that you added Substance made it suspicious for a driver issue.  Make sure you have DirectX and .NET for Substance and the latest OpenGL Drivers.

As for your other question, new cards are  mostly OpenGL 4.5 capable. You can check your OpenGL version by going to the dxdiag. And please add more details about your PC specs, it helps us better


You certainly can Shade Smooth Curve.

In the Transform panel ("T" menu).
Curve Data tab under Active Spline.

If it is not working as it supposed for you, probably you have some issues with your Curves.


There is no built in functionality for this. However, you might be able to achieve what you want using drivers. Use the Render resolution as the variable. Perhaps you could define a custom property for the total blur value?


Blender modeling materials in Unreal Engine 4

Sorry it's a bit hard to tell, but are you talking about placing Materials in Material Slots? If so, you can do it through the Material Properties Tab:


Render an animation with 2 different cameras but at the same time

Copy your scene and render both scenes. To do so go to the top of your window and click the + next to your scene and choose Link Objects.

Next select the inactive camera and make it active.

Then go to compositing and check Use Nodes. Now delete the Composite node and add another Render Layer node (Add > Input > Render Layer).

Select the newly created scene in the new Render Layer node.

Now add two File Output nodes (Add > Output > File Output), and input each of the renderlayer nodes into an output node.

Lastly, in each of the output nodes, navigate to the paths that you want each camera location to be saved to. But be careful not to choose the same path for both nodes, because one output will overwrite the other.

All that's left is to hit render animation and watch the magic happen.


Rip secret door, showing no trace of edges, into shade smooth sphere

As @Hikariztw has suggested, you need to give the cut sphere some custom normals.

On the cut sphere, check 'Auto Smooth' in its Data tab > 'Normals' panel, to enable vertex-per-face normals
Retain an intact copy of the sphere, in exactly the same place as the cut one. You can M,move that to another collection, and hide it, to avoid confusion. I've called mine 'Form'.
Give the cut sphere a Data Transfer modifier, settings as shown, to copy the normals from the intact sphere to the cut one.

You can apply the modifier, and dispose of the intact sphere to tidy up, if you like.

EDIT: in 2.8, you can evaluate the normals in Object space by unchecking the little collection icon at the right of the 'Source Object' field. That way, the target 'Form' does not have to be in exactly the same location or orientation as the cut sphere.. you can just shove it off to one side.


why are my cones upside down using the blender api?

Code re-jig.

Don't think deletion is required, will however run thru an alternative route or in other terms FWIW:  "How I would go about it".  BTW also really appreciate questions like this one where the OP has had a red hot go at creating a script. Please take this in the spirit of offering an alternate way
Some tips.

Use Vector math. There is never a reason to include the Euclidean distance formula when dealing with vectors.  It is the vector length. Rarely do we need to split the vectors component wise. For example the 6 components passed to the create support method, should it be the case that x2, y2, z2 is not on vertical line then q code would not create an angled strut in any case.

Multiplying local coordinates by the matrix world of their object will put them into global space, which allow for all transforms including scale.

Avoid edit mode toggling. Here I've created the struts using lower level bmesh operators, enabling no edit mode toggling.  Could also consider making a support only once and copying and scaling when more are required.

Test code.
import bpy
import bmesh
from mathutils import Vector, Matrix

from bpy import context

ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)
mw = ob.matrix_world
coll = context.collection

strut_radius = 0.1
cone_radius = 0.4

coords = (mw @ f.calc_center_median() for f in bm.faces if f.select)
bm = bmesh.new()
for co in coords:
    bm.clear()
    cone_mesh = bpy.data.meshes.new("Cone")
    bmesh.ops.create_cone(
            bm,
            segments=16,
            diameter1=cone_radius,
            depth=co.z / 10,
            cap_ends=True,
            cap_tris=True, # tri fan fill.
            matrix=Matrix.Translation((0, 0, co.z / 20))
            )
    bm.to_mesh(cone_mesh)
    cone = bpy.data.objects.new("Cone", cone_mesh)
    cone.location = (co.x, co.y, 0)
    coll.objects.link(cone)

    bm.clear()
    strut_mesh = bpy.data.meshes.new("Strut")

    bmesh.ops.create_cone(
            bm,
            segments=3,
            diameter1=strut_radius,
            diameter2=strut_radius,
            depth=co.z,
            cap_ends=True,
            matrix=Matrix.Translation((0, 0, co.z / 2)),
            )
    bm.to_mesh(strut_mesh)
    strut = bpy.data.objects.new("Strut", strut_mesh)
    strut.location = (co.x, co.y, 0)
    coll.objects.link(strut)


How can I make it so only one object in a group is visible at a time?

This behavior can't be accomplished in current Blender versions through standard UI/ Tools. Something like this has yet to be written for Blender.

(Edited for being to vague.)


How do I make a large set of objects appear over a period of time?

Keyframes or Drivers on hide and hide_render

I would suggest either creating ether a keyframed action, or setting up drivers on the hide and hide_render properties of your object.

How you convert from your time to frames is up to you. In bpy.utils there is a convenience method that converts a datetime object to a frame.

Drivers

Each object from data will be hidden (both in viewer and to render) until the scene frame is greater than the data frame. Test script below.

import bpy

context = bpy.context
scene = context.scene

data = [[0, 0, 1, 12],
        [0, 10, 3, 30],
        [3, 3, 4, 40],]

for line in data:
    x, y, scale, frame = line
    bpy.ops.mesh.primitive_uv_sphere_add(
            location=(x, y, 0))
    ob = context.active_object
    # set scale
    ob.scale *= scale
    # add drivers
    for dp in ["hide", "hide_render"]: # xxx
        driver = ob.driver_add(dp)
        driver.driver.expression = "frame < %f" % frame

Keyframes

Keyframe as hidden at frame 1, show at data frame.

    # add keyframes
    for dp in ["hide", "hide_render"]: # xxx
        setattr(ob, dp, 1)
        ob.keyframe_insert(dp, frame=0)
        setattr(ob, dp, 0)
        ob.keyframe_insert(dp, frame=frame)


One way to do this is with a curves addon.

Go to the user preferences by pressing CtrlAltU. Under Addons type "extra" into the search field. Enable the checkbox of "Add Curve: Extra Objects".
This will give you some additional options to create curves.

Now go back to the 3D view and press ShiftA to add a new object and select Curve->Spirals.

In the Tools shelf (the menu on the left of the 3D view that is toggled by pressing T) settings for the spiral will appear. Play around with them until you are satisfied with the shape of the spiral. You probably want a spiral of type 1 or 2 and a "Curve Type" of 1 (for smoothness).

To give the spiral some thickness you will have to add a taper object to the curve. Go to a new layer and add a Bezier Curve. The distance of the curve from its object origin will represent the thickness of you spiral along its length. For a linarly increasing thickness edit the curve to look something like this:

The shape around the spiral is determied by a bevel object. Just add a "Circle" curve. It does not matter if it is a Bezier Circle (just called Circle in the menu) or a Nurbs Circle.

Go back to the layer with the spiral and select the spiral. Go to the curve settings and select the bezier curve from the other layer as "Taper Object" and the circle as "Bevel Object".

The result should look like this:

You can play around with the shape of the taper and bevel object to achieve diffent effects. To close the end of the spiral you can also enable "Fill Caps".


Does anybody know how to paint multiple meshes using scripts?

Can set the material directly with obj.active_material.  The material index will be obj.active_material_index.  The material can be set directly to the faces with face.material_index.  Note I've used the scene.objects collection, and only looked at mesh type objects.

Test code below.

Textures fine, commented out re filename.

import bpy

context = bpy.context
scene = context.scene
#  reuse Red material
mat = bpy.data.materials.get("Red")
if mat is None:
    # create
    mat = bpy.data.materials.new(name="Red")
    mat.diffuse_color = (1, 0, 0)
    #tex = bpy.data.textures.new("red", 'IMAGE')
    #img = bpy.data.images.load("D:\\red.png")
    #tex.image = img
    #slot = mat.texture_slots.add()

mesh_objs = [o for o in scene.objects if o.type == 'MESH']

for mesh_obj in mesh_objs:
    mesh_obj.active_material = mat
    mesh = mesh_obj.data
    for face in mesh.polygons:
        face.material_index = mesh_obj.active_material_index


how do I bring back the initial menu to configure a mesh?

The math function menu like all object initialization menus can only be used when you create an object, if you go to edit mode or use any operation in the 3D view port, it will disappear.


How do you make it a new object after extruding?

Select the new faces you've created, hit P, then Selected and tap Tab to get out of Edit Mode. You'll be able to select the faces as another object now (its good to hit Ctrl+N on *Edit Mode inside the new object to correct the normals too)


Strange black lines in import of FBX file from Maya 2014

Those lines indicate a parent-child relationship.
It's actually a good thing, because it means the hierarchy of your model will still work in Blender! :)

If you find these lines annoying, open up the properties sidebar of the 3D Viewport by hitting N, open up the Display Panel and disable "Relationship Lines".


How to Keep Textures High-Res Without Scaling UVs Ridiculously

Instead of directly connecting the UV Vector output from the UV Map node to the image input in the material nodes, insert a Vector > Mapping node. You can use it's scale component to scale the existing UVs, or move/rotate them.

For scaling only a Vector Math node set to multiply will do just as well.

This will obviously not work in an exported object for another program without corresponding material nodes.


Texture appearing in squares across the map

I would start by looking at your UV map. If you try using the color grid or UV preset textures (when you create a new texture) you should be able to see if your UV map makes sense, or if it's causing the issue.

If the UV map is the problem, you can probably just UV unwrap your object again. To make a flat UV map from above your object (which should work for your terrain), switch to edit mode with Tab, toggle to orthographic view with Ctrl+5, switch to top view with Ctrl+7,  then select UV unwrap (or press U) > Project from View (Bounds).


how to speed up viewport FPS to play in realtime?

This question have been asked already but it's a bit old so I will sum up the things with Blender 2.8 in mind:

In User Preferences > Viewport tab

Disable anti-aliasings and multisamplings (you can keep the smooth wires in edit-mode though, if you don't try to playback in edit-mode).

In your viewport

Disable anything you don't need on playback. May it be objects that are not critical, collections, shadings, ... And disable the overlays (or at least the outline selected which is the heaviest by far).

Modifiers

If there are some you don't need, hide them.
Use the Simplify Panel in your render settings to lower your subdivisions, particles display and textures loads.

Physics

Unless they are critical to your animation preview, don't even load them in your scene (this if where having scene parts in different .blend files to link in a final .blend file is powerful). I think in 2.8 if you uncheck a collection, under the hood it's like not having it in the file, so maybe use that.
If you do need some form of physics, first make sure to use low quality preview settings if possible, and bake everything on your disk so it doesn't have to update all the time.

Animation editors

May it be the dope sheet, graph, timeline, ... They all eat a lot of resources when animating anything more complicated than a bouncing ball. So make sure to hide anything you can.
Use the filters to hide what's not selected or hidden, and what things you don't need to see there ever:


Is it possible to change the default transparent color when texture painting?

In your material settings for your image texture - the material in the Shading tab of the properties panel needs to have Z Transparency turned on for the GLSL viewport to allow you to 'see' the erase alpha as the background showing through.


Instant Remesh Blender add-on error in blender 2.91

Under this addon's settings when you first select the Instant Meshes Executable it uses a relative path. Manually set the full path to the EXE.


Why does my blender file close a few seconds after opening it and how do I fix this?

This may be caused by any single object in your file. Try opening a new project, click File -> Append, and add the objects from your corrupt file chunk by chunk or piece by piece. This way you can narrow down, if or which single object causes Blender to crash.


Can symmetrize by used with the multires modifier?

Yes, you can use the edit-mode Symmetrize tool.

  EditMode -> Mesh (Menu) -> Symmetrize

Note, there was a bug with Multi-res modifier which is now fixed in daily builds and will be included in the 2.77 release (commit).


When I add a subdivision modifier and smooth my model I get artifacts. Modeling a human head. Blender 2.80

moonboots answered my question correctly. Shift + N is the "Make Normals Consistent" shortcut.

Blender 2.80 Normals documentation: Normals

Here is the "fixed" model after implementing the fix:

Thanks for the help, @moonbots!


Is it possible to use a texture to control the size of particles?

Just add a texture to your emitter and in the influence panel of the texture choose Size for emitter particles or Length for hair particles.


With image packaged into blend it works for me as expected. The issue appears when TIFF is unpacked and used linked from directory. Troy_s probably will be able to explain the issue, I don't have a knowledge in this area. I can just say how to avoid the issue here.

your TIFF doesn't use Transparency but channel "Alpha" (that is also why option "Save Transparency" is grey when you are saving your TIFF

to avoid the issue copy alpha channel and paste into Mask channel for "Background" layer.

Then when you save with "Layers", "Save Transparency" is available.

This TIFF is rendered fine in Blender.


Mesh disappears when Soft Body physics enabled

This is easy to replicate by simple adding Suzanne to the scene, enabling Soft Body and enabling Self Collision - and the issue seems to be specific to Suzanne (the other primitives don't exhibit the problem). You can tell something is very wrong by checking the Dimension of the mesh (in the Properties panel (N)) on the second frame - it jumps immediately to some very high values :

The problem appears to be due to the geometry of the mesh - specifically Suzanne's eyes. The eyes are not connected to the rest of the mesh and actually overlap. This is resulting in particularly odd results with the self-collision - presumably as the overlapping vertices repel each other with almost infinite force.

To avoid the problem, in Edit mode (Tab) click a vertex on one of the eyes, hold Control and press Numpad + a few times until the whole eye is selected. Move the eye away from the head. Repeat for the other eye - so that both eyes are no longer overlapping the head.

Now run the simulation and it should behave normally.

I got some interesting results by just moving the eyes a little way away from their original locations. This, presumably reduced the repulsion forces to much smaller values, while still being too close for a stable simulation, resulting in Suzanne being pulled apart rather than being completely obliterated (I think the eyes are being repelled backwards at high speed through her head while the head is being launched forwards) :

So, in summary, the problem is due to overlapping geometry/vertices. Fix the geometry to avoid such problems.


In a regular triangulation of a regular quad topology, vertices connect six edges, and its Dual is a hexagonal mesh..

So as @Leander has hinted in the commentary ..

Install the shipped 'Tissue' Add-on
CtrlT or use the modifier to triangulate the mesh
Use one of the Add-on's 'Dual' operations.

The regions of the mesh which were quad grids will become hexagonal grids.


If you store the list of indices in a list object (array), it will be accessible even after the object is no longer in edit mode.

import bpy, bmesh

o = bpy.context.object

# Create bmesh object. This particular method requires that the object will be in edit mode.
bm = bmesh.from_edit_mesh( o.data )

# Store list of selected face indices in object (will be empty if not face is selected)
selected_faces_list = [ f.index for f in bm.faces if f.select ]

# Go to object mode
bpy.ops.object.mode_set( mode = 'OBJECT' )

# Print content of list to show that it still contains face indices although we are now in object mode
print( selected_faces_list )


How to slide one object on another, keeping curvature?

If I were you I would probably create a curve that matches the curve of the character, then use a curve modifier on the glasses.

If you don't want the goggles to distort, then you could parent the goggles to the path then you can move along the path by changing the frame (left/right arrows on your keyboard). That doesn't work if you are also animating the character though.


Blender is primarily a polygon based modelling tool. Curves have received some attention over the years and are quite acceptable as modelling devices now. However Lofting, which creates surfaces from Curves (or potentially NURBS) is, if we are honest, a little bit of a Fiasco, still in 2015. Those of us who want that functionality seem to be in quite a minority, else it stands to reason that these features would be much better supported.

The power of the Bridge Tool and the CurveTools addon shouldn't be underestimated. From what I can tell CurveTools is still semi-actively under development.

Your question is, "how would you loft between curves"? I use Sverchok (Node based geometry addon for Blender).

While the example image shows three splines which are part of the one curve, this is to illustrate only the control points of the splines. For this to work in Sverchok you

have any number of separate curves
their names are important for sorting
the origin of all the curves should be the same, the geometry of the curves themselves is of course entirely up to you.
with the curves selected, press the Get Selection button on the Objects-in node , and hook up  the nodes something like the image shows.

For live updates you need to scrub the timeline or have it playing, it's a bit of a hack.. but it gets the job done.


Copy an object, but have unique material using python

Because you are copying one object, all the object data is the same. Because of that you can not add different materials to the object data (there is only one). Instead you will need to assign the material to the object, not the objects data.

These five lines below are what create a material, add it to the object and set the link to object, instead of the default object data. The diffuse_color = [R, G, B] is where you specify the color you would like that material to have (blender is expecting value between 0.0 and 1.0 for each color channel). Keep in mine this code is only for cycles, the blender internal render has a different way of doing materials.

mat = bpy.data.materials.new("materialName")
mat.diffuse_color = [R, G, B]
ob.active_material = mat
ob.material_slots[0].link = 'OBJECT'
ob.material_slots[0].material = mat

Full edited code below.

import bpy

bpy.ops.object.select_all(action='DESELECT')
bpy.ops.mesh.primitive_uv_sphere_add()
sphere = bpy.context.object

R,G,B = 1,0,0

for i in range(-1000, 1000, 2):
    ob = sphere.copy()
    ob.location.y = i
    bpy.context.scene.objects.link(ob)

    mat = bpy.data.materials.new("materialName")
    mat.diffuse_color = [R, G, B]
    ob.active_material = mat
    ob.material_slots[0].link = 'OBJECT'
    ob.material_slots[0].material = mat

bpy.context.scene.update() # version < 2.8
# bpy.context.view_layer.update() # version 2.8


Is there an Attach Option in Blender for Splines?

The right term in Blender is Join. Select all your curves, then Object/Join.

In the Curve panel, make sure your curve is set to "2D", so the inner shapes can be subtracted from the outer shape.


How do I apply color with Cycles Material Nodes with No UV?

Nodes using Generated Coordinates

No UV

Nodes Use Generated X Coordinates.  Image above.    Cleanup Pending. We think these are better attached to vertices and survive rotation as the image shows a translated and rotated lemon. See axis orientation.  Please test and confirm.  Artistry not considered.

Please improve these nodes.

Deprecated Nodes of Lemon Quality abusing the X position of fragment.

Cycles Render.  Less Green.  X Coordinate used. Object Centered at Origin.  Image Above.  Keeping some old nodes until cleanup.

More Green.  Nodes showing use of X Coordinate.  Left and Right value made equal via Absolute Value Node.

The Multiplication node controls the spread.  Its value is keyframed.

Do not eat lemons like this.


Retain circular shape after adding subdivisions with sub surf mod applied

If I understand well, your issue is to recalculate edges/vertices to be circle shape after adding more cuts, maybe this answer could help.
Anyway if that the case, you should first outline well your circle mesh using as less as possible edges, or add circle mesh instead outlining it by hand.


How to export vertices' locations in a .dat file?

Animation Nodes
You can use Animation Nodes to get such information and write it to a file. First, loop over the polygon indices and get the vertices locations at those indices, then get the individual numbers of the vectors, convert them to text and join them using as space as a separator:

Then join the output using a linear break as a separator:

Then you can write the text to a text block using the Text Block Writer Node:

Save the text and you are done.
Python
This script will write the data to the text block test.dat:
import bpy

mesh = bpy.data.objects['Icosphere'].data
data = ""

for poly in mesh.polygons:
    for vert in poly.vertices:
        for c in mesh.vertices[vert].co:
            data += str(c) + " "
    data += "\n"

if not "test.dat" in bpy.data.texts:
    bpy.data.texts.new("test.dat")

bpy.data.texts['test.dat'].write(data)


How to make a curve smooth in the Graph Editor when you restrict the frames of the noise modifier

In the noise modifier you can try to use the ease out option of the frame range restriction, that should blend between the noise and the rest of the animation (the value is the number of frames of the transition).
If this does not solve the problem you should upload the file.


Warp image to fit UV unwrap, without using projection unwrapping

In the end, I resulted to keep the same texture as it is and not warp it. Then I experimented around a bit until I found my solution.

First of all, I increased the resolution from 900px to 2048px - this will allow more pixels on steep gradients, reducing the stretch.
Next, when creating my normal map, I set the blur to -10 to make the normal have a gradual change, to create more of a rounded impression than a square-shaped dent.

Following these steps will get you the desired result.


How to curve the mesh without using bezier?

Various Features you can explore

Proportional Edit with a suitable vertex density so there are more vertices to bend
Use a portion of a torus
Use a portion of Cylinder with Solidify Modifier
Curve Modifier and apply on top portion first and isolated
Link to Tutorial https://www.youtube.com/watch?v=MrNVVHdKd3E


Editing fcurve.keyframe points in FAST mode?

This answer doesn't address the FAST mode issue, it is another method to clear an fcurve and set new points that avoids looping, reversing or using  either the insert or remove methods of FCurve.keyframe_points entirely.

import bpy
frames = [1, 9, 20]
samples = [0, 8, 0]
# some action
a = bpy.data.actions["SomeAction"]
fc = a.fcurves[0] # some fcurve
dp, i = fc.data_path, fc.array_index
# clear the fcurve by removing it
a.fcurves.remove(fc)
# new one
fc = a.fcurves.new(dp, index=i)
# new points
fc.keyframe_points.add(count=len(frames))
# populate points
fc.keyframe_points.foreach_set("co", [x for co in zip(frames, samples) for x in co])
# update
fc.update()


Trying to replicate the Blender Cloud dog

Sub-D box modeling

Dixey has a smooth surface with nice curves.

Easiest way comes into my mind is to block out the overall shape and use the subdivision surface modifier to smooth the blocks. Make sure to use the Catmull-Clark algorithm.

Onece built the base mesh, it should be just a matter of refining the shape with more loopcuts, or you can even apply the modifies and use the sculpting tools to increase the bumpiness of certain ares.

Here's a possible result:

Notice how few polygons are used to control the surface.

Other possible techniques to built a base mesh to work with:

metaballs
skin modifer


Blender Sequencer speed is Extremely slow

Keep UI

render with "Keep UI" option in the Render properties panel under Display
(Just don't let blender display the rendering process in any window.) That was a noticeable speed up for me.

Multicore rendering

use one of the available scripts for multi-core rendering. Basically a script that opens as many instances of Blender as you have cpu cores or as many as you specify.
(Blender use for VSE render only one core of CPU by default. So even with a two core processor you get only half the render time. If you have an 8core CPU it would be great speed boost for you.)

Parallel Render - Addon, simple to use, but it generates separate movie files - one for each blender instance (that runs on each core separately).
After download, installation, enable ... you run this script with SPACEBAR search, type "parallel ..."

￼

video_editor_render_script - A python script whit it you need to arrange a few things first, but then it's a ONE-CLICK option with one animation file.
(Namely -download also ffmpeg and specify paths to blender and to ffmpeg in the script. Just follow instructions. In general it also generates separate files for each core first, but than use ffmpeg to merge them in one file.)


Having rigid bodies sliding off an animated object

Yes, this is quite possible.

Simply make your animated object a passive rigid body with Animated enabled:

Then make the objects you want to slide around into Active rigid bodies.

Result:


How to undo clipping vertices by applied mirror modifier

Unless you're talking about cancelling the clipping in the modifier while having it active (There 's a button for it in the Modifiers Tab --> Mirror Modifier --> Clipping), one option could be selecting the mesh that you want to be separated and then pressing: P --> Separate By --> Material (for example). Hopefully this useful in some manner :)


You need to check 2 things: The keyframes of your IK controller bone, and the Influence value of the IK bone.

First enable the Only Include Channels Relating to Selected Objects button (arrow icon). It will allow you, in the Dopesheet, to only display the keyframes of the selected bones.
Now select the controller bone and switch from an action to another, you'll see that sometimes the controller doesn't have any keyframe at the beginning of the action, which means that, until the next keyframe, the controller will keep the position that it got at the end of the previous action, is it what you want?
Also, you'll see that for some animations you have keyframed the Influence value of the Ik bone, so for some animations it will be at 0 and the IK won't work anymore, and will remain off if you switch to another action that has no keyframe for this value, again if there is no new value keyframed at the beginning only the previous one from the previous animation will be taken into account. Again, is it what you want?

So to fix both these 2 problems you may need to create some keyframes at the beginning of the action: Keyframes for your controller and/or IK Influence value.


Perform multiple face transform using individual axis

Change the Pivot center to individual origins, and change the transformation orientation to normal. If you press S for scale and X twice then you are able to do the transformation


Adding a Bezier Curve with a single point at 3D cursor [beginner]

Trying to run it here I got a bad identation error on line 52 in register().

Fixing that I could install the addon, then it complained about

Traceback (most recent call last):
  File "D:\Duarte\System\Blender\2.78\scripts\modules\addon_utils.py", line 349, in enable
    mod.register()
  File "D:\Duarte\System\Blender\2.78\scripts\addons\SinglePointCurve.py", line 44, in register
    bpy.utils.register_class(HalfBoolMirror)
RuntimeError: Error: Registering operator class: 'HalfBoolMirror', invalid bl_idname 'single.point.curve', must contain 1 '.' character

Apparently your bl_idname = "single.point.curve" on line 10 can only have one one "." period character in its name.

Changing it to bl_idname = "singlepoint.curve" seemd to fix the problem and the script installed fine, though I could not see it anywhere in the UI.

This is my final result

bl_info = {
    "name": "Single Point Curve",
    "category": "Object",
}

import bpy

class HalfBoolMirror(bpy.types.Operator):
    """Single Point Curve"""      # blender will use this as a tooltip for menu items and buttons.
    bl_idname = "singlepoint.curve"        # unique identifier for buttons and menu items to reference.
    bl_label = "Single Point Curve"         # display name in the interface.
    bl_options = {'REGISTER', 'UNDO'}  # enable undo for the operator.

    def execute(self, context):        # execute() is called by blender when running the operator.

        # The original script

        bpy.ops.curve.primitive_bezier_curve_add(view_align=False, enter_editmode=True, location=bpy.context.scene.cursor_location, layers=(True, True, True, True, True, True, True, True, True, True, True, True, True, True, True, True, True, True, True, True))

        bpy.ops.curve.handle_type_set(type='VECTOR')

        bpy.context.object.data.show_handles = False

        bpy.context.object.data.show_normal_face = False

        bpy.ops.curve.de_select_last()

        bpy.ops.curve.delete(type='VERT')

        bpy.ops.curve.select_all(action='TOGGLE')

        for area in bpy.context.screen.areas:
            if area.type == 'VIEW_3D':
                ctx = bpy.context.copy()
                ctx['area'] = area
                ctx['region'] = area.regions[-1]
                bpy.ops.view3d.snap_selected_to_cursor(ctx, use_offset=False)
                break

        return {'FINISHED'}            # this lets blender know the operator finished successfully.

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

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

if __name__ == "__main__":
    register()


You can use different material settings in 1 shader and mix them.

Here you have 2 diffuse shaders using different textures. The mix shader uses as factor a random objet info to choose wich one to use. the color ramp, set on constant, allows to use only 1 one them, not a random mix of the 2 (constant) and the Position at 0.5 allows a 50% mix, but you can have more or less of a material moving the slider left or right.


Is there a way to add a specific modifier to more than one object?

As I experiened, the Copy Attributes Menu addon can well support this. You can find Copy Seleced Modifers down the menu, which will only copy sepcific modifier(s) without replacing the original stack. Hope it helps.