How can I prevent blender from doing ridiculously large calculations?

Not in the way you are thinking

This is one of those "Computer Science Traps" that sound easy on paper but are actually impossible for computers to solve.  The specific problem at work is the "Halting Problem".  The gist of the issue:

  the Halting problem is the problem of determining, from a description of an arbitrary computer program and an input, whether the program will finish running or continue to run forever....Alan Turing proved in 1936 that a general algorithm to solve the halting problem for all possible program-input pairs cannot exist.

There are ways to cheat, however.  Firefox, as mentioned above, cheats by putting time-limits ("timeouts") on operations.  Blender does not have this luxury, because, as you said:

  it takes about an hour to bake the increased resolution.

Which, as annoying as it sounds, is still legitimate.

The ways around this to make sure you can see the render/bake output, and check in occasionally.  If you suspect that your machine has bitten off more than you can chew, you can usually escape the process by mashing esc


The answer is: No

You can not directly animate the modifier so that it will be cloth-permeable, but you can easily find ways around it.

I fixed this problem by running a simple small animation myself, a cloth plane falling on a cube with collision settings, and a large plane (with collision settings to act as the floor).

I animated the cube with a LocScale keyframe at frame 1, 50, and 75.

At frame one I added a single keyframe to the cube without doing anything.

At frame 50, I did nothing to the cube, and set another keyframe.

At frame 75, I scaled the cube down to .0001 size, and moved it beneath the plane.

The final result is that the cube shrinks below the cloth, and gives the effect of the object disappearing.

I believe this is the best way to animate these kinds of simulations, so I hope this helps you.

Here is the .blend. (Note: you may need to re-bake the cloth):

Here is a video, too, if you don't want to have to download the .blend.


Those lines that you see are the curve's normals. They can be adjusted, or disabled in the properties panel under Curve Display.


Render Preview is Black but export / render is fine

I've discovered the issue. If someone is facing the same problem, I solved by pressing the pause button at the bottom right of the 3d view window, it only appears when on render preview (shift + z)


cannot export .glb with material setting like specular

glTF 2.0's core material system uses the metallic + roughness PBR system.  You are correct that the specular channel is not currently included.  This may change in a future version of Blender, as there is a newer glTF extension proposal for including it inside of the metal/rough workflow.  But it could be some time before that appears in Blender's importer/exporter for glTF.
In the meantime, for this model you may be able to work around this by setting Roughness to 1.0.  That should make the material diffuse enough to not show any specular reflection.


Changing a value node in many materials with a python script

The script below iterates over all selected objects and adjusts the value nodes in the assigned materials if their label is set to "Scale".
import bpy

def set_scale_nodes_selected_objects(scale_val):
    for obj in bpy.context.selected_objects:
        for mat_slot in obj.material_slots:
            set_scale_nodes_material(mat_slot.material, scale_val)

def set_scale_nodes_material(mat, scale_val):
    if mat is not None and mat.use_nodes and mat.node_tree is not None:
        for node in mat.node_tree.nodes:
            if node.label == "Scale" and node.type == "VALUE":
                node.outputs["Value"].default_value = scale_val

if __name__ == "__main__":
    scale_val = 1.0
    set_scale_nodes_selected_objects(scale_val)


Without seeing a blend file I would guess that the peach_cup_body object does not have the correct material assigned.

There are two materials on the object, one is a cycles material which will render the object as blank when rendering with the internal renderer.

Remove the material called 'material' and your object will definitely be using the 'Material.002' material.

Select the material then press the minus(-) button:


Motion Tracking. What do the graphs represent and how are they useful?

The red and green lines on the graph show you the speed of the trackers at a given frame. Green is vertical movement, Red is horizontal. The red and green curves will always start at zero in the first frame of the scene, and will move away from zero as the tracking points change position on the following frames. Objects closer to camera will move faster than those far away, so the speed in trackers in the foreground will be greater and objects far away will tend to stay closer to zero.
The curves are useful to see if particular trackers are moving differently than the average. A line that spikes way out of the norm might mean a tracking error, like a tracker slipping out of place, or maybe it means that an object is moving differently than the rest, and shouldn't be part of the overall camera solution. You can manually edit the curve by selecting a point in the curve and dragging it or deleting, that will affect the corresponding tracker on that particular frame.
In this example most of the trackers follow the same pattern. The green line that strays from the norm is a tracker that is wandering off. By manually moving the trackers or retracking with different parameters you could get the curve to match with the rest, but in most cases is better to re-track or find a different section of the scene that can yield more accurate tracking.

Once you have done your tracking and hit the camera solve motion button, a bunch of blue lines will appear, They represent the reprojection error for each tracker.

"The reprojection error is a geometric error corresponding to the image distance between a projected point and a measured one" (wikipedia).
Blender wiki says:
"Reprojection error means the average distance between reconstructed 3D position of tracks projected back to footage and original position of tracks. Basically, reprojection error below 0.3 means accurate reprojection, 0.3-3.0 means quite nice solving which still can be used. Values above 3 means some tracks should be tracked more accurately, or that values for focal length or distortion coefficients were set incorrectly."
The blue curves cannot be selected or edited directly on the graph window, but if you select a tracker on the tracking window the corresponding graphic will turn a darker blue, so you can see at what frame the reprojection is failing.
Finding the trackers with the highest reprojection errors is easier on the dopesheet for tracking data. It has a way to sort by Average error and you can see the numbers right next to the trackers name.

Finally, the lonely blue line that comes out when you click on the film strip is the average per frame error.
This curve is available only after pressing camera solve and is not editable.
This is the one line that you want to be as flat as possible and as closer to zero as you can. The high points will show you where in your shot you are having inaccurate tracking.

For general tips on motion tracking please read this post: How can I get better results when doing camera motion tracking?


Complete beginner question, merging vertices

To merge vertices to corresponding vertices on another loop..

Select the sections of the loops you want to merge, (with an equal vertex count)
 and use CtrlE > Bridge Edge Loops, with the 'Merge' option checked in the Tool region, or Options panel in 2.8.

as Ray Mairlot has commented, you may intend to merge vertices at opposite ends of existing edges.. in which case you would AltCtrl select the edge ring, followed by X > Edge Collapse.


Getting weird normal map where mesh is completely flat ( and how to bake normals for unity )

This happens when you have smooth shading turned on on the base mesh. Making it flat shaded or enabling autosmooth should fix the issue.
For the baking on the cube, it's not recommended to have the image you are baking in the material ("Circular dependency for image "image name" from object "object name""), as it uses the old normal map to bake the new one. Try disconnecting it and bake again.


Look like i'm just understand with the concept of loops in blender.

What i'm not aware is one vert can be referenced on more than one loop (and it's pretty common).

So, the solution for this is make sure that the code do not touch the same vertex index (by making a list):

def swapOnAxis (axis):
    C = bpy.context
    o = C.active_object.data
    bm = bmesh.new()
    if C.active_object.mode != 'EDIT':
        bm.from_mesh(o)
    else:
        bm.from_mesh_edit(o)

    uv_layer = None
    if 'SwappedUV' in bm.loops.layers.uv.keys():
        uv_layer = bm.loops.layers.uv['SwappedUV']
    else:
        uv_layer = bm.loops.layers.uv.new('SwappedUV')

    dict = []
    for f in bm.faces:
        for l in f.loops:
            luv = l[uv_layer]
            v = l.vert
            # make sure that we haven't do it on the same vertex
            if (v.index not in dict):
                luv.uv.x, v.co[axis] = v.co[axis], luv.uv.x
                dict.append(v.index)
            else:
                luv.uv.x = v.co[axis]

    if C.active_object.mode != 'EDIT':
        bm.to_mesh(o)
    else:
        bm.update_edit_mesh(o)

    bm.free()
    o.update()


That part of the UV map is not assigned to an image. If you just select the face, you'll notice that the image in the UV/image editor disappears.
Select the face and then select the image in the UV/image editor to "assign" it. To be sure of this not happening again, you should probably do this with the entire mesh selected (A).

Note that with proper materials/textures setup, this won't affect the render.

Also see How is this blendfile hiding textures?


There are generally four steps to make sure the viewport alpha display:

Set Transparency Alpha value to 0.000 in Material setting;
Toggle Alpha influence in Texture setting;
Switch to GLSL shading mode in 3D View Property panel;
Use Texture as viewport shading type.

Besides, make sure Using Alpha is toggled in Texture panel, although it's set as default. And you may want to use UV as the coordinate type of texture mapping for most of the case.

However, it is interesting that you can even preview it without assigning any material, even in the default Multitexture shading mode (just like when you drag and drop an local image onto a object in the scene). And of course, it cannot be rendered, since no material assigned.


Preview is accurate, but export / render is overexposed / too bright when there's a layer on top

A couple things occur to me:

Your Materials. I noticed your materials in the second screenshot. Why use an Emit value instead of cranking up the Intensity and checking Shading > Shadeless? This could bleed over and cause the brightening.
Text in the VSE. Is your text animated? Does it move or change? If it doesn't, you should really consider using Text strips instead of Scene strips. To add a Text strip, key Shift + A, then mouse over to Effect Strip > Text. In the VSE's Properties panel (key N to toggle open/close) make sure Edit Strip > Alpha Over is selected in the Blend: drop down menu. This will make sure that only the text is displaying. Lastly, go to VSE Properties panel > Effect Strip > Text: and enter your text.


Difference between bump map and normal map

This has nothing to do with blender, but could be useful anyway.

The normal map contains pixels with vectors. Each pixel has a vector, where is that pixel pointing. In the standard light blue purple color, it is pointing straight out from the surface. As the color changes, it points in different directions.

A heigh map (or bump map) has a height value stored as a value between black (lowest) and white (highest).

The bump maps in your post doesn't look like it will produce roof tiles when projected on a flat surface.

They describe about the same information, in different ways.

Looking at a single pixel in a normal map, it is impossible to say what height it is. Just the way the surface is tilted (direction and amount). But if you look at more pixels surrounding it, you can build up a relative height. If you stand on a slope, you can see that, up the slope, the ground is higher.

Looking at a single pixel in a height map, it is impossible to say what slope it is. But you know exactly how high you are. But by looking at your neighbours, you can work out a slope.

To work with a normal map in a material in blender, you have to run it through a Normal map node. This also have a strength value, to determine the scale of the bumps.

EDIT:
To me it looks like your bump map isn't meant to be put on a flat plane. It looks like baked normals for a lowpoly model of roof tiles. I don't know where you got these maps.

The normal map you have, that will give roof tiles when mapped onto a flat plane. Not very good ones if you get close. But from a distance, it will work.

Here is an image I made, showing the difference. Normal map on the left.


That picture has only face selection mode right?

Because I can see a whole bunch of zero area faces that are going to be confusing.

First thing you should do is try to get rid of those faces by selecting everything and merging vertices by distance (use a very small distance).

Once the faces are cleaned up you should be able to easily cut the edge loops you want either with the knife tool or by dissolving and re-adding with ctrl + r.


In fact, it does subdivide but you don't see it because the scene is in edge selection mode. And as there is no vertex in the center, only border edges are divided.

But what you can use is a grid fill CtrlF then "grid fill":


Heightmap-based displacement with 90-degree corners

Here’s one way to do it mostly non-destructively:

Start with a plane.

In edit mode, use CtrlE ▸ Subdivide to subdivide the plane into a 16×16 grid.

Add a Bevel modifier with Limit Method ▸ None, Amount ▸ 0.0001 m, and Segments ▸ 1. This creates some additional geometry so displacements are sharp.

Add a Displace modifier using your height map texture. Under the texture options, make sure to disable the Sampling ▸ Interpolation option, so the boundaries of the height map will be sharp. This produces a nice, sharp result:

To clean up the geometry, add a Weld modifier followed by a Decimate modifier set to the Planar mode. This will delete most of the redundant edges, leaving a clean, low-poly mesh:


Cycles still is a approximation based path tracer. this means everything you see in the rendering is getting calculated by randomly shooting rays. per path blender is only shooting one ray per pixel (correct me if im wrong). this information contains "is this pixel getting light, or not". If yes, the pixel gets white, if not, it is getting black. this is why you only have black and white pixel at 1 rendered sample. If you shoot another ray, your information (light, yes/no) is getting mixed, so that a grayscale is calculated. the more sample pathes, the more accurate your image.

10 Samples is a good amount of samples and there is little you can do to even improve this number.

Only thing you can try is the upcoming denoiser for blender (download a WIP build here http://blenderartists.org/forum/showthread.php?395313-Experimental-2-77-Cycles-Denoising-build). But i dont think you can go under 5 samples.


Blender can denoise its own animations. Can it denoise a live shot?

Here I am, answering my own question. I have not found any way at all to use Blender to remove camera noise. The AI Denoise node now included with Blender does not affect live-action footage.


Is there any way to prevent lights in linked files from behaving very differently?

Instanced light don't cast shadows in 2.80, EEVEE doesn't support casting shadows from duplis (particles, collection instances, duplifaces, etc.). It is a know limitation of the current system.

In 2.82 and forward the shadow system has been reworked to allow this, so either wait it out, try the risks of using an experimental version, or you will have to make your light setup local.


I'll answer regarding the white/orange chair.

The outer spherical shell and the base are easy enough to model. You can start with a sphere and use the Solidify modifier to give it thickness. If you rotate the sphere you can simply cut out part of the sphere to get the opening. The base can be simply modelled by extruding a circle.

The more difficult part is the cushion. I would start by box modelling the approximate shape and position of the cushion and the sculpt it into the final shape and position. You can see the cushion gently hugs the opening of the chair so that would need to be modelled/sculpted into place.


Why does my cloth simulation fall even though it shouldn't?

Increase Physics Properties > Collision > Softbody And Cloth > Friction value for bed (mattress) object.


Use spotlights instead. The sun lamp is a special case where the position of it doesn't matter, only it's direction. You could possibly choose to disable shadow rays (Object properties -> Visibility -> Ray Visibility: Shadow) but I doubt that you'll get the desired result.


Transparent blue plastic material which emits light

I would use two objects (or separated parts of the same object), the emitting object being separate from the cover.
As far as the materials go, it depends on how much you want to fake it to increase render times/decrease noise.
Realistic
A realistic setup is probably the simplest, with just a simple emission shader for the emission object and a glass shader for the cover.
I've used clipping border (⎇ AltB) to give you a cut away view of the objects:

The main thing to note is that the cover is not solid, it is hollow (this can be done with a quick solidify modifier). The reason this is important as it has a large impact on the way light is refracted through the cover.
With some simple compositing to simulate the way a camera will behave when exposed to a bright light source (bloom), a nice glow can be achieved:

The downside to this is that it will produce a lot of noise. This image was rendered with 1000 samples, but as you can see it still needs some more:

Fast/less noisy
This is more complicated, but should help rendertimes by reducing the amount of noise at the cost of physical accuracy.
There are probably several ways to optimize such a setup, but here's one of them:
The main point here is that a point lamp is used to do the actual illumination  instead of the emission mesh.
The point lamp is also not refracted, it's light is allowed straight through the cover, but absorbed where the cover mesh is thicker (kind of faking those nice caustics from the "realistic" example)
To make sure the volumetrics don't cause too much of a slowdown, make sure volume sampling is set to Equiangular and that Homogeneous is enabled on the cover material:

Rendered in 200 samples:

As you can see, there is still a little noise, mostly caused by the mesh light which is emitting light that gets refracted/reflected by the cover. I couldn't immediately think of a solution which would make the mesh light only illuminate the inside of the cover, and not refract outwards.
The only reason the mesh light isn't making as much noise as in the "realistic" render is that it is dimmer than in the realistic version. This isn't very noticeable though, since the lamp provides plenty of light.


Cloth modifier. Is it possible to set spring rest length and bending angle?

So, I have been trying to do this on my own by modifying Blender source code,

in the file 'source/blender/physics/intern/BPH_mass_spring.cpp', in the function 'BPH_cloth_solve', just after it gets the reference to the Cloth object (line 1080), I manually set the rest angle of every spring to 0.0f,

this seems to do the trick w.r.t. bending,
problem now is the rest length,

I'd like to be able to define a vertex group that shall have uniform spring rest length,
I think this could be achieved by adding an additional flag to ClothVertex class (source/blender/blenkernel/BKE_cloth.h, line 96), and changing the ClothModifier so I can add an additional field with a vertex group (and maybe a checkbox to activate this behaviour), then, I think I should set this vertex flag at 'source/blender/blenkernel/intern/cloth.c', function 'cloth_apply_vgroup' (line 650), this should allow me to have access to which springs belong to this vertex group, so in the same part of the code I set rest angle to 0.0f, I can compute an average spring length for those springs and set it as rest length,

nevertheless, I am a little lost on how I can change the Cloth Modifier so that I can include an additional field with a vertex group, so that it later becomes a field of the object ClothModifierData on 'cloth.c',

if anyone has a better picture of how blender source code works and can share thoughts on this I'd be very thankful,

I'll keep trying to figure it out by myself, and if I see reponses from other people that have the same problem, I can share whatever solution I finally come up with


(Rigging) Character with Spikes on Back: What do I Parent the Spikes to?

Don't add bones to the spikes, but instead, just have the weight the spikes to the max with the corresponding "spine" bone. So for example, take the top two spikes, and weight paint them so they only move with the top back bone before the neck. You'd only need to add bones to the spikes if you intend to move them with the bones that you placed inside them. If they're static, just weight them to whatever back-bone makes sense for the position.
The same goes for other things that protrude/hang off a character. For example, if your character had a backpack, you'd set the weight for the backpack to move with the back bone. If your character had a watch, you'd weight the entire watch to move with the forearm's bone.


Make a mesh/plane deform on collision (and stay deformed)

As suggested by timaroberts shapekeys could be a way to achieve this.

Shape keys a are a way to store or save a geometry state of you mesh, allowing to animate by morphing or blending between them freely.

Add a new plane object
Subdivide it as much as you need
Exit edit mode and go to the Properties Window > Object Data > Shape Keys
Add two shapekeys (base and one to make your deformation)
Select the second key
Enter edit mode
Turn on proportional edit with O key (letter "o" not zero)
Grab the central faces or vertex and move them down in Z axis
Use Mouse Wheel Scroll to adjust proportional editing size accordingly
Exit edit mode and you can blend freely between shapes.


How can I cut a complex Blender object in half?

Bisect Tool
If you need precise adjustment - open tool properties (left-bottom at 3D viewport editor) and set cut numerically.
For 3D print you would need to have a mesh as manifold, so check Fill option.

After Bisect operation, when cut edges are selected search for Edge Split to separate a half. With mouse cursor close to an one half click L to select linked (or box select.

Or box select a half and click P > Separate by Selection


python script to move another object when a certain object is moved

You can use drivers to do this, or use a constraint. The constraint is probably the fastest option (performance-wise), as they are written in C.

If you want you can even add drivers or constraints via Python, in case you want to have scripted control over those.


Blender uses blender units. You can switch to using metrics as shown below:

For 2.8X

For 2.7X

You can then make sure of your model dimensions as shown below:


OP (me) didn't realise that a weight value of 0 auto-removes a vertex from the group. Also you need to use the index for accessing the weight data. So this works:

import bpy

ob = bpy.context.active_object
vertexGrp = ob.vertex_groups["Group"].index
for poly in ob.data.polygons:
    weight = 0
    try:
        for vert in poly.vertices:
            weight += ob.data.vertices[vert].groups[vertexGrp].weight
        weight /= len(poly.vertices)
        print(weight)
    except:
        print("no vgroup")


Nevermind! I solved it! I had to put cones jutting out with some shaders applied, and point lamps behind them. See some of the other volumetric lighting questions for the nodes to use!


You can try adding a scratches map to your glass material. A quick Google search for "scratch bump map" can lead to some good results.

For the nodes, I would suggest two Glass BSDF shaders, one with 0 roughness and one with 0.4 roughness, run into a Mix Shader (0.4 Roughness one in top shader input). Use the image as a fac in the Mix Shader. You can add a Bright/Contrast node between the Image Texture and the Mix Shader. Adjust the Bright: value to affect the roughness.

Unfortunately, I can't post screenshots right now.


Having troubles finding Regular Solids with blender 2.78

1- Go to File -> User Preferences -> Add-ons and under Categories click on Add Mesh and enable Extra Objects.

2- Click on Add -> Mesh -> Math Function -> Regular Solid.

3- Press "T" to bring up the tools (if it is not opened already) and under (Regular) solids scroll down till you see Presets and select "Truncated Icosahedron".

Good luck!


Is it possible to apply a bezier curve along a mesh?

Yes, you can use the Shrinkwrap modifier. Select the curve and add the modifier to it, then as its target, select the mesh. It will snap the curve to the surface. The settings are pretty intuitive so to get a nice result you can just tweak the settings. Try changing the Mode to get a bit more control over how the curve is projected.


I think this is somewhat related to this question. I solved this by restarting the blender in the end...


When importing stl models for 3d printing the pieces are all scattered, Is there a way to re assemble everything?

I'm afraid there is no other solution than manually fixing it.

It looks like a 3d printing model, and the parts are designed to be printed separately then assembled (it even look like an articulated model). Maybe try to contact the author, they probably have an "assembled" version of the file.


texel density real life like textools 3ds max

TexTools has been released for Blender and already features Texel Density tools. You can download and read more on my website.

Unlike the 3dsMax version there are now some advanced options on how to apply the UV scale


Baking normal map for mutiple objects and merge them

Uncheck Clear option in the Bake panel. By doing this, you can bake the body and the wheels separately and with different options, but the normal map will be dinamically updated when you bake the second object. So your output will be a single normal map for the two objects, which stores normal data of both objects. Just make sure the two objects are using the same normal map as target bake texture.

This option is available both for Blender Internal and Cycles.

Blender Internal:

Cycles:


What is the Reason Cycles Creates Incorrectly Colored/Firefly Artifact Pixels?

Fireflys aren't incorrectly colored. In theory, you need them for a correct rendering result. They are only a representation of a part of your light that is very difficult to sample for the renderer and therefore magnitudes more noisy than everything else.

The problem with them is that they represent a path that a ray is very improbable to travel on. For example, if you have a reflection or a refraction of a very small but strong light source, the probability that any sample will reflect/refract in a way that will hit this small light source is very small. If it hits it, however, the result shows that this should have a big effect on this part of the surface, so it samples a very bright pixel there.

That would be no problem if, for every pixel, a few samples would eventually follow this path and create a bright pixel there, but due to the small probability, only very few ever follow it and these pixels are then far too bright (because they found the way "too early" and are not yet averaged out by the other future samples that would all not find this way).
On other pixels, no sample will find the way at all (within the numer of samples you set in your render settings) and are therefore too dark (but only very little too dark, because the actual effect of that light on the surface would not be that big).

So if you would render, for example, 10,000 times as long as you do, the fireflies will eventually become more and weaker and, in the long term, become a normal, noise-free part of your light. It's just impossible to sample for that long.


Texture Paint is missing in the menu - how do I find it?

Your UI is significantly altered from the default. I noticed one tab labeled “game logic“ and I’m wondering if this is actually leftover UI from an old 2.79 blend file. However, the tab you need might be still there. Hover the mouse over the tab area, and then scroll. If you still don’t see the tab, click the little plus tab at the very end, and you’ll see what you need in the “general“ section of the appearing menu.


Is there a list for Keyframe data_paths in Blender?

You can right click the property in the user interface and choose Copy Data Path

You can also key it manually and explore the object's animation data with the outliner using the data block option.

or view it in the graph editor

You might try to create a list yourself:

import bpy

obj = bpy.context.active_object
txt = bpy.data.texts.new("list")
for prop in obj.bl_rna.properties:
    if prop.is_animatable and not prop.is_readonly:
        txt.write(prop.identifier + '\n')
    elif prop.type == "POINTER":
        txt.write("---Pointer--- \n" + prop.identifier + '\n')
        for sub in prop.fixed_type.bl_rna.properties:
            if sub.is_animatable and not sub.is_readonly:
                txt.write(sub.identifier + '\n')
        txt.write("------------- \n")

It is possible to explore the properties with the outliner:


How can I make a view that seems like orthographic, but not exactly?

With some limitations (or I haven't found the how to, probably), we can tweak the camera matrix when using Gpu module. So that we can have the equivalent of viewport rendering.

The image above is taken with a orthographic camera placed in front of some cubes:

On bottom left the addon (see below) shows a vignette of the tweaked image.
When in camera view you can move the camera or the object and view the corresponding result of the projection:

To take a screenshot, use the D key.
Limitations:

The camera targets along Y and it Y position is fixed to -8 units
The rendering is limited to the 3D view size
Moving objects along Y may push them out of the view
Works in rendered viewport shading but for Eevee or Workbench only (not Cycles)

Principles of the script:

It is based on simple modal operator template
Uses this documentation example to make the rendering

The "key" part of the code: as we can give to the GPU module the matrices we want, have added empirical values to make the projection (offset and tweak below).
camera_matrix = scene.camera.matrix_world.copy()
# Static camera position in Y
camera_matrix[1][3] = -8

view_matrix = camera_matrix.inverted()

projection_matrix = scene.camera.calc_matrix_camera(
    context.evaluated_depsgraph_get(), x=width, y=height)

# Empirical offset and perspective tweaks
projection_matrix[0][3] = OFFSET_X
projection_matrix[1][3] = OFFSET_Y

projection_matrix[0][2] = TWEAK_X
projection_matrix[1][2] = TWEAK_Y

# Draw the 3D view
offscreen.draw_view3d(
    scene,
    context.view_layer,
    context.space_data,
    context.region,
    view_matrix,
    projection_matrix)

Blend file: execute the script then search F3 for "oblique" in the 3D view. Esc to quit. D to take a screenshot. You can zoom in/out by scaling the camera.

The rendering itself is equivalent to "viewport render image" (menu "view"). So you can have the shading you want and disable gizmo and overlays if you want).


Denoising missing from Cycles scene panel

On the screen blender 2.78 without denoiser.

You should download 2.79b to have denoising function


Fade a mesh out due to animated distance from Empty

The point is to be relative to the "empty" parent.

For that, use it as input in the texture coordinate node (left).

Then few calculations (simply the distance sqrt(xx+yy+z*z), modulated by the "2" input value), to drive the mix shader. If only the Z interests you, you can simplify that.

if the cube moves :

If the empty moves :


FPS drops sporadically, with Gsync turned on, even with just one cube in the scene

Yes it's possible. Go to nVidia Control Panel > Manage 3d Settings > Program Settings.

Add Blender under Select Program To Customize. Changing to the following settings fixed the g-sync stutter problem for me:

Monitor Technology: Fixed Refresh
Preferred Refresh Rate: Application-controlled


From the pictures you've provided, it appears that you do not have the same number of vertical spans for the head mesh and the neck mesh. They will need to be the same before they can be properly joined. You won't want to count them manually, so just select each of the edge loops in Edit Mode individually, and then look to the bottom right of the screen to see the number of edges and vertices for each of the selected edge loops. This will tell you exactly how many more spans one mesh has than the other. It looks to me as if your neck mesh is the one which has more.

If you don't see this information, right-click on the field where it should appear, and a menu will appear. Check the box that says Scene Statistics. Now you can see the information.
Fixing your kind of topology problem can be a headache. You could try to remesh the parts to fix it, but I find that it's more straightforward to simply manually select and delete the extra spans. If you are worried about how that may damage your model's shape, you can try to retain it by shrinkwrapping your body mesh to an unedited copy of the body mesh, then delete the spans for your project body mesh, and then adjust the remaining spans on it with by edge-sliding the spans into somewhat better positions. Shrinkwrapping to the copy mesh ensures that the overall shape will be preserved.
If you don't want to delete any spans, there is another way to get this done. You could add spans to the head instead of removing them from the body. One nice thing about going this route is that it won't interfere with your shape. But it will create unnecessary geometry, and maybe even ugly topology. You could consider using the Knife tool to add small edges that bring the total count up on the head side of the join, but then those new edges you create will have to end up going somewhere. There is a trick that prevents you from needing to follow a newly created span all the way around the object you're adding it to. You can get rid of any two extra spans at the same time by tracing them into the new mesh area and then making sure they meet one another at the centerline of the mesh. To keep things all quads, though, you will want the vertex that defines the 90 degree bend that this solution requires to be joined to the nearest corner vertex. It looks ugly, but it gets the job done (Newly added knife cuts shown in dotted green; centerline shown in dotted red).

Your neck mesh looks especially problematic from the side. You may have to use loop tools (an addon which is included with Blender, but not on by default) to straighten and round out the neck hole. You should probably also partially rebuild the topology on the side of the neck so that the edge flow is consistent with that of the head.

When you finally get the spans to be the same number for both parts, your bridging of the edge loops should work. But be aware that you must be sure to join your mesh parts before beginning this operation.


COLLADA export doesn't preserve animation for all bones

I figured out the first problem. Based on suggestions from this BlenderArtists thread and this extremely helpful Wildfire Games article, I figured out that I needed to bake the animation with the 'visual keying' box selected. To access this, I selected the skeleton, then navigated to Bake Action (Pose > Animation > Bake Action...) and checked the 'Visual Keying', 'Clear Constraints', and 'Clear Parents' boxes. These options also take care of rigs that include inverse kinematics.

As the Wildfire Games article suggested, try to avoid unchecking 'inherit rotation' on any bone, as it will not export properly.

(As for the tiny bones problem, I have no idea what's going on there)


Animating the merging of multiple video strips

There are a couple ways, but I would use masks:

With a strip selected, add a mask modifier in the properties region (N) by pressing Add strip modifier > Mask. I also like to set the alpha blending to alpha over:

You can either use another strip to control the selected strip's alpha channel. You could use a scene strip to generate such a map based on the render output of a scene, or you could use an animated mask.
To create a mask, use the UV/image editor with the mode set to mask. Press ⇧ ShiftA and select the type of mask to create.
To animate it, transform it with G (translate) S (scale) and R (rotate). Insert keyframes with I.

To move the keyframes around/delete them, you can use the dopesheet in mask mode:

Unfortunately there doesn't seem to be any way to get the image editor to update in realtime at the moment, so you'll have to manually refresh it by pressing F12. For that to work, the viewed image must be set to Render result.

Result:


I had another problem which were random yellow pixels in viewport rendering. When looking up a fix for that I came across this thread on reddit.
https://www.reddit.com/r/blender/comments/a278rj/anyone_else_have_this_problem_when_viewpoint/
When enabling Screen Space Reflections, it did not only solve the weird yellow pixels problem, but also the rendering issue. I am not sure what exactly was causing this problem to occur. If someone knows, please leave a comment, because it really does help other people understand the engine.


Can python scripts be used to make a simple real time game in Blender 2.8?

Yes.
A game is an activity that one engages to have fun. By this definition a game can be made using pretty much anything.
Python is a powerful programming language and it can run in Blender 2.80. You do not need any of Blender's functions to script even a very sophisticated game in Python alone and run it from inside Blender. Blender 2.80, even though it is not designed to make games in, has a lot of functionality in general and that functionality can be manipulated using Python and Blender's Python API so there are even more tools there that can be used to create environments or situation suitable for activities one could engage to have fun. Blender is not designed for this purpose, however there is nothing stopping you from coming up with ways to have fun.
There are other questions that might be relevant to your context that might be useful to consider. For example - time needed to learn functionality of Blender and time that you will need for learning to use its Python API. Because of the amount of information we are talking about time in terms of weeks and months, possibly even years here. Learning to use Blender and its Python API can be very useful as well as a lot of fun and can bring you a lot of satisfaction and pleasure, however it might not be an amazing idea in the context of a class project, unless you enjoy unrealistic goals and failure. Another thing to consider - are there maybe better tools for the task that could be easier to learn and use for the specific purpose? There must be some reasons people use game engines to create games. Is it possible it might make more sense to look into open source game engines in your situation?


why the particles not coming on the top of mesh

You did not the check Rotation box in the particle settings, so all particles have the same orientation and rotation as their source: "Plane.004"

And you used the vertex group "Group" to emit particles form the entire lower body of the bird.

Together these two things cause a lot of the feather particles to stick through the lower body mesh.
Possible solution:
You could make the vertex group smaller. For instance: limit the used vertex group to only the middle bottom edges of the body of the bird (highlighted and selected in the image below). Then there would only be feathers on the bottom of the body, and only a few would stick into the body a little:

Other things you can do:
(but might not fit your needs)
1:
You have very little control over the location of the particles because your model is very low-poly (or low resolution in terms of vertices). If you apply your Subdivision modifier you can be more precise with the location of emission via vertex group.
2:
You could check the Rotation box in the particle setting and for instance choose Normal for the Orientation axis.


Is it possible to use D-noise from a picture?

As we can clearly see on https://remingtongraphics.net/tools/d-noise/ after entering "d-noise" on pretty much any search engine and clicking the first result it says:

Denoise Anything
D-NOISE isn’t exclusive to renders like the Cycles denoiser is.
D-NOISE can run on any image loaded into the UV/Image Editor including
texture bakes and even photos!

And here is a screenshot of that:


How to cut a mesh into smaller pieces with python?

I don't think hijacking select_border() is a good approach. You could use the new bisect_plane() bmesh operator to slice your mesh.

Here's a straightforward script that slices a mesh into an aligned grid:

import bpy, bmesh
from bpy import context as C

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

bm = bmesh.from_edit_mesh(C.object.data)

edges = []

for i in range(-10, 10, 2):
        ret = bmesh.ops.bisect_plane(bm, geom=bm.verts[:]+bm.edges[:]+bm.faces[:], plane_co=(i,0,0), plane_no=(-1,0,0))
        bmesh.ops.split_edges(bm, edges=[e for e in ret['geom_cut'] if isinstance(e, bmesh.types.BMEdge)])

for i in range(-10, 10, 2):
        ret = bmesh.ops.bisect_plane(bm, geom=bm.verts[:]+bm.edges[:]+bm.faces[:], plane_co=(0,i,0), plane_no=(0,1,0))
        bmesh.ops.split_edges(bm, edges=[e for e in ret['geom_cut'] if isinstance(e, bmesh.types.BMEdge)])

bmesh.update_edit_mesh(C.object.data)

bpy.ops.mesh.separate(type='LOOSE')
bpy.ops.object.mode_set(mode='OBJECT')


After some researches and reading on Blender API I created that script and it worked perfect, so I created my own exporter :), so happy

import bpy

class ExportSceneToBoddooo(bpy.types.Operator):
"""Test exporter which just writes hello world"""
bl_idname = "export.scene_to_boddooo"
bl_label = "Export to Boddooo"

filepath = bpy.props.StringProperty(subtype="FILE_PATH")

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

def execute(self, context):
    file = open(self.filepath, 'w')

    file.write("<Level> \n")
    file.write("    <Meshes> \n")
    for ob in bpy.data.objects:
        locX=str(ob.location.x)
        locY=str(ob.location.y)
        locZ=str(ob.location.z)
        rotX=str(ob.rotation_quaternion.x)
        rotY=str(ob.rotation_quaternion.y)
        rotZ=str(ob.rotation_quaternion.z)
        rotW=str(ob.rotation_quaternion.z)
        sclX=str(ob.scale.x)
        sclY=str(ob.scale.y)
        sclZ=str(ob.scale.z)
        if ob.type=="MESH":
            file.write("        <" +ob.type + " name='" + ob.name + "' location='"+locX +" " + locY+" " + locZ+"' rotation='"+rotX +" " + rotY+" " + rotZ+" " + rotW+"' scale='"+sclX +" " + sclY+" " + sclZ+"'/>\n")
    file.write("    </Meshes> \n")
    file.write("    <Lamps> \n")
    for ob in bpy.data.lamps:
        clrX=str(ob.color.r)
        clrY=str(ob.color.g)
        clrZ=str(ob.color.b)
        energy=str(ob.energy)
        file.write("        <" +ob.type + " name='" + ob.name + "' location='"+locX +" " + locY+" " + locZ+"' rotation='"+rotX +" " + rotY+" " + rotZ+" " + rotW+"' color='"+clrX +" " + clrY+" " + clrZ+"' intensity='"+energy+"' />\n")
    file.write("    </Lamps> \n")
    file.write("</Level>")
    return {'FINISHED'}

def invoke(self, context, event):
    context.window_manager.fileselect_add(self)
    return {'RUNNING_MODAL'}

# Only needed if you want to add into a dynamic menu
def menu_func(self, context):
    self.layout.operator_context = 'INVOKE_DEFAULT'
    self.layout.operator(ExportSceneToBoddooo.bl_idname, text="Boddooo Exporter")

# Register and add to the file selector
bpy.utils.register_class(ExportSceneToBoddooo)
bpy.types.INFO_MT_file_export.append(menu_func)

# test call
bpy.ops.export.some_data('INVOKE_DEFAULT')


Problems with weird edges after Subdviding/Smoothing surface

Ur Problem is the face orientation. If u Turn on "Face Orientation" on and check, u can clearly see half of ur face is its back facing outside (Red is the back of the face, Blue is the front of the face. Generally, u shoud have all faces blue)

select all ur faces and type F3, search for "recalculate outside" to correct ur wrong facing direction. then it should smooth properly


Ruler use the Global coordinates

As you already pointed out in your question, the difference comes from the using of Local coordinates instead of Global.

While the Global coordinate of the vertex is its "true position" in the 3D space, Local coordinates are giving you the position of the mesh component as if it would not be affected by the object's transformation.

If we consider for example a 200x200 square plane, and set the object's scale to 0.01, the Global position of the corner vertices would be something like (1;1;0)... while the Local position will stay untouched (object's scale is uneffective) resulting in something like (100;100;0).

The rulere is giving the "real" distance bewtween two points, located where they currently are in the scene, so by comparing the Global coordinates, not the Local.


Why is this passive rigid body allowing objects to pass through it?

You can add a collision margin on the plane (the passive rigid body).

Also, increasing the number of simulation steps per frame from the rigid body properties panel in Scene properties tab will give you better results.


Why is my cube looking like this with the glass material?

No need to overcomplicate things.

Here is how you do it:

Solution 01 (physically accurate)
Use Principled BSDF shader

Leave everything as is (very important)
Set Transmission to 1
Set Roughness as desired
Boom, you have realistic glass.

Solution 02 (old, not physically accurate)
Use Glass BSDF

Set roughness as desired

Example of both, side by side:

Tip:
If you're going for realism, use Principled BSDF wherever you can. It solves many issues for you such as fresnel, light fall-off, etc…

BlenderGuru explains all of it’s nodes.


Why is a piece of this mesh stuck in pose mode?

The problem is that the particular vertex is not assigned to the bone that you are moving. Fix it by going into weight paint mode and painting that vertex red!

Unfortunately, weight painting disagrees with my computer so I can't post an image. :( I will try to have someone put one in for me


IK not working for legs, where am I wrong?

The legs need a bend in their default position.  Select the armature, go into Edit Mode, and push the knees forward a tad.  Here's what it should look like after that.

Also, consider reducing the leg IK chain length to 2.  This will make the bending more predictable.


Select the upright glass section then apply a Screw modifier and choose the Y axis in the properties.


Some part of my character is not very well lighted

Even though this is quite a simple mistake beginners only make, we are here to help you and you are here to learn!

As I have seen from your file, you have used a point light as your only light source. If you make this a sun lamp you will have directional light that will emit the whole scene from the same perspective. The point light emits light in all directions from one point. Your characters' faces are casting a shadow onto other parts of the face because the lamp is not shining from the front of the characters. Here's what you can do:

Rotate the lamp on the X-axis towards the characters. Not literally on a 90-degree angle, but on a slight angle. Maybe rotate it like 35 degrees. The light now hits the front of the characters.

You can also add a plane with the surface facing towards the characters from behind the camera. Get it about as long as the space between the characters. Also make it as high as them. You should add a new material using the emission shader. Play around with the strength values until you like it. You can also play with the position of the plane. You can also get it up a little higher than the characters and make it face it their way too to get a little more contrast of the curves of their shape.

I hope this is working out for you. Good luck!


How can I move a UV Island to simulate the Movement of an Eye

Ok... it seems it is needed to complete a previous answer (Creating an eye/eyelid rig for dragon without shape keys)...

You are more or less in this situation with a single UV map and a single texture. The eyes are here selected on the left.

On the right, you can see two vertex groups (named WarpLeftEye and WarpRightEye) : each of them is assigned the corresponding eye vertices.

Now, add two empties. Here I created a sphere and a cube one (in order to see who is who). Then setup the UV Warp modifier this way, using the two empties (or any objects or bones) and the vertex group for the left eye (do the same for the other eye) :

Here is the result :

Surely, you'll need to have enough space around the eyes in your texture. If not, add another one as suggested in the comments.
You can also use the UV map field of the modifier to use another UV map done for the eyes.

Note : scaling and rotating work too... more or less easy to do but simply scale and move and/or rotate the empty (scaling will shift too : so you'll need to scale a bit, realign, scale a bit, etc.)


Array object in straight line but rotate object on z axis

Dupliframes Method:

The first step is to keyframe the location of desired object at the origin at the first frame (0 or 1). Then we will add a keyframe 10 frames from our first, since we want 10 iterations, at location (5,0,0) and key a rotation of 300 degrees since we would like each iteration to be rotated 30 degrees from the previous (300 = 30 degrees each iteration * 10 frames). In the curve editor we want to make sure that we're using linear interpolation (select keys and press 'T'). This makes sure that the iterations will be evenly spaced. In the Object propeties tab, find Duplication and select frames. Since we only want 10 iterations we will end at frame 10 (It may look correct if left to 100, you will have extra meshes in the same location as the last iteration. Finally when happy with the result we can convert the dulpliobjects to real objects with Ctrl-Shift-A, and Ctrl-J if desired.


How to spawn and kill objects during animation to save memory?

Here are some ideas:

One of the main problems is probably that the fan has way too many faces (you even have completely useless bolts, you certainly won't make any close-up shots on this), so you should simplify it a lot: Make it an independent object, delete a lot of edge loops,  give it a Subdivision Surface modifier with a level of 1, and an Array modifier so that it follows the tunnel. Tricks to simplify: Use CtrlE > Un-Subdivide, or use select edge ring, Select > Checker Deselect, Select > Select Loops > Edge Loops, and CtrlX to dissolve. You could also make a very simplified version if it's far away from the camera. Here is just a beginning of clean-up:

Slide the image texture along the mesh (wall and road) with the Mapping node (not sure it will save a lot of memory though, lol):

Render an image of a long tunnel perspective and use this image in your 3D scene to fake depth (or use a mirror?)
Make only very short sequences


How to make a simple spiral w/ arrow like the Weatherman

None of the suggestions already on StackExchange specifically addressed what I wanted to do. Here's what I finally came up with:

my weatherman-type rendered spiral http://s1.postimg.org/hewpl3ym5/rendered_spiral.jpg

I created a spiral; in Geometry, I used a custom bevel and taper. I assigned it a material. I used hemi light in Blender Render. (So no shadow where one part of the ribbon crosses the other.) I added a 3 point mesh triangle for the arrow and made that a child of the spiral so that it would rotate with the spiral during animation. I added a black border in BR post processing. (Whew! Took 3 days with lots of reading and watching youtube tutorials.)


How do you add the Jiggly Armature code to Blender as an add-on?

Addons are all just code, in one or more files, normally packaged up in zip archive. However if all the code is in one file, they don't need to be zipped up.

If you go to: https://github.com/cheece/JiggleArmature/blob/master/JiggleArmature.py and right click on the button in the top right that says raw, and select save link as you will download a file containing the addon code.

You can then install this like a normal addon. Bear in mind this hasn't been updated in 2 years, so it may have bugs. The addon metadata says it was created for 2.77. That said it will probably be ok in 2.79.

As for any side affects from the addon code, you would have to read the code and check it carefully, as with any other addon. I had a very quick skim and it looks like it just does what it says.


Blender 2.8 PNG image is not transparent even with alpha blend and alpha nodes

You have to change the Blend Mode in the material settings and have to be in Rendered View.

Any of Alpha Clip, Alpha Hashed or Alpha Blend would work for a single image, but for a pixel perfect preview in EEVEE, Alpha Blend is required.

  Alpha Blending
  Use alpha blending to overlay the surface color on top of the previous color.


Remove object from specific group programmatically

If you don't mind not using python, you can just select the objects and press ⎈ Ctrl⎇ AltG, then select the group you want to remove them from:

If you still want to use python, then you want a group operator, rather than a object operator:

bpy.ops.group.objects_remove(group="myGroup")

This will remove the selected objects from the group "myGroup".


What's the difference between DEF bones and ORG bones in functionality?

ORG - prefix for original bones from which the full rig is generated

DEF - prefix for bones contributing to deformation

Usually the ORG bones of the metarig are replaced by generated bones, but in this case the clavicle is used from the original rig and contributing to deformations.

This IMHO is a mistake and should be marked right, a copy of that ORG bone should be generated and marked DEF and the ORG bone moved to a hidden layer where rest of the org bones are lurking, ready to be tweaked and a new full rig generated from them again if needed. If both are the same bone, you do deform the mesh while tweaking the metarig and this is not wanted, the mesh should stay intact. If the org bones are in a separate armature (like with rigify), there is no need to have ORG prefixed bones inside the rig at all.


You can do it like this:

blender -b -y -P master.py -noaudio --addons netrender file.blend

Contents of master.py:

import bpy
bpy.ops.wm.addon_enable(module="netrender")
bpy.context.scene.render.engine="NET_RENDER"
bpy.context.scene.network_render.mode = 'RENDER_MASTER'
bpy.context.scene.network_render.path = "/tmp/"
bpy.context.scene.network_render.server_address = "[default]"
bpy.context.scene.network_render.server_port = 8200
bpy.ops.render.netclientstart()

For the slave you can use the same blender command with a second python script. Create a copy of master.py, name it slave.py or something and change the according line for the mode to:

[...]

bpy.context.scene.network_render.mode = 'RENDER_SLAVE'

[...]

Tested in blender 2.79a.

Note: this is currently broken in the latest daily builds of blender 2.80 (refer here) I'm currently searching for a workarround, to get the new gpu / host memory feature working with automated network rendering, but they'll probably fix it anyways when blender 2.80 comes out.


Duplicate displaced plane and have edges line up?

You can try duplicating the plane and then scaling it by minus 1 along whichever axis you moved it on. That way, you basically mirror the plane so the edges line up. A better way however, would probably be to just use a seamless displacement map.


Is it possible to create an own object data type through Python?

One can extend the objects in Blender (if you want to make your own).
For example take a look at BoltFactory, IvyGen etc, many addons add objects.
However keep in mind that Blender Python is implemented as an API
Adding stuff by inheriting from a base class is possible in python however the rest of the program will not know it, ea dont suspect that cycles or eevee or fluidsims or particles will understand your custom object attributes /methods.

If its only about adding some extra valeu property (maybe fro some other script) then in the normal view of object properties you can add custom attributes as well, perhaps thats usefull to you.
(object tab => add custom properties)

You might not even require python to do so, but if you want to that in code:

bpy.ops.wm.properties_edit(data_path="object", property="demo", value="1.0", min=0, max=1, use_soft_limits=False, soft_min=0, soft_max=1, description="this is demo tool tip")


Python script for adding Child Of bone constraint with 'Set Inverse' to multiple bones?

import bpy

ob = bpy.context.active_object

# Take a copy of current layers
org_layers = ob.data.layers[:]

# Show all layers
for i in range(len(org_layers)):
    ob.data.layers[i] = True

for b in ob.pose.bones:
    for c in b.constraints:
        if c.type == "CHILD_OF":
            context_py = bpy.context.copy()
            context_py["constraint"] = c
            ob.data.bones.active = b.bone
            bpy.ops.constraint.childof_set_inverse(context_py, constraint="Child Of", owner='BONE')

# Reset back to orginal layer state
for i in range(len(org_layers)):
    ob.data.layers[i] = org_layers[i]

Found by Ratt, cheers guys! (let me know if this is what you meant)!


How to create a shortkey for "Replace image" in "UV/Image editor"?

To add the new shortcut in User preferences > Input scroll down to :

click Add New , set up your shortcut as follows :

NOTE: the shortcut name 'Replace Image' will come up automatically

Save your preferences and now you can use your new shortcut

To know what to type for the shortcuts use the tooltips :


Python script has no effect when running as background

I was missing something obvious: I need to render from within the script after I make the changes I need. This exchange helped. Otherwise it renders the image with the command line arguments before the script is run. If I launched Blender with the script or ran the script normally I could run a render later and it worked.

Adding bpy.ops.render.render(write_still=True) worked. All the render settings are set within the scene with the UI.


The easiest way to do this is simple to create an invisible box, parent your objects to it, and then remove your objects from the physics simulation. The box will then do the collisions on their behalf.

Steps:

Remove you meshes from the phsical simulation

Parent your mesh to you box
Make your box invisible, and set the simulation to Rigid Body


Staircase Shadows / Shadows look like faces

The artefacts are rendered due to low subdivision. I reproduced them on a poorly subdevided sphere. Just add another level of subdivision and you should be good to go.


The problem was that I was setting a driver for the MUTE property of the shape key, not the VALUE property. In order to set a driver for the VALUE, right click the value and you will see an option to add a driver.

I was convinced yesterday that it was not possible to right-click the VALUE (as of 2.80) and see an option to add a driver, that I had to right-click the checkbox instead. This was a mistake. Thank you to everyone (@Edgel3D) who tried to help. The problem is now solved.


Shoulders
The arms and shoulders look fairly good to me. When you pose the arm above the head you need to move and rotate the shoulder bone up, too. You can do this manually or add drivers to the shoulder bones so that they are adjusted automatically when you pose the arm.
Shoulder Clipping Driver Solution (In 2 Minutes!!!) by Royal Skies LLC - adds an extra bicep bone and driver
EVERY Shoulder & Collar Bone Driver (In 3 Minutes!!!) - more drivers for automated posing
To smooth out deformation you can add a Corrective Smooth modifier to the body mesh.
In the screenshot, there are no extra bones and no drivers. I've just moved the shoulder bones manually.
Comparison of corrective smooth modifier on/off. No extra bones, just moved and rotated shoulder bone
Hands
You need to add twist bones to your forearms for the rotation of the hands. Else there is massive compression at the wrists as you can see in the screenshots.
Pelvis and Upper Leg Area
Your rig has no pelvis bones. When you add them the deformation around the buttocks and thighs will get better. But the model will look a bit chubby because of the compression in the pelvis/thigh area. If you don't like this you can add a driver to the thigh bone that moves it down when the leg is rotated upwards. Additionally, you can add 2 more deform helper bones that pull the "flesh" (mesh) away when the leg bends. Just keep in mind this requires some manual weight paint. It's easy to do but you need to backup your work before you re-bind the mesh to the armature with automatic weights else it gets overwritten. You can transfer the weights with a Data Transfer modifier.
Pelvis and bended knees
Elbows and Knees
To prevent the "scissor effect" add an extra knee bone. This simulates an offset of the pivot point for the shin bone. To improve it more add 2 helper bones that simulate the deformation of the muscles and fat.
See Advanced Rigging In 60 Seconds! and Knee Clipping Drivers for details.
I've done this here for the right leg/knee. For the left knee, I tested a different method. (Advanced Deformation Series Part Two Intersection Rig (Knees and Elbows). It adds an extra bone and rotation constraint to move the pivot point of the shin bone. It doesn't look that good but I might have done something wrong because of the bone rolls.
A 3rd method I found is this knee rig (Riggy Bits #1: Simulating Volume in Joints (Part 1: Theory and Example)) that has several bones to simulate the moving pivot point in 2 directions and preserve volume. It uses bendy bones that only work in Blender and not in game engines.
Waist
Just subdivided the lower spine bone to improve bending, so she can do sit-ups exercises for example.
Toes
Added a bone to each leg to bend the toes. The automatic weights might need little manual weight paint corrections to bend the toes properly.
[upper body / elbow bones
lower body / knee bones and helper bones (right side of the body)
Note about bone rolls
Please note the bone rolls of the bones. In your rig, the leg bones bend around the Z-axis. In most other rigs (Rigify and tutorial rigs) it's the X-axis. As consequence, you have to swap the X and Z-axis, and the sign (-/+) for some driver variables and bone rotation constraints.


How to Programatically Render Multiple Times with Different Materials each

Okay, so with m.ardito's help in the above comments, this post on Blenderist and some related questions on Stack, I came up with the following Python script, running it with

blender -b filename.blend -P setting.py

Here's the script:

import os
import shutil
import bpy

uvMaps = os.listdir('C:\\GameDev\\UVs')

for i in range(len(uvMaps)):
    if uvMaps[i].endswith('.png'):
    shutil.copy('C:\\GameDev\\UVs\\' + uvMaps[i], 'C:\\GameDev\\UVs\\Actual\\BallActual.png')

    Scenename = 'Scene'

    #quality
    bpy.data.scenes[Scenename].render.resolution_x = 900
    bpy.data.scenes[Scenename].render.resolution_y = 900
    bpy.data.scenes[Scenename].render.resolution_percentage = 100
    bpy.data.scenes[Scenename].cycles.samples = 200

    bpy.data.scenes[Scenename].frame_start = 0
    bpy.data.scenes[Scenename].frame_end = 44
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos1_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)
    bpy.data.objects["Ball1"].hide_render = True

    bpy.data.scenes[Scenename].frame_start = 45
    bpy.data.scenes[Scenename].frame_end = 77
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos2_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)
    bpy.data.objects["Ball2"].hide_render = True

    bpy.data.scenes[Scenename].frame_start = 78
    bpy.data.scenes[Scenename].frame_end = 108
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos3_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)
    bpy.data.objects["Ball3"].hide_render = True

    bpy.data.scenes[Scenename].frame_start = 109
    bpy.data.scenes[Scenename].frame_end = 135
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos4_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)
    bpy.data.objects["Ball4"].hide_render = True

    bpy.data.scenes[Scenename].frame_start = 136
    bpy.data.scenes[Scenename].frame_end = 160
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos5_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)
    bpy.data.objects["Ball5"].hide_render = True

    bpy.data.scenes[Scenename].frame_start = 161
    bpy.data.scenes[Scenename].frame_end = 181
    bpy.data.scenes[Scenename].render.filepath = 'C:\\GameDev\\Balls Sprites\\Ball_' + uvMaps[i][:-4] + '_Pos6_###.png'
    bpy.data.scenes[Scenename].render.use_placeholder = True
    bpy.ops.render.render(animation=True,scene=Scenename)

    bpy.data.objects["Ball1"].hide_render = False
    bpy.data.objects["Ball2"].hide_render = False
    bpy.data.objects["Ball3"].hide_render = False
    bpy.data.objects["Ball4"].hide_render = False
    bpy.data.objects["Ball5"].hide_render = False

The idea here is that each Ball is coming out from behind a Masked object and travels a number of Frames until it reaches an end, spins down and stops (end_frame). The animation is one long animation from 0 to 183. Each ball begins the travel after the previous one has completely stopped.

By hiding the previous Ball each time, I'm allowing to completely disregard the previous animation - using each Pos (in the file name - from 1 to 6) to be used as a different layer in the Spritehseet I'm creating from these animations.

Since all 99 animation sets are the same, I've created 594 different animation combinations. To be used as sprite animations in a 2D game.

Update:

After running this for three whole days, and barely passing half of the 99 ball renderings, I've added this:

bpy.data.scenes[Scenename].cycles.device = 'GPU'

See a tripling of speed, on average.


It looks like you do not have the camera set up as the active camera, you have an object set as camera.

So, select the camera by opening up the tree (left click on it):

Now, set it as the active camera by going to View -> Cameras -> Set Active Object as Camera.

Now you should have the camera working (as in it moves around in the animation)!  Jumping to a frame, it looks like this:


How do I export my rendered Animation images to disk/save them after rendering?

That just sets the default path for new blend files.

You need to set it up in the Output Properties Panel


Cell fracture and animating rigid bodies

I have solved this with the help of the Fracture Modifier Build of blender. You can find more info and download it here:

http://graphicall.org/1148

I also included the steps in a text file inside the modified blend. Open this blend only in the Fracture Modifier Build or you may experience crashes and data loss in the blend.


How do I animate a single face of a mesh?

You cannot keyframe vertices directly, but several possibilities to do that.

For instance:

Using an armature:

Create an armature, create bones in it and assign the wanted names to the bones (ie states names), in the map assign the wanted vertices to groups which are named the same way. Parent the map to the armature using 'with empty groups' option (as the groups are already created).

pros/cons: can grab, rotate, scale the parented group as you wish

Using a shrinkwrap:

Add a shrinkwrap modifier which applies on a vertex group. Here you can animate the plane target use in the shrinkwrap.

pros/cons: fast to do but static: only up and down movements

Using shapekeys:

Add a base shapekey, then a second one and this last selected, move the vertices to the target place you want. Now you can animate the shape key.

pros/cons: you can place the vertices exactly where you need, but static once done

Using scale:

Here, simply separate the country or state you want and play with its scale.

pros/cons: only for up/down movements

Edit:

Using a hook:

In edit mode, select the vertices you want and CtrlH to hook them:

pros/cons: nearly like bone here: grab, rotate, scale the hooked vertices (or group) as you wish

Using a lattice

Again with a vertex group but here with the lattice modifier.

pros/cons: not the simplest to setup but can grab and scale too.


You have three options,

1) what you want is to rotate bone on custom axis, for this please see
Rotate object on axis between two points

2) if (1) this is cumbersome then i'll suggest, join all mesh (KFlügelR, FlügelL, Vogel, FlügelL, KFlügelL) together (select all mesh and do ctrl+j ). Then assign the armature to this joined mesh, use auto weight for first try . ( if you do not know how to do this then just ask :) )

3) Make the mesh so that its pivot is aligned to the bone orientation.

I'll suggest option (2), as it should be the right way anyhow.


restricting movements to x,y,z for the handicapped

You don't have to hold down they key, just press it once. So you should be able to do it with one hand.

The arrows/gizmo appears if you select the move/rotate/scale tool from the toolshelf (top left). That should allow you to control your objects using just the mouse.

You used to be able to draw gestures to control movement too, but I think that has gone now. This add-on looks like it might help in your case, but I haven't tried it myself: Gesture Ops


Curve after Array modifier messes object dimensions

The radius of the control points of the curve are 14. Set them to 1.


ever tried to resize/re-adjust the unwrapped mesh over the image in the uv-editor?
Works best when watching the render preview simultaneously.
Best regards,
Andal


A: Which bones are you trying to separate?
B: Why would you do that? :)

I think you're probably still in object mode if you're having that problem.

In object mode, press tab to change into edit mode so that you can modify the base/default position of the rig in relationship to the mesh you are trying to modify. If you want to separate a child bone from it's parent bone, say the forearm bone from the bicep bone, press y while that bone is selected. This will keep the bones as part of the same armature, but remove parenting inside the armature. To split them into separate armatures press P.

You should keep them all as one object, however, since they are all interacting with one mesh. What you are probably trying to do is simply enter pose or edit mode.

To go into pose mode press ctrl + tab.
To go into edit mode press tab.


After applying the normal map texture, the meshes in rendered view look WEIRD

Try to change tangent space to different one and see if that'll work. Its always better to apply the specular map and the subsurface scattering map if they have details in them. Try connecting subsurface map to sss color input of bsdf shader (havent used sss maps yet so cant say for sure)?


Clear transform of control armature bones does not reset deform armature bones

EDIT:
I changed the control set up so that the deform armature bone constraints were changed to "inverse kinematics" rather than "copy transform" - I do not understand how exactly, but this appeared to resolve the issue.


What's the fastest and / or craziest way to model an arrow in Blender?

So I thought to myself: These answers are so amazing, but they're hard. Even I have trouble recreating them. I have to do something. I need to provide a simple and effortless answer and after a while, I found it.

Step 1: Create a seven sided Cylinder.

Step 2: Build this ordinary and straightforward armature (shouldn't take long) and connect it to the circle.

Step 3: Push the Bone that has the shape of a modeled arrow (khm) up a bit.

I mean, it doesn't get much easier than pushing a bone up a bit.

To explain:

The orange and red ones are simple 2 bone IK-chains pointing to the mover arrow.

The green ones are parented to the orange ones and move with them. They are not necessary but it's a bit clearer that way. You could parent dark blue directly to orange with offset.

Dark blue is parented to green.

The blue ones are again simple 2 bone IK chains pointing to the light blue targets.

The yellow circle bones sit in the middle of the dark blue bones and are the only ones having deform enabled.

The tricky bit is to find the right lengths for red and orange so that a single bone moves all the green bones just the right amount.

James Watt has discovered this green/dark blue/light blue lever for his steam engines. It's called Watt's linkage. It enables the yellow circles to move pretty much in a straight line. It's still used in trains to keep the wheels from moving back and forth.

The orientation and length of the blue bones isn't just random. I simply put the tips on the arrow verts and the roots on the circle verts. Then I duplicated and rotated them 90 degrees to get the linkage with it's required right angles. Yes, simple rotation of a bone with start and end on a circle would have been enough, but meh...


In the first screenshot, it appears that your mesh has no vertex groups. As far as I am aware, skinning requires that the mesh has vertex groups with the same names as the bones in the armature, and cannot work otherwise. The vertices you want to be moved by a certain bone must be assigned to the matching vertex group. To add vertex groups to your mesh, click on the + button on the vertex groups panel (visible on the right side of your first screenshot). You can also automatically create the vertex groups by selecting the mesh, then shift selecting the armature, then hitting Ctrl + P and selecting Armature Deform with either Empty Groups, Envelope Weights, or Automatic Weights.


How do I increase the loop cut amount on macOS Blender 2.8?

You have to select where you want to loop cut first and click the left mouse button. Then a little menu titled "Loop Cut and Slide" should appear in the lower left corner that allows to adjust the number of cuts. For faster editing you can also use CTRL + R and the scroll wheel to adjust the number of cuts.


There is no scale information in STL file format the units are arbitrary.


How to show an object in the 3D View as a specific color?

Properties > Material > Settings > Viewport Color

IN REPLY TO A COMMENT

"Used when faces have ObjColor mode enabled"


I am running Blender 2.75 on Windows 10 now, the 10240 RTM release, and it is working without any issues compared to my previous run on Windows 8.1.1.


Found my own solution.

stage = own['build']
stage += 0.5

if stage > 100:
    stage = 100
own['build'] = stage

But I'm interested to solve this with "for loop"


It could be something as simple as setting the output quality from 50% (Default) to 100%

You didn't explicitly mention this.


Add an image texture to a shader subgraph

Unfortunately there isn't any way to create a NodeGroup that has a Texture selection as an input without some coding to create Custom nodes. For the Custom node, you'd have to have the image texture node in the node tree, whose value you would change via code using the custom node UI. Please read information in the link below for a much more thorough explanation of this process.
Cycles Materials Math node with more than two inputs


Rendered image shows visible "line strokes" artefacts

The artifact is called color banding and is a common occurence in computer graphics. (Most) computer monitors only have a range of 8 bit per channel. The human eye can differentiate a much greater resolution of light values, especially in dark tones.
See this less specific, but informative article.
Hence, color banding is especially visible in dark gradients. An image with a depth of 12 bit or more viewed on the according viewing device would have practically no visible banding.
Although a bit depth of 16 and higher are today's standard in computer graphics such as 32-bit floating points, which have no banding in theory (most) monitors remain in 8-bit color mode.
Most image related software "solves" this issue by adding noise to the image. This process is called dithering.
Different software manage this in different ways.

The gradient tool in Photoshop has a dither option.

Nuke dithers gradients dynamically in the output viewer.

Blender has a dither slider, this allows the user to control the dithering amount manually.

By default, Blender's dither value is at $0$. That's why you can see the color banding even if the image is rendering in 32-bit floating points. Blender will always render images in 32-bit floating point color depth. Only when you save the image, will Blender convert it to the selected bit depth of the output format.
The image you displayed has dithering already applied. When increasing the contrast we can see the noise, which GIMP added to the gradient.

If we increase the dither property in Blender to $1$ and render the default group, there will be no visible banding artifacts.

Otherwise banding will show (dither value of $0$).

Increasing the contrast afterwards can reveal the dithering noise. (Left, dither at 1; right: dither at 0)

When should I not use dithering?
Do not save images with applied dithering when you plan on processing them further. Save them with a high bit depth (16-bit or more). Postproduction applications can then do color operations correctly and dither the image at the last step if necessary.
Example: A color correction with applied dithering noise would change the amount of noise in some parts of the image thus resulting in uneven dither, which could possibly be visible.
When should I use dithering?
Use dithering in the final step of production, where the product is created which has the chance to be viewed on an 8 bit display. (In other words all final image material.)
Additional Note
Digital movie format (obviously not DCP packages) don't support bit depths higher than 8.


One way to do this:

Set the depth of field to your liking and keep the focus on the object you want sharp, even if adjacent objects on the same focal plane look sharp.
Separate the object in focus in one layer and the rest a different layer.
Assign the layers to different render layers.
On the compositor choose the render layer with the objects you want to defocus, and add a blur node.
Mix the two layers back together.

If you want a bit finer control, use a defocus node instead of blur and control the blur using the Z information.

EDIT

Here's another solution to make "impossible" Depth of Field. Using a color ramp to modify the Z pass on a defocus node.This way you have absolute control on what goes in focus and how blury it gets!

The blend file is here:


# create solid primitive cube to use as duplicate object
bpyscene = bpy.context.scene

# Create an empty mesh and the object.
mesh = bpy.data.meshes.new('Cube')
basic_cube = bpy.data.objects.new("Cube", mesh)

# Add the object into the scene.
bpyscene.objects.link(basic_cube)
bpyscene.objects.active = basic_cube
basic_cube.select = True

# Construct the bmesh cube and assign it to the blender mesh.
bm = bmesh.new()
bmesh.ops.create_cube(bm, size=1.0)
bm.to_mesh(mesh)
bm.free()

and then delete

bpy.ops.object.select_all(action='DESELECT')
bpy.data.objects['Cube'].select = True
bpy.ops.object.delete()


Cycles Gradient Texture node: Why "Linear" is not linear on a "default" plane?

I think that the gradient is linear in its values because at equal increments of the thereshold correspond the same amount of image masking:

As stated by the Blender reference manual's page about Color Management,  Default option does no extra conversion..

  ..besides the conversion for the display device

So a converision still occurs.

By switching to Raw you'll get a result almost identical to the one expected. Again from the same manual page:

  Raw gives the image without any color space conversion

On the right you can see a linear gradient image for comparison.

Object coordinates are calculated from object's origin.

.

If you want a gradient that starts from the bottom of the plane, you should move the origin of the object's texture coordinates (so the Object's  origin) at the bottom of the plane too (the default plane's origin is instead located in its center).


scripting: Modifying an object in edit mode

Okay, I forgot to select all the mesh after toggling to edit mode:

it's working now:

from math import pi
import bpy

obj = bpy.data.objects['my_obj']
# go into edit mode
bpy.context.scene.objects.active = obj
bpy.ops.object.mode_set(mode='EDIT', toggle=False)
bpy.ops.mesh.select_all(action='SELECT')
bpy.ops.transform.rotate(value=pi/2, axis=(False, False, True))
bpy.ops.object.mode_set(mode='OBJECT', toggle=False)


Where is the option 'Display>Only Render" in the latest 2.8 builds?

You can click on the button next to overlays to hide everything:


UV Mapping - During or After Building Process?

Generally, It's best for it to be fully finished before UV unwrapping, because you'll want all your parts to be on the same map.

(mainly because it's a bit less tedious to do it this way.)


Is there a way to highlight a face in the 3D viewport if you have its UV selected?

Yes, you need to enable the Sync button here:


Add Object Constraint has

Copy Location, Copy Rotation, Copy Scale, Copy Transforms

which may assist you.

Please search here at BSE for more constraint information and see Blender Documentation which is amazing.


First, I think the answer to your question is "Why no documentation?" is simple. It is free open source software and the developers didn't yet have to time to do it in more details. However, if you have some knowledge in the subject you can contribute:

https://www.blender.org/manual/about/contribute/index.html

If everyone will do so, the documentation soon will be very extensive.

Second, it is true, that the documentation on this topics is not detailed enough. I also didn't necessarily have problems with particular materials, but wanted first to know what materials I can create, how I should do it and what different parameters mean. I found many answers in the article below. It has good explanations and many pictures. Hope it will be useful for you too.

http://www.blenderguru.com/articles/cycles-shader-encyclopedia/


LookDev mode is intended to give a basic approximation of how the material will behave. Those reflections? They're a built-in environment texture so that we can see the reflections of the surface. Rendering is a different process tho, and uses separate lighting.

Lighting is a pretty complex topic, but one good way to get reliable results is to use an HDRI - like lookdev mode does. Hdris can easily provide good lighting and realistic reflections. This is perfect in your case too, because the reason that the rendered sphere looks flat is because it only has a uniform color to reflect! The best free high-quality HDRI source is hdrihaven.com To learn about how to use them in your scene, see this How can I render an object with an hdr background?

I hope this helps!


Create Realistic Lips Without Sculpting Them From Scratch?

So I actually figured out how to do it. For anyone who might be interested in my process, here goes. I realized that the picture I took of my own lips was a poor quality picture because the lighting was uneven and that caused a lot of bumpiness when I anchored the image on my character in sculpt mode. When I used a picture with even lighting, it automatically looked way better and needed a lot less clean up. To prep this photo, I used Gimp to create a high-quality image for the sculpting brush I created in Blender 2.82.

As far as settings, I used the Clay sculpt brush with the full strength of 1.00, Mapping is set to "Area Plane," Stroke method is set to "Anchored" in the remesh section, Voxel Size is set to 0.1800, and I did have to do some massive clean up for the face, but they were small details that needed to be removed. Lastly, I did need to use the "Crease" brush with "Stabilize Stroke" on with default settings. I also used the "Grab," "Snake Hook," "Nudge," and "Smooth" brushes to get the shape correct and the texture even. Since I have multiple copies of my character saved, I used the original copy of my characters' face as a reference to correct all the facial proportions after the lips texture was finished (Images used as sculpt brushes will slightly change the proportions of the character).

I sculpted to remove details that were incorrect leaving only details that looked pretty decent to me. This is by no means hyper-realistic but that's not my goal. It looks good enough for me and I'm happy with it. I still need to properly color the lips and create a gradient for all the colors, but this picture shows how it turned out. For anyone who only wants to use sculpting to remove unnecessary details without actually having to create the detailed creases of the lips from scratch, this is what worked for me. Hopefully, this helps someone.


How do I align a view to the plane intersecting selected vertices

just rotate the whole loop with R from the side view then grab, move, and scale the whole loop into place.  for the trunk to have a smoother curve, you're going to have to add more edge loops with Cntrl R.

Edit: part of the reason is your topology, i just edited your image a little to give it a more practical topology. you just gotta move your vertices around a little near the mouth and neck area.  take a look at the edited reference image below


A rigging method without physics

To simplify this report, consider only two-dimensional space.
It is also assumed that the lower lever has a smooth convex curve and the upper lever is a straight line on the side where the two levers touch. With this assumption, rigging with Armature was able to solve the problem.

First, for simplicity, coincides the coordinate system of the lower lever object with the Armature space. In other words, only the upper lever slides on the fixed lower lever in the Armature space. This behavior could be realized by using Follow Path and IK constraints. Then, the behavior of bones was transferred to the both lever objects. Finally, the rotating shaft of the upper lever was fixed by using a Copy Rotation constraint.

Armature

Mesh Objects


Why doesn't Connect Vertices create an edge as opposed to Make Edge/Face?

The difference between them is that Connect Vertices tool cuts through already exhisting geometry (just like Knife Tool), whereas Make Edge/Face creates new one.

In the proposed scenario it's hard to see the difference, so to better demonstrate it I used side of the cube.

Connect Vertices

The tool will cut through exhisting geometry based on selected vertices which belong to the same face (so if I selected 3 vertices where one vertice per face, there wouldn't be any effect)

Connect Vertex Path

(I decided to put it also here because for some time I couldn't get the difference)

The result of using Connect Vertex Path command (J). The order of selecting vertices is important; whether vertices belong to the same face is not. The adjacent faces were splitted, becoming tris now.

Make Edge/Face

Make Edge/Face (F) will simply create new face there atop of exhisting one, not splitting anything.


Elliptical Movement of a Ball on a Narrow Edge

Use the Shrinkwrap constraint to automatically move your ball down to the surface of the moving paddle.

Note that the Shrinkwrap constrain includes a 'Distance' property and this can be used to control the distance from the paddle. This will be fine if the target mesh is concave and fairly rounded but can cause the ball to intersect with the mesh for convex or sharp edges.

To address this we can create an additional mesh based on the original one but 'expanded' so the surface is at a specific distance from the original surface.

Duplicate the mesh and add a Solidify modifier. Set the Depth to the radius of the ball - but negative so that the solidify is outside ratehr than inside the mesh. This will produce rather 'square' results so to round the edges add a Bebel modifier prior to solidify. Adjust the bevel on the generated mesh closely match the radius of the ball.

NOTE : Using Solidify in this way will result in geometry of the 'expanded' mesh that exactly coincides with the original mesh. This can cause problems with rendering so it's a good idea to move the faces slightly so as to offset them. To achieve this you can simply amend the Solidify 'offset' by a small amount - eg, -0.98 rather than the default of -1.00.

Optionally add a Subsurf modifier to round any remaining edges.

Finally, use the 'expanded' mesh as the target for the Shrinkwrap constraint on the ball. Parent the 'expanded' mesh to the original so that it moves in unison with it (select the 'expanded' mesh, hold Shift and select the orignal mesh, Ctrl+P, Set Parent to Object).

Now place the ball over the paddle and set up the Shrinkwrap constraint using Project mode in the -Z direction, setting the Target to the 'expanded' mesh. Moving the paddle under the ball should result in the ball following the surface of the paddle.

For added realism you can animate the location and/or rotation (if using Local axis space) of the ball in order to change the position on the paddle and move the paddle (in real life the paddle would need to be moved towards the ball to 'force' it uphill). If animating the rotation of the ball to make it appear to roll on the surface then set the Axis Space to World Space so that the rotation of the ball does not affect the location of the shrinkwrap projection.

Blend file included


You can do it this way:

Create a Circle, shift it from its origin in Edit mode, go back in Object mode, create an Empty on the same point as the origin of the circle. Assign an Array modifier to the Circle with a Count of 5, deactivate Relative Offset, activate Object Offset and choose the Empty. Rotate the Empty 72° on the Z axis. Apply the Array modifier, you now have 5 circles.
Extrude one time your 5 circles and repeat with shift R so that you have several extrudes (of course you can also decide to make all these extrusions, or edge loops creation, on the original circle, before applying the first array).

Assign a Simple Deform modifier to your object, with a Deform Angle of 72°. You can Apply this modifier if you want.

Assign an Array modifier to your Object and choose a factor of 1 on the Z axis. Maybe enable Merge and First/Last so that the top sticks correctly to the bottom of the array copy. Choose the Count you want.

Create a bezier curve, go in Edit mode and make sure the direction is the one you want, if not W > Switch Direction. Put the Origin at its starting point.
Put your object at the beginning of the curve.
Assign a Curve modifier to your object, choose your bezier curve as the Object. It should follow the curve.
You can add a Subdivision Surface modifier to your object and smooth it.


Why does recording an animation not record the initial position of an object?

I think what you are trying to do is 'keyframe'. First select the object you want to animate, press I on your keyboard while your cursor is somewhere in blender viewport and a menu will pop up, select 'LocRotScale' since you are a beginner, ignore the rest.
A yellow diamond symbol will be added on your timeline. (Note it will be hidden if you deselect the object, but not deleted. Select the object again to see it.)
This is called keyframing.


I had the same problem recently. It's probably something else, but, please, try to run blender via CMD (windows+R : CMD). If it's the same issue as me, you could have this error :

  EXCEPTION_ACCESS_VIOLATION

If it's that error : you just have to reinstall blender 2.76b. (It worked for me on my old computer with a windows 10). Somebody here had the same issue and report the bug (I think)

If it's not, you could copy/paste the error here.


Needing help with Vaporwave inspired Illuminated grid (Eevee 2.8)

Eevee currently seems to have issues with the wireframe node, in cycles it seems to be rendering correctly.


UV Editor: unwrapped faces disappear if I select other faces

There are two things going on here:

When you hit U > Unwrap, Blender only unwraps the selected geometry.  To unwrap the head and tail of the mushroom, select them both before unwrapping.
The UV/Image Editor view only shows the pelt[s] for geometry that is selected in the 3D View.  When you deselect something in the 3D view, it's unwrapped texture coordinates aren't deleted, they are just no longer visible in the UV/Image Editor.You can optionally use Sync Selection option so the UV selection matches the 3D view-port. This can be toggled using the button to the right hand side of pivot point popup.


How can I find out how many triangles are in my model?

Select your object, and go into edit mode (Tab). In the info bar it will say how many triangles are in your object.

In object mode it will tell you how many triangles you have in the current layer(s).


How to model a ridged dial or gear shape

There are at least three methods for accomplishing this. Each is worth familiarizing yourself with.

The Cylinder Method

1. Create a cylinder

ShiftA

Add > Mesh > Cylinder

Adjust the proportions and vertex count to your liking.

2. In Edit Mode Select Edge Rings

Set your selection mode to Edge Select.
Select an edge, then while pressing CtrlAlt select the edge next to it. Alternatively you can use the menu: Select > Edge Rings.

3. Bevel the edge rings

CtrlB

Use cursor distance to adjust bevel width, then left click to accept.

4. Extrude the faces

Set your Pivot Point to "Individual Origins".

Press E to Extrude to your desired length.

5. Scale as needed

While still using "Individual Origins" as the Pivot Point, press S then ShiftZ to Scale the angle of the teeth. Scale the height using S, Z.

The Add-On Method

1. Enable the Extra Objects Mesh add-on.

There are two add-ons for Extra Objects, one for curves and one for meshes. The one that applies in this case is the one for meshes. Go to Blender's Preferences, search "extra", and click the check box to enable it.

2. Add a Gear

Press ShiftA and find a new option in your Add > Mesh menu: "Gears". Add one.

3. Tweak the gear parameters

The add-on provides many parameters for fine-tuning the shape of your gear. Play with it!

The Circular Array Method

1. Add a plane and model it into the shape of a gear tooth

ShiftA Add > Mesh > Plane

The plane is just a starter shape.

Model the shape of a single gear tooth in Edit Mode.

Make sure the Object's Origin Point is where you want the center of your gear to be.

2. Add and rotate an Empty

ShiftA Add > Empty > Plain Axes

From Object Mode, press R and type in 15 to rotate it 15 degrees. We can change this value later, it's just an example.

3. Add an Array Modifier to your gear tooth object

Modifier settings:

Uncheck "Relative Offset". Instead, check "Object Offset" and point it to your Empty.

Since we rotated the tooth 15° in this example, set the Count to 24 to start. The dimensions of your gear tooth object also come into play here, so you'll need to do some adjusting of these three factors: tooth count, rotation angle, and tooth geometry.

Check "Merge" and "First Last" so that you won't need to remove doubles later. This option merges the doubled-up vertices for you.

4. Close the loop

Set your snapping method to Vertex Snapping.

On the modifier, adjust the edit cage to the modifier result so the array geometry can be snapped to. In simple English: click the fourth button.

You can now extrude another vertex and snap it to the next tooth in the array. Fill in a face between this and the vertex in the center of the gear. The circle is now complete.

Here is a screen shot to further illustrate how one segment is used to create the entire gear:

5. Add some thickness

Finally, add a Solidify Modifier and give your gear some Thickness.


Here is how I made it work. I had to flash the bios. If you are like me playing with the settings all the time you need to reset the bios by taking out the little round battery on the mobo. Depending on your mobo, the flash reset button next to the usb slots on the mobo didn't work for me, it might work for you. After that blender will open and both cards are seen in Cuda and Optix. Indeed there is some work but I'm pretty happy with the result right now. However render time is not cut in half though. More like 35% less with two cards.


Blender 2.8 Displacement node not working

The displacement is too weak, you're seeing it in the others because of the scale of the object.
Apply the scale (alt+A) in any mesh that it worked that you will see that the displacement effect is gone.
In the same way, press S+Z in the mesh of the pic and you will see the displacement
And you also need to be in Cycles "rendered" view to see it. The Shading preview will always use Eevee


Get the ICE shader (procedural) from here:

https://gumroad.com/trapanidigitaldesign

Bake textures to use them as PBR.
Done.


In the Displace Modifier panel enable the option Display modifier in Edit mode.