text:
How to edit a duplicated animation?
I've followed this question because I want to split an animation into run/walk/attack.
I've entered the dope sheet, duplicated the animation (and pressed the F) and renamed them appropriately. But since I'm very n00b, I don't know how to set the starting time position for each animation...
[EDIT] The original animation is run, then walk, then attack. I want it to turn into 3 different animations. Right now I have 3 duplicates of the run, walk, attack; I'd like, for example, to cut out the "run" and the "attack" from the "walk" animation.

Could you add more detail, I can't figure out what you're asking. If you need to move key frames, try the G key.

I assume you're going to be using NLAs.
Since I've been unable to find a good explanation of blender's NLAs, I've decided to write a bad one and hope that feedback lets me improve it over time:
https://docs.google.com/document/d/1WrrdFpZ-VC7taxu4iD3hZIowYvyM953iZpBwkZ78PgA
I will include a (soon-to-be-outdated) copy of the "splitting actions" section here:

This is probably the most difficult of the workflows.  When you are
  starting out with NLAs and haven't become comfortable creating small
  reusable chunks you will often realize "I wish I had split this up
  before now."
The essence of splitting is to create a copy and delete part from
  each.  Let's refer to those two parts as A and B.
Imagine your action is currently the primary action.  Use the Dope
  Sheet/Action Editor to give it a "good" name (maybe "AplusB").  Then
  use the double-down-chevron to move it into an action strip.  Create a
  new track and create a new action strip in that new track that refers
  to the same action.   You now have two action strips referring to the
  same action datablock.  Go ahead and create a third action strip
  referring to the same action datablock as a sort of information bunker
  in case you make a mistake later on.
Make one of the strips active and hit the Tab key to start editing it.
  Use the Dope Sheet/Action Editor to make a single-user copy of the
  action (click the [3] button).  Now give it a name that identifies
  which half of the action it will become (maybe "part B").  After that,
  you can delete all the keyframes that don't belong in the action
  (delete the A, leave the B).    Memorize the name of the new action.  Hit Tab to stop editing that action strip.  Now change the Action of the action strip  to refer to the new action.
Make the other strip active and hit the Tab key to start editing it.
  Use the Dope Sheet/Action Editor to make another single-user copy copy
  of the datablock (click the [2] button).  You can rename it (maybe
  "part A").  You can now use the Graph Editor to remove all the B
  keyframes and leave the A keyframes.  Don't forget to point the strip at the new action.
Before you test the animation you should discard the 3rd (information
  bunker) action strip but not before you click the [f] button to force
  blender to not garbage-collect the AplusB action.  That way you can
  still recover it later if you find problems with the animation.

The action editor is the easiest place to re-time your animations. After you have duplicated the action and deleted the other parts, you can select all keyframes A and move them along the timeline by pressing G, like moving anything else, until the first keyframe of the new action is at frame one.
In the dopesheet header you will find a snapping options menu, having this on Nearest Frame helps to keep things aligned.

Using this answer I put together an addon to make it easier to use. If you save your startup file with the addon activated it will always be there.


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How can I stamp a texture on top of a material?
I have a material that covers my model in camouflage. Now I want to stamp a regular old UV texture on top of that material, in such a way that transparencies in the texture show the material. Say I want to stamp a large letter "A" on top of the camo; the A only takes up the corner of the face, and the material should still how through the middle gap of the A.

https://www.youtube.com/watch?v=nhOPvj1DbVQ here is a tutorial on how to add decals to models

Thanks @NascentSpace, the comments on that video led me to this one which is much easier and works perfectly for me: https://www.youtube.com/watch?v=QGxMY2lMoLw

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


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Why does my material only render correctly on certain faces?
I have been getting started with materials and wanted to create a lo-fi scene with a dark marble material. I followed a tutorial to create the marble material, which works great. I then modified it using another tutorial to make it look more pixelated and retro. Here's the node graph:

And the preview looks like exactly what I want:

However, when I apply it to faces in my scene only some of them render the material correctly. Others distort the material into strange angles:

The faces marked with a green dot are rendered correctly, those marked with a red dot are inexplicably distorted. It works just fine if I use the more realistic material by disconnecting the snap node from the bottom voronoi node. This happens in both Eevee and Cycles, in previews and final renders. What gives?

Hello :). You're using Generated coordinates. Those cause stretching on anything else than 1:1:1 cube :)

@JachymMichal Ah, is that so? Is there a better way to pixelate a material, then?

Your material is fine :) Just use UV coordinates for the other Voronoi and Noise textures too. That way you'll have the best control and can avoid stretching.

You’re using UV coordinates to sample your Voronoi texture. This is fine, but the default UV map will not automatically compensate for stretching/scaling of the model. To illustrate, I took a cube and shrunk it along one axis:

Note how in the UV map, all six faces are still squares of equal area, even though they aren’t on the model.
Fortunately, all you need to do to fix this is to re-unwrap the mesh. If you don’t care about continuity between the faces at all, you can do the simplest thing of marking all edges as seams by selecting the whole mesh with A, then CtrlE ▸ Mark Seam. Then you can do U ▸ Unwrap, which will automatically compensate for face size:

As you can see, this fixes the texture stretching.

Thank you, this is exactly what I needed.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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How can I align vertices to an axis?
I'm not sure how to ask this question. Basically, I built a part in the right half of my screen, looking at it from the Y perspective (numpad 1). I applied a mirror modifier, across the X axis. I left a gap in the middle so that I could more easily create the part. Now I want to scoot the part along the X axis so that there is no gap in the middle. I know how to move the whole part together, but how can I move it so that the leftmost vertices are exactly stuck together, completely eliminating the gap?

Check out "Clipping" in the mirror moddifier. Then see what happens when you move the parts together.

That's pretty close to what I want, but how can I snap the grab to the mirrored vertex so that I can be absolutely sure that the parts have zero space between them and retain their original size?

It's annoying that, in Edit Mode, Blender's Snap To : Increment doesn't have a Snap With option, otherwise this would be more intuitive.
In this case, if you have the shipped add-on  '3D View: Pie Menus' activated with the 'Origins' option, you can quickly set the origin of your object to the vertices of the desired mirror-plane from Edit Mode, and the mirrored half will jump to the original. Then you can AltG reset the object back to World 0.
But personally, rather than puzzle over each case, for more CAD-like snapping, my habit is to create temporary snap targets.

With snapping nearly always set to To : Vertex and With : Active, and the pivot set to 3D Cursor:

ShiftDX duplicate a single vertex..
SX0 scale the vertex to 0
Select the source vertex, (it will stay active), and L all the connected ones
GX Move the selected vertices, snapping to the temporary target
Delete, or merge, the target.

I wouldn't claim this is necessarily the quickest for this case, but the method is quite general. You can leave your pivot and snap settings as they are over most operations, and the sequence goes into muscle-memory.

Thank you, this is more or less exactly what I needed. I don't mind if it's a little slow, as long as it's generally applicable. My only question: how did you use scale to set the vertex's X to 0? When I did that, nothing happened. I just edited the position of the vertex manually.

Hi @alskdjfoijowiejf ! (thank God I don't have to type that :) )    With the pivot set to '3D Cursor', and the cursor at 0, SX0 should do the trick. Actually, you could: Shift-D,S-X-0, all in one. but my muscles don't remember that much :D.

In edit mode select a vertex to the left of your model press N to see the "Item"->"Transform" panel. Select "Global" and copy values from X field.

Tab out of edit mode and in same panel subtract the copied X value from current object location.

This moves the object to the left by exactly the amount needed to put the vertex you selected at the very beginning on the X = 0.

Sometime it doesn't work perfectly, and slight adjustment at the very end is necessary.


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PNG with alpha casting strange shadows depending on viewing angle (Blender 2.91.0)
I have a RGBA png and i want to render it infront of a plane, but when i do, it casts weird shadows on the plane, the strange part is that the shadows only exist and change under certain viewing angles. video below for reference
I have tried changing shadow setting but so far i really dont know how to fix this problem
im renering in cycles
Reference YT Video Here

Please do not use videos in the question. Use the direct image adding system. It’s considered online protocol not to follow YouTube links you’re not sure of the destination of.

Instead of having users go through links and external sites please use the builtin tools to embed images in your post. See How to upload an image to a post?

Also: From that video I can't tell what the problem is.


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Computer stuck on fluid baking
I am trying to bake a fluid simulation of 1.45GB and my pc is stuck and stopped responding. What can I do? Will it help to increase my RAM amount to 16GB?
System specs:

Windows 10 Pro Insider Preview 64-bit
CPU - Intel Core i7 4770 @ 3.40GHz39 °C , Haswell 22nm Technology
RAM - 8.00GB Dual-Channel DDR3 @ 798MHz (11-11-11-28)
Motherboard - Gigabyte Technology Co., Ltd. H81M-S2PV (SOCKET 0) 28 °C
Graphics:

L1953TR (1280x1024@60Hz)
W2242 (1680x1050@60Hz)
SyncMaster (1280x1024@60Hz)
Intel HD Graphics 4600 (Gigabyte)
2047MB NVIDIA GeForce GTX 1050 (MSI) 33 °C

Storage:

111GB Corsair Force LS SSD (SSD)    30 °C
931GB TOSHIBA DT01ACA100 (SATA) 34 °C

OMG 1.45 GB.Dude that's quite huge than what your machine could handle smoothly.That's the problem.Try decreasing the resolution of fluid.What exactly are you doing? Not trying to simulate an ocean or huge lake :-p .16 Gb probably won't handle that huge fluid smoothly either.Try to decrease the fluid size.

I don't understand why 16GB is not enough, why 1.45GB RAM is not enough?

Because 1.45 GB of fluid simply means way too high number of vertices to handle for a computer even with 16Gb RAM.Don't believe me go ahead and select your domain and take a look at the top right hand side for vertices.You probably have close to a million vertices.

Thanks, I need to upload it to sheepit(render farm) and the size limit is 500MB, so I decrease the size to 400MB. It's work smoothly now.

yeah that's perfect size for your computer.smooth sailing man :)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Why are node groups not being saved in my startup file?
I made four node groups in blender and saved the blender file to my hard drive. I want these node groups to appear every time I start Blender, so I do have not append them every time I need them. So I opened up a new blender file, clicked on "append" and appended all of the node groups from other blender file. I click on save start-up file and exit. When I open blender again, the node groups appear but not all of them. Only one or two. if I append the missing node group again, and save it again, the next time I open up blender all node groups are gone. It is like random.
Am I doing something wrong or something is broken with blender?

have you set a fake user on the node groups before saving the startup file?

Node groups have users linked to them, like materials or textures. If a node group has no user, it will not be saved to the blend file. After startup they will be gone. In some cases it takes more than one restart and save before all unused instances are gone due to internal dependancies.
You could, as aliasguru suggested, set fake users. This could be done by executing this line in the python console:
for node_group in bpy.data.node_groups: node_group.use_fake_user=True

Afterwards they should not disappear anymore. Note that you have to repeat it for every file and when you create new node groups.

Any other way to do this beside python? I have no clue about python console. And you did not tell me if I should type in those lines exactly or how.

@4-K: It works straight forward. Copy the code line in my post. Then open a Python Console Window in Blender. Hover the cursor inside, so it is the active window. Paste the line with crtl+v if you use windows. Press enter two times. Then you can save your file and close the console window forever. You won't need it anymore

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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"no objects or images to bake to " even when texture and object are active
The "no objects or images to bake to" error I get when I try to bake. As you can see below it happens to only some objects even though the texture appears active.

Internal uses face textures to bake images..image shown in UV/Image editor in Object mode doesn't mean it's active for selected object. So most likely cupboard has image assigned to its faces.. while object on the right hasn't. Checking that is done in Edit mode with all faces selected - if image is shown in UV/Image editor then it's assigned.

I went to edit mode, made sure all face selected , re-selected the image in UV/image texture and even tried baking in edit mode but still the same error.

It works as I already mentioned. Aside from that before re-selecting image in UV editor select all uv islands and then remove image and assign it back.


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What is the 3rd option in an enum property for?
If I look here I see the following:
https://www.blender.org/api/blender_python_api_2_66_4/bpy.props.html#get-set-example
# Enum property.
# Note: the getter/setter callback must use integer identifiers!
test_items = [
    ("RED", "Red", "", 1),
    ("GREEN", "Red", "", 2),
    ("BLUE", "Red", "", 3),
    ("YELLOW", "Red", "", 4),
    ]

What is the "" field for?

From the documentation you linked:

items (sequence of string tuples or a function) – sequence of enum items formatted: [(identifier, name, description, icon, number),
  ...] where the identifier is used for python access and other values
  are used for the interface.

The third item is therefore the description, which is used for the interface.

no problem, we have all done that!


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How to save a scene setup with a named label (multiple renders from single file)?

I have a file with 10 objects in it
I want to produce 5 different renders from this file
Each render should have its own camera angle and light
Each render may have the objects differently arranged/moved
I should be able to switch between each render I want to produce by clicking on a name of it in a list, and cameras, lights, object placement/visibility should follow.

Is this possible to accomplish in a single file in Blender?

Two ways that come to mind.

Separate Collection for each setup. Uses the same render settings.
Different Scene for each setup. You can set up different render settings for each scene.

Using Collections. One click to enable, second click to set camera as active.

Using Scenes. Change your setup and active camera with one click.


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How to create vacuum packaging?
I am trying to figure out, how vacuum packed sausages can be done in blender. The one you can buy in every grocery.
The sausages are not the problem, but the plastic packaging outside, which is normally really tight to its content
My first thought was to do it with a cloth simulation, letting a sheet falling down on it so the contours get visible. That will not work, because ... yeah it just looks like what it is... a sheet falling down on a couple of sausages...
The second thought was to use the shrink wrap modifier but that also will not work. If place a square under and over the sausages, the modifier only stretches the sheet also over the little gaps between the sausages. That doesn't look like accurate.
Is there maybe a way to let the content be a force to the surrounding package?
Its a bit complicated. The package behaves not quite like a second skin. You can see the plastic making an arc from one sausage to another but sticks very close to the content ...
Any other ideas?

Could you provide some images showing what you want to achieve? There are too many different packaging options out there.

On the left, a shrinkwrap modifier is used, and this is both shrinkwrap and cloth simulation on the right.

The left one

It is a UV sphere, rotated so that the poles are at the sausages extremities, scale to be close to the target and subdivided in order to fit the target more accurately. The idea is to create a surrounding shape so that it helps the modifier to project the vertices correctly.
Then a shrinkwrap with a little offset and set to 'nearest surface point'.
As you can see below, the gap between the two sausages is composed of stretches faces.

The right one

It uses both shrinkwrap and cloth simulation.
The shrinkwrap is this time set to 'project' and uses a vertex group: here we want to shrink/project only the needed parts:

The shrinkwrap is only here in order to level up some part of the mesh as if not the flat film may cut the sausages. But you can also sculpt/shift it up manually to avoid the modifier.
The cloth simulation uses a pin group and sausages are collision object:

After animation we obtain this shape:

Though, the blend file here uses Cycles and not Blender Render (as I don't know it enough). But I think the question was mainly about the film's shape.

This is exactly what i was looking for! Many thanks. I'll try it

How come this does not have like a fricking billion upvotes? Man HUGE thanks for the time you've put into this!

Hey if I may ask, what's the mode you use that looks like UV heat vision? And why do you use it?

@cubrman, weight paint mode (ctrl+tab from object mode)


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How to create spiral in blender?
I have attach 2 images of what I'm trying to achieve...

I would like to know how to do this stuff by nodes or by random faces selection... I tried inset faces and rotate some vertice but that doesn't seem to work...

You mean a spiral mesh or a procedural texture?

First spiral done with nodes: https://blender.stackexchange.com/q/107656/78972. Second spiral using nodes: https://blender.stackexchange.com/q/166707/78972


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Undo suddenly stopped working 2.79b
I was working on a project in the VSE and editing some keyframes via the graph editor. I believe I used key: Mirror as my last known command because I was trying to invert the keyframe positions. It didn't work, the keyframe became a solid line and moved downwards for some reason, I went to undo and undo didn't work.
I've spent another 30 minutes in the project thinking it would fix itself, it didn't. I restarted the project still not working.
Looked online, tried shift+alt and shift+w but there was no change or any indication that keyboard change was the cause. I'm using qwerty and it's supposed to be control+z to undo and control+shift+z to redo as its always been. Checking controls it indeed still is. Under undo steps they had been set to 42 a while back and global was always on. I moved them to a lower value, no change. Keyboard is set to the same language its always been in the windows tray. I'm at a loss here on what happened or how to fix it. Only remaining thing I can think of is to mess around with the graph editor and see if that jogs it, perhaps a bug with the mirror options, perhaps it was an earlier operation or a bad strip in the vse?
This is rather upsetting as I still have a fair amount of work left to do on the project, mainly the finishing touches and filters and special effects, and those are the ones you need undo the most for.

As far as you restarted the project your undo history should be gone... Does your undo history still work? There is a menu entry for it, I don't remember where exactly... And see in your settings if your CTRL-Z shortcut has been assigned multiple times, maybe you set another keyboard shortcut by accident in the graph editor.

(Elaborated from Samoth comment) opening the history Ctrl Alt Z. Do you see items in this dialog?

Somehow I changed to edit mode in the 3d editor, I don't know how given I was only using the vse, but changing back to object mode fixed the problem.


text:
Create blocking popup in Blender api
I'm writing an addon to import game models into Blender. But sometimes, there is a mismatch between a bone's name from the animation file and the name from the object file.
So I'd like, when the script encounters an unknown bone, to open a popup with a list of existing bones (plus an option to ignore the bone), that would pause the script until the user has chosen his result, and to get back the chosen option.
I've seen
How to call invoke_popup?
to create a popup, but I'm stuck on several points :

how to call it from my python code
how to change its name (label) before calling it (to say for example "bone X not found")
how to get the result of the selection
how to get the user see and interact with the popup before the end of the script

invoke_popup() is not really reliable for your use case. You should better use a regular panel, because the user can't dismiss it like a popup (they are not really blocking in Blender).

Thanks for the advice. I never used panels in scripting. Do you have a link to a tutorial to create this kind of panel?

Here are 3 resources: http://wiki.blender.org/index.php/Dev:2.5/Py/Scripts/Cookbook/Panels_and_Operators/Ping_Pong http://wiki.blender.org/index.php/Dev:2.5/Py/Scripts/Cookbook/Code_snippets/Interface http://www.blender.org/documentation/blender_python_api_2_71_release/bpy.types.Panel.html#basic-panel-example

Yes, Python can make a popup menu.
The options are either...

Create a popup on the fly. using bpy.context.window_manager.popup_menuhttp://www.blender.org/api/blender_python_api_2_75_release/bpy.types.WindowManager.html#bpy.types.WindowManager.popup_menu
Define a menu subclass of bpy.types.Menu, then call it. see:http://www.blender.org/api/blender_python_api_2_75_release/bpy.types.Menu.html

Both of the links above include examples.

Regarding "How to get the result of the selection", The way Blender works, menu items reference operators. So you would need to define an operator which is referenced from the menu.


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How to get rid of imperfections after applying subsurf?
I'm trying to model a simple sofa in blender but after I applied subdivision surface modifier i got that nasty gap. On the other side it looks good.

here ^ is how it looks in edit mode, there are not two objects but one so moving the small part in won't do.
PS: no need for elaborate stuff since I'm using it only as a prop, it was not intended to be a high quality object in the first place, so any solutions will do (even if it's not 'by the book'). Thank you!

Can you post a .blend?

Try selecting various edges and apply mean crease: Shift-E

Thanks for the advice! I managed to re-create that edge loop and I was more careful not to go too far with it, so it's fixed I think.

I managed to solve it!
I deleted the vertical edge loop (Alt + RMB) then X → Edge Loop
Then Ctrl + R to make another vertical loop cut and I was more careful not to slide it as far.
This is how it looks now

This is how it looks in the edit mode with the new edge loop

I don't know if it's the right thing to do but it worked for me!


text:
Wireframe modifier resolution
Basically I am asking what was already asked a year ago in this thread:
Create a rounded wireframe?
The question is basically unresolved an I thought that since a year ago someone might have an answer, or simply an idea about how should I go about doing this in my own case. The wireframe + subsurf technique, even with with a crease of 1.0, will create uneven thickness with pointy corners at the vertices, however much I play with the options, and also subsurf adds unnecessary edge loops, subdividing edges between vertices.
What I feel would solve the problem is a RESOLUTION option in the wireframe modifier in order to turn those 4-sided wire frames into cylinders. Just like the option you have with curves. I know you can convert the mesh to curve but that automatically results in disconnected topology. And the skin modifier is way too heavy and results in twisted topology as well as rounded intersections.

In more practical terms, here is what I want to achieve. I have this mesh you can see in the picture above, which is actually a floor. Everywhere you see edges, I would like to turn them into cylinders in order to make a nice pattern onto what is an otherwise quite boring floor. I could of course use a texture but I would like the pattern to be 3 dimensional, and a 4-sided wireframe just doesn't make it. It needs to be round. What would be the most efficient way to do this, without the ugly results of the wireframe+subsurf, skin, or curves?

What about deleting faces only, turning into a curve, adding subserf, and then play with it from there? EDIT: Okay, never mind, blender doesn't like that method :(

possible duplicate of Create a rounded wireframe?

@RayMairlot Indeed this question is already linked in mine. I am saying no solution was found to it and I'm asking input on my specific case.

@cegaton You are right, though the wording of the first two paragraphs doesn't help. It makes it sound like the question is simply re-asking a question from a year ago, whereas the later paragraphs explain this specific use case.

I have retracted the close vote, but I would personally move the last paragraph and image to the top to focus this on your specific problem. The opening paragraph makes it sound like you are purely re-asking an existing question. While I did read it all, that opening swayed me to think it was a duplicate. Just my opinion though.

I'd suggest using TARDIS Maker's solution, but instead adding subsurf, turn on beveling that curve either with using bevel object or simply by increasing Bevel's Resolution and Depth - http://i.imgur.com/VzNAzWV.jpg

@MrZak As previously stated in the question, the problem with a curve is that even though the bevel gives you the exact controls on the shape of the cylinder, if you look closely at certain intersections, you will find distortion and mostly disconnected topology, because a curve is basically a path with a unique direction.

What about adding a wireframe modifier, than adding a bevel modifier, and using the angle in the bevel modifier so that not all of the edges are beveled, and playing with the bevel values?

@TARDISMaker That is a very good idea I hadn't thought of, and seemed like to be the solution at first, but I tried it and I cannot limit the bevel by angle, because the wireframe mod does not make tubes with 4x 90 degrees angles as I thought. I'm not sure if this is a bug, but depending on the edges being wireframed, some of them present an irregular quad cross-section. And then even if it did make perfectly square tubes, the angle mode works with a minimum, not an absolute value, which would inevitably bevel other parts above that value.

I too am still interested in finding a nicer solution :) Perhaps a feature request is in order..

You can use a sub-division surface modifier on top of a wireframe modifier. The trick is to enable 'Crease Edges' in order to maintain the crease in edges you don't want the subdiv to smooth out.
It should look like this:

As previously stated in the question linked, the comments and the question itself, wireframe+subsurf and crease does not give appropriate results. You can see it in your screenshot: the radius of the cylinder is not constant. The intersection points have a bigger radius, which gives "pointy corners" at the place where the original vertex were.

Select green edge loop Alt+RMB, Ctrl+E > Edge rings, Split (Y), Hide (H)
Select blue edge loop Alt+RMB, Ctrl+E > Edge rings, Split (Y), Hide (H)
Select all (A), delete all vertices X, unhide vertices(Alt+H)
Back to Object Mode (Tab), Curve from mesh (Alt+C)

Set Curve 3d fill to full and set bevel depth and resolution:

Interesting idea. So far one of the best, but still not exactly what I am looking for. Issues: 1) Disconnected topo. Here it is done on purpose so that we are left with a consistent result instead of one single and very long curve, but inside faces remain and the object is not manifold. 2) For the first time trying this, the angles/intersection are looking great. However, it does so at the expense of a "flattened" (ellipse) tube rather than a circular one. There seems to be no way around this, because it's impossible to specify a separate X and Y value for a "width" of a curve control point.

Thanks for the interesting idea though!

You will need to install standard add on "Extra objects">> "block tools">> "struts". This is what you need un a simple way.


text:
Recreating gloss from older version of Blender
I am using Blender 2.92.0 and learning from the Andrew Price earth tutorial in Blender 2.76.

Using the same steps, my lighting and/or material looks significantly different:

Notice that the scattering seems different, like the roughness of the surface or the intensity of the lighting does not match up. Andrew's has a distinctive haze around the edge. I can get a more similar effect by increasing the Glossy BSDF roughness to 0.36 and giving the sun a slightly different angle, as shown below, but I'm just curious about the possible cause of the difference?

Here's the setup for the original images above:

I redid the first few minutes of the tutorial twice to make sure I hadn't missed anything.
In general, do shader setups tend to produce different results across different versions of Blender? In other words, is there some sort of "hidden state" that does not carry over, either due to rendering engine changes or modifications to the shader components themselves?
Thanks!

Yeah it's possible that the distribution function you're using differs, or some changes in cycles make this the case.  If you want to be sure, you can grab the old version of blender and recreate it.

Or it could be filmic color transform, I suppose

Thanks for the suggestions. I downloaded Blender 2.76 and the gloss looked more natural / smooth right away. Oddly if I switch my color transform from Filmic to Standard in the newer Blender, it becomes even more off, and I have to increase the Roughness to ~0.4 to get a better approximation of the default 0.2 value in v2.76.


text:
What is the best Blender Python API reference?
I keep happening across information that seems blatantly wrong, and it makes me wonder if error messages are terrible or if it's the documentation.  Here's an example:

However, while the script runs you may want to access the updated values.
This can be done by calling bpy.types.Scene.update after modifying values which recalculates all data that is tagged to be updated.

This is quoted from the "Gotchas" page.
Upon following that advice...

AttributeError: type object 'Scene' has no attribute 'update'

Just to be clear, the documentation authors seem pretty convinced that it does.
Most of the bad information I've found so far comes from forum posts some place where a user just guessed at how to do something off the top of their head.  However, the official docs aren't really helpful for practical tasks, and seem to have bad information lurking about as well.

types is only used for documentation. See this page Also, the 2.62 docs are pretty old by now. This link always redirects to the latest version.

Excellent!  Thank you very much.  If you post that as an answer, I can uptick it so others see it more easily.  Learning Python through the Blender API can be confusing due to the abundance of old documentation out there.

The types module is only used for documentation.
See this page for tips on finding actual datapaths.
Make sure you are using the latest API documentation too, see Where can the latest API documentation be found?


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Where has the "Show in Viewport" option in the 2.8 branch of Animation-Nodes gone?
I may be missing something, but the "Show in the Viewport" option that was available under "Advanced Node Setting" for an input data, is no longer there.
Is there a way to get the data input interact at the viewport level?

There is Viewport Input node to get the viewport inputs and inputs are available in the 3D viewport in N-panel under "AN" option.

This option has been replaced by a more advanced node called the Viweport Input node. Every Viweport Input node creates an input box in the AN panel, the name of the input box is defined by the label of the Viweport Input node that defines it. The boxes can be minimized and you can change the order of inputs as you wish from the N menu. For instance, we have here two Viweport Input nodes defining two input boxes:

Huge Thanks Omar.  Your answer solve the issue.  Gil

@ISNBLENDER Please accept the answer if it answers your question.


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Can Blender be used for 3D reconstructions of CT and MRI scans?
I would like to know if Blender can be used for 3d reconstruction of CT scans and MRI scans etc.
If so, I would like to be directed to a resource that demonstrates this.
I would like to reconstruct 3D images of various organs of the body based on radiological scans, to also illustrate certain pathologies, for educational purposes.

Thank you Ray Mairlot, for the correction.

See also https://blender.stackexchange.com/questions/18418/cycles-volume-rendering-3d-image-texture-ct-or-mr-dataset?noredirect=1&lq=1

@sazarec thank you for pointing that out and directing me accordingly.
Unfortunately, it doesn't seem to be what I had expected. I was thinking along the lines of what Invesalius does.


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How to change the Quick Favorites key in Blender 2.80 Beta?
Today I started using a newer version of Blender 2.80 and they changed the quick favorites key binding from q to ^. While this in itself is okay, I'd still like to change that back.
But I can not find the key binding option for Quick Favorites in the keymaper in the preferences. Is this hard coded? Is this a bug?
How can I change that back?
Thanks already!

A friend found it:
You can find it in the keymapping under Window / Call Menu. The name is SCREEN_MT_user_menu

Menu: Edit -> Preferences -> Keymap choose Window - there's Quick Favorites.

You can always use search to find what you need.

You simply click on the option in the menu with the right button and then on Add to Quick Favourites.


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blender 2.8 grease pencil channel not visible in viewport
I was animating two different characters in each of its channel using grease pencil in blender 2.8.
suddenly I got stuck in the following issues:

I am unable to change or select between channels and draw new frames.
One of the channels is not visible in the viewport or in dopesheet, but I can see in the "view layer" panel under scene collections.
In the object data of the grease pencil channel it shows"multi user data block not supported".

Did you by any chance create a new scene? Because I had problems with grease pencil when I create a new scene (at least as a full copy, haven't tried other scenarios).

i was using grease pencil on a 3d environment. so, yes i created a seperate scene collection(animation)  for grease pencil.

Are you sure you mean a scene? Sounds you're talking about workspace (animation). In my case, if I create a new scene, and in object mode switch to another object, I wouldn't be able to select the grease pencil object anymore, I believe grease pencil (as many other features) are still under development. Expect to find lots of bugs when working with Blender 2.8, since it's still in Beta.

yes, in my case its the same scene . Also in the animation workspace, Im unable to switch between grease pencil channels(i guess, i'm not sure). i drew  around 90 frames  in one of the two grease pencil channel. all of the them are gone. when i select the channel  in the "view layer " panel. it shows "multi-user data not supported" under the object data->onion skin option in properties panel. how retrive the lost frames.  because i can see the layer in the view layers.


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Is blender good for real physics simulations?
I want to make some simulations which present some real physics problems like box sliding from slope with friction. Does blender use real physics rights to animate simulations or is it only approximation?

All physics simulations are approximations :-)
It just depends on how accurate you need it to be. As for your example, a box sliding on a slope is in reality quite complex. You do not only have imperfect, uneven surfaces, but they will also deform under load, maybe even be wet in places, they will possibly abrade and so on.
Depending on the level of accuracy you need, you can either use the fast but somewhat inaccurate blender physics, some third-party multibody simulation tool, or even a full FEM-analysis.
In any way, there are possibilities to use blender for visualization of the results afterwards.
Maybe just describe a little more in detail, what physical effects you want to show and then someone can point you in the right direction!


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Textures always show up in pink
I am really new to Blender, and by the title I mean that when importing/creating a new texture, blender always says that there are missing textures, I have succeeded in painting/importing textures on this same file before, but now it's not working anymore. I have tried the report and find missing files feature, but that does nothing. Any help would be appreciated.

Are the textures in the same place as your model? Have you tried going into 'Material Properties' manually creating a new texture, opening your texture and then applying it to the model? If that doesn't work then maybe go into 'Edit Mode' select all the faces and choose 'assign' in the Material Properties?

Select your object and go to the shader editor, add an image texture by pressing shift>A and then connect the image texture node into the base color. In the image texture node press open and select your file or just open the dropdown menu and select the file from there. Now go to the texture paint workspace and check. It will not be pink.

thanks! it works like a charm


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How can I have multiple separate texture maps for separate objects? Is it possible?
I'm new to blender and trying to model a character, but I still don't have a full understanding of UV maps and texturing yet. He's got quite a few parts, so I was doing my best to fit everything onto the one UV map, but I decided to separate a couple of parts of him - namely his ears and wings - so that I could texture those separately, without having to fit them onto the main UV map. Here's my workspace.

I've done extensive googling but still can't figure out the answer to my question - Can I actually have separate textures/UV maps for separate objects? To be clear as possible, I have most of his mesh in an object called HeadBody. I put his ears and wings into another object called EarsWings. I want to texture each separately, but every way that I try to, even when adding a new UV map, it just ends up on the same crowded UV map again when I go into Texture Paint mode. I read a few things about assigning different Materials, but I couldn't figure out how to assign a texture to those Materials.
Any enlightenment is super appreciated. Thank you!

Yes, it's possible. If you have the wings and ears in a separate object, just create a new material, and select there the image texture you want.
The relationship is the following: Object → Mesh → Material → UVMap → Image Texture.

A mesh can have more than 1 material. In the Edit mode you can select faces and assign them to a material in the material tab.

In the Image Editor you can select the texture images to inspect them or paint on them.

In the Texture Editor, the UV map and the texture are specified in the Texture Slot settings. Blender can read this pair from the material or you can specify the there. This defines on which image and where the pixels go when you paint on the 3D model, and vice versa.

In the Shader Editor you can define with nodes the UV Map and the Image Texture that a material uses.

And in the Object Data Properties > UV maps you can select the active (default) UV map for the viewport and for the render.


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How to control the particular value of the different mapping nodes

So I want to control the rotation of y axis of both the mapping nodes using a single value/node in such a manner that for every increase in 1 degree in the first mapping node ( the above node) the second mapping node(the below one)shall increase by 90 degree.
Is it possible by using nodes/drivers??

You can use this node setup :

The input value (in degrees) is converted to radians then mapped to the Z value of a XYZ Vector. Then it's plugged into one of the mapping nodes on one side, and scaled on the other side then plugged in the other mapping node.

Nice neat solution - and good use of the Scale node. The original question mentioned the Y axis instead of Z, but obviously it's just a minor change to the connection to the Combine XYZ node to achieve that (so just mentioning for completeness).

@RichSedman Oh, right, didn't see that :) Thansk for pointing it out

One solution is to add a value node (Add -> Input -> Value) and a math node (Add -> Converter -> Math). You set the math node to multiply, set one of the values to 90 and plug the value of the value node into the other. Then plug the output of the math node to the second mapping node and the value of the value node directly to your first mapping node. The value of the value node will then control both your mapping nodes.
You are also correct in that you can use drivers for this and that might be better solution. What you need to do is add a driver to the second mapping node value. You can do that by right clicking on the value and selecting add driver. The field should now be purple. Right click again and select edit driver. At the bottom select show in drivers editor. This should open a new window with drivers editor. Alternatively, you can split one of your panes and open drivers editor there. On the left side you can see all your drivers. Navigate to this one. If you don't see them, make sure the little arrow option on the top which says "only show selected" is off. Now you shoud see something like this:

Now you need to set your drivers properties. You need to change your input variable (by default there is one, if you need to, you can add more). Click on the (X) menu and select "Single Property". A "Prop:" menu should appear, click on it, select material and select the material you want in the input field next to it

Now you need to add the path to the exact property.
To do that, you need to open the info window (it is under "scripting") and then change the value you want to reference. This will show you exactly the path to your property in the info window. You need to copy this path to the path field of your variable. Note, that the variable already knows the path to your material and you should provide only the relative path from there, so don't copy the bpy.data.materials["some_material_name"] part. The path will probably look something like node_tree.nodes["Diffuse BSDF"].inputs[1].default_value (this is a path to the roughness of a diffuse node)

You can then edit the expression to do what you need, in your case that will probably be something like var * 90
Hope this helps.

The First method wouldn't work for two reasons. One Being that since you connected the value node and math node directly to the rotation vector the value will control all the axis but I want to control only y axis well that can be fixed by using combine XYZ node, The Second reason  being the input given in the value node is not in radian i.e. if I enter value as 90 the 90 here is not radian but some different value so I wouldn't be giving input of 90 degree but some other value but by playing around the value node 90deg is 1.556 value.

I don't know about the second method as I don't know phyton

You don't need to know python, all you need is the path, which you can copy from the info window, no coding necessary and to be able to write the relationship using a formula. Combine XYZ node will probably still be necessary. As for the first method, both problems are solvable and the result would look very similar to what the other answer suggests


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Is it dangerous leaving PC Rendering overnight?
Not actually a blender issue, I’m rendering in Cycles using Blender and the animation is quite long, I started rendering 13 hours ago and it’s not even at half animation. So, since it’s a job that I need to deliver soon, I thought that the only way was leaving PC rendering overnight to not even make customer wait even more. I use a 1060 6GB with 3 fans and very gently overclocked, so no temp problems (max 51) but CPU is ridiculously overheated since cooler is the Intel stock one (Intel core i5 9400F, min 79 - max 87) is it dangerous leaving it rendering overnight? I’m afraid room will go on fire or something will melt down...

Most modern CPUs and GPUs will shut down if they get near the overheating temperature. Also, they will usually slow down before reaching that threshold.

It will be the same temperature no matter what time of day you render. Overnight, however, you aren't doing other things on your computer that will heat it up more. The chances of a CPU starting a fire are very, very, very low, so you don't need to worry about that. I have rendered plenty of renders overnight, and it has been fine (not even warmer in the room) in the morning.
However, there are easier ways to accomplish a large render. I recommend checking out Sheep It Render Farm. It is a free render farm for blender users. Just upload your blender file (make sure to pack all external data) to the website and then ~800 people around the globe will assist in rendering, myself included.

Rendering is very much the task that can make a poorly cooled computer overheat, by constantly taxing the CPU and/or the GPU at max capacity for long periods of time will definitely increase the chances of that happening

@Duarte Farrajota Ramos My mistake, I have not experienced overheating in my machine and I have done multi-day renders (48+ hours). Will update answer.


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Find Intersection index faces two mesh
I need to find in the object 1 the index of the polygon that does not intersect with the polygons of object 2.

Needs more detailed description. You have two objects and they are intersecting? Which index (1 to 5) do you want in the picture?

I need to find all the faces of object 1 that intersect with object 2.Sorry for this description, I do not know English well

authors: Влад Киндюшов


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X-Ray like Shading Error in EEVEE but not Cycles
I sculpted this Manta Ray and tried texturing it. I Noticed that when in EEVEE, somehow the base Geometry is clipping trough, as if i had the XRAY switched on. When i use EEVEE, this problem does not appear. Does anyone have an idea what might have gone wrong?

Is the alpha of the principled 1.0, or less than that?

Ten to one, you have the shader blend method set to “Alpha blend,” which is useless for things more than one face thick. Use “alpha hashed” instead.
This is probably in the top 10 FAQ.


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metarig is invisible, can't see it (scale, move pose it)
I'm a super newbie here. Currently using V 2.91
I started with some tutorials and stuff in youtube and it was all going well until I messed up with some configuration in the process of editing my character and now I can't see my Rig anymore. I tried searching for answers online but nothing worked. Everything seems to be fine and working but I can't manage to see the rig.
I'm going to upload the file and take a screenshot:
Blender File: https://drive.google.com/file/d/1klVfvf6Vt__D6HR9IAO5_OmDXZZaXRSh/view?usp=sharing
Thanks in advance.

Are you sure the screenshot is from this file? There is no metarig in the file. Just be aware, that the cloth of your character is way too dense to animate. It has a few million(!) verts. That's the reason why the blend file is almost 80 MB big.

Wow! I didn't notice that! Thanks for the heads up!

A friend of mine got what I did to mess up. Really simple, for anyone that might make the same rookie mistake, on the upper right side there's viewport options and "bones" weren't selected. I just clicked and It was back to normal.


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How do I use world properties in blender?
I am doing a lighthouse project in Blender 2.92, and for the last 3 hours, I've been trying to figure out how to access world properties like Mist, Horizon and Zenith. I can't figure out how to access Blender Cycles as I'm told that's where I can access these properties from.

Hello, where did you see that these properties were available ? For the mist you have to enable the Mist pass in the view layer, then the options will be available in the world properties. But Horizon and Zenith sound like it comes from a sky add-on or texture

Most of these things would be in various tabs in the properties editor on the right hand side of the default UI, but as @Gorgious said, zenith and horizon are not currently in Blender. I checked, and these are from Blender Internal Render, which was discontinued in 2.80 release. I’ve included locations for Blender 2.79b, the last release with the Blender Internal Render engine.

Mist. Visual effect. Makes distant objects more and more transparent to the world background. It seems you are expected to composit this in yourself nowadays, and you can enable it for compositing in Properties editor -> View Layer Properties tab -> Passes panel -> Data sub panel. It will then show up as a Render Layer node output for this layer in the compositor. In Blender 2.79b with Blender Internal Render enabled, you can also enable readymade mist in Properties editor -> World tab -> Mist panel.
Horizon and Zenith. Archaic settings of the Blender Internal render engine, which was no longer used with the 2.80 release. In 2.79b with Blender Internal Render enabled, you can find these settings in Properties editor -> World tab -> World panel. Note that “Zenith color” will be unavailable unless “Blend sky” right above it is checked.
Cycles. A render engine. Comes packed with blender as an add-on and enabled by default, but not selected for use (you bought the screwdriver and it’s in your working tool bag, but it’s not in your hand yet). The render engine that is selected by default is EEVEE, which provides pretty decent fakes of physical accuracy for quick rendering. Cycles provides high-accuracy photorealistic ray-traced renders and hopes for an NVidia GPU to do its high-spec work. You can currently change the selected render engine in Properties editor -> Render Properties. It’s at the top. In Blender 2.79b, you can change the selected render engine in Info editor. In the default 2.79b UI, this is at the top of the window.


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Editing shape after parenting armatures
After parenting the body with bones I tried to modify the shape and add more loop cuts in edit mode but, when I am trying to move the hand in pose mode I got this shape? so, what is the issue?

Your weight paints are probably off. Click on your model, switch to weight paint mode, go to Object data properties panel, and click on the bone causing the problem under vertex groups. Where the problem is occurring, there should be red dots. Change the brush type to subtract and make the color of the red spots causing the problem blue.
Here is where you click on your bone:

Click on the option that has the name of the bone causing the problem.
If you want me to elaborate, just ask.

I can’t find the bone in weight paint mode. It disappears.

Sorry, I didnt clarify something, I edited my post


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What is the command for calling the Mesh menu (accessible in Edit mode)?
I would like to create a keyboard shortcut to call the Mesh menu, similarly to the way that Vertex, Edge, and Face menus are bound to hotkeys. However, when I right-click the Mesh menu button, I am given no option to create a shortcut. The only option available is "Add to Quick Favorites."
By searching keymap entries, I've found that VIEW3D_MT_edit_mesh_faces calls the face menu, VIEW3D_MT_edit_mesh_edges calls the edge menu, and VIEW3D_MT_edit_mesh_vertices calls the vertex menu; I expect there to be a variation of this command for the mesh menu, but I don't know that it is, and my guesses haven't borne out.
VIEW3D_MT_edit_mesh_mesh does nothing; neither does VIEW3D_MT_edit_mesh_meshes.

The entry you are searching for is VIEW3D_MT_edit_mesh. You need to add a new entry or overwrite some entry you don't use:

In the future, if you want to find the Python name for some menu you just need to activate "Python tooltips" under Preferences > Interface. With this option activated, the tooltip will appear when you put your mouse over every menu.

That's perfect. Thank you!


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Why do i have bald spots with hair particlesystem?
I have a camel mesh, both mirror and subdivision surface modifier applied, with armature on it and I wanted to give it some hair. I added a hair particle system with interpolated children and made a density group, but I have got some bald spots in some areas. I am sure, that I am using correct vertex group to control density, I tried to make some changes in the emission panel in the advanced particle settings. The only way to solve this I found was to make same number of hairs per face, as is the number of faces, but since I have over 12 000 of faces, this isn't quite ideal. here is picture of how it looks:
here are the problematic parts of my model:  (so far I know about tail and legs. It isn't whole model, just the parts.)

I think we need more info. The easy way is to share the .blend file. If you are not OK with sharing your model give us only the back legs -in case that the error is still there wen you cut them out.

where can I share my model?

here

I was about to suggest PasteAll, I didn't know about a site made for uploading blend files for Blender Stack Exchange. Cool!

OK, here is the file

applied particle after disabling subdivision surface modifier and then turned it on worked for me.

For some reason that I cannot find, some of the interpolated child hair strands are growing inwards -no bald areas actually. You can see little dots in those areas which are the root of that bad children that are growing inside the mesh. The interpolation is bad though the face normals are fine and I couldn't find any other cause for this.
So, as the problem is the interpolation between parents, the solution is adding more parents manually.
Go to the Particle Edit mode, then choose the Add tool and add a parent wherever there is a bald spot. Then, the Children will rearrange around the new parent and will face towards the face normal as the parent.

You can se above that I fixed the right leg.
Note that doing this means have more parents and, eventually, will create more children too. You might want to change the number of children.

I was searching for this answer, but it does not seem clear what the answer means by "use the Add tool and add a parent wherever there is a bald spot". What is the Add tool? Does this mean to create a particle system for each bald face? (Strangely, I too am creating a camel!)

When you are in Particle Edit mode, you'll see a bunch of tools in the viewport's Tool shelf (T in the Viewport). The usual one is the Comb tool, but you'll find some more including the Add tool.

I've been struggling with this for a while now and I think I found a solution to these problem bald spots. Using the puff tool lifts hair particles that are trapped under the mesh--especially after combing. Using the add tool does help as well but you can get away with less parents by puffing out the particles first. Hopefully this helps. Happy Blending!

I should comment on the image as well. The hair on the ear on the right has been puffed the ear hair on the left hasn't been puffed. I have also discovered that the smooth tool has a similar effect almost more effective. Try them both as a solution.

Also, n-gons can sometimes provide hair issues like this. So if there are some problematic areas with fur, check the topology first.
Fr example:

I recently encountered a similar problem myself. The particle distribution wasn't remotely even on my model and showed up all patchy. I also had problems with the particles changing 'on their own' when I switched from particle edit mode to object mode. On my travels I found this question, and the last answer pointed out that having modifiers on the model with different values for "view" and "render" can cause all kinds of issues with particle fur. I found setting my modifiers to show the same value in render and viewport instantly solved the problems I had with patchiness and with particle edit. I also found when experimenting with the mesh that sometimes just adding extra edge loops (particularly on the legs of the model, where the faces are frequently longer than the rest of the body) can help the particle system have an easier time distributing the hair evenly.

I tried to remove all modifiers, add extra edgeloops and also set the view and render values of everything i could find to the same value, but it didn't work.

I had the same issue. In my case, I fixed it by ensuring these thing in this order:

Scale and rotation was applied on the mesh object
Transforms were applied
Normals were correct (Ctrl+N in Edit Mode with everything selected).

Then, if there was any bald spot, using the Particle Edit mode, I could "paint" more hair over the bald areas without problem.


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Weird lighting problems in video?
There might be an answer somewhere else but I can't find it.
You can't add videos here so here's a picture of the lighting problem:

It's fine at the beginning of the video but then it starts flashing and has the line down the plane.
My lighting is sun lamp and an environment texture.

Does anyone have a solution to this problem?

Is you ground mesh duplicated? Sounds like Z-Fighting

@NoviceInDisguise no it's not :/

Worked it out. I subdivided the plane and put the sun on multiple importance. I don't know which fixed it but I'm not having the problem any more

That's odd.. If you still want an explanation, is it possible you could upload your .blend?

@gandalf3 to upload the .blend do I need to link a Dropbox or blend swap or can you do it within the website?

@Chickenator Including a .blend file

Added a .blend if anyone wants to try work out what was wrong

Hm.. It doesn't appear to be happening for me in the .blend you uploaded, even after unsubdividing the plane and disabling MIS.

@gandalf3 did you only render the first frame or did you do the others?

I looked through most of the frames in viewport render and rendered the last frame, but no artifacts..

@gandalf3 maybe it had something to do with some compositing. Try adding a despeckle with 0 on both sliders and then add a soften with 1 fac and see if it still shows up. I can't check right now because I'm rendering

@Chickenator That had no effect.. Oh well, If it's not happening, then I guess alls well that ends well..


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Smoke only emits for 1 frame?
The smoke emits for one frame and then all the smoke freezes. My scene consists of just a domain, a gun barrel which also has smoke collision and smoke flow inside the barrel.
Here's the .blend:

Any ideas to why this is happening? Is it a bug?
Thanks

working fine on 2.73 but not on 2.74

@Chebhou does that mean its a bug created in 2.74?

could be, or some changes in the simulation system


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Why are the renderlayers rendering black?
I understand there are a lot of questions similar to this but non of the solutions worked for me. I have a camera, I have lighting, rendering other things worked for me, I've restarted, etc.
Here's the rendered view for one of the renderlayers:

Here's the rendered view for the other one:

But when I render:

Black for both of the renders.
.blend:

Is it possible you could upload your .blend?

@gandalf3 edited to add .blend

This is because the Scene layers corresponding to your renderlayers are not enabled:

If you enable the right scene layers (or all of them), then it works as expected.
Note that by default the 3D view layers are linked to the scene layers. You may want to turn this off by toggling Lock Camera and Layers in 3D view > Header:

Also note that there is nothing on the Lines renderlayer; perhaps you meant to select this layer instead?

Great thanks! I'm new to using render layers so I thought I made a stupid mistake. Thanks for the quick answer


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How to make a wave that follows empty?
So I'm trying to make it so that when the empty goes across the object it creates a wave. I'm following up this question. Here's the .blend

As you can see if you drag the empty slowly across the object it creates a single wave but if you play the animation it just makes multiple waves. I'm trying to re-create the effect you get from dragging the empty across the object. How would you do this?
Thanks!


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How to create a slope
Hey so i want to do a straight slope between the cubes, as shown by the black drawing. Any easy way of doing it? My solution of creating another cube cute it in half and try to get it to fit but that cant be the easiest way?
Thanks :)

Welcome to Blender.SE! Please give us further information. Are those cubes separate meshes or one mesh? You can also upload your .blend to http://blend-exchange.giantcowfilms.com/, then click 'edit' beneath your question, paste the code given to you there and click 'Save Edits'.

Its a few meshes, i have points in every corner if that helps.

Tab into edit mode
Select and delete these interior faces

Select these verts and hit f to make them a face

Select these verts and hit f to make them a face

Select these verts and hit f to make them a face


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How to set up Blender for Multicore Animation
I use Blender as a video editor.
After setting up the video I want to process including correct Start and End frames I click "Properties->Render->Animation".
My CPU usage climbs to a range from 20% to 25%. I am running an i7-3770K @ 3.50 GHz with 32 GB Ram. Blender is working on a physical drive, not an ssd. The i7 has 4 cores. With hyper threading that is 8 Hyper threads. I think Blender is running animation on only one core.
When I try to research this topic I get a mixed message.
I can find performance analysis multi core vs single core. I can find a Microsoft demo how the job queue can be executed parallel on a cloud service.
I can find entries that say the Renderer is multi core the rest is not.
But I can not find the settings to enable my animation to be multi core. I assume this is possible since it looks like it is part of the Renderer .
Is there something definitive like an official source on this?
How do I set up my Renderer so that It utilizes all (or most) of my machine?

When you say "After setting up the video I want to process" does this mean you are using blender's video editor (VSE) or are you rendering a 3D scene?

@RayMairlot Setting up the video means that I drag and drop an avi file onto the Video sequence editor. When that is done I change the endframe to fit the video. Other settings were stored in my preferences. Not sure if that is the VSE Editor or not but it is not a 3D Scene.

VSE = Video Sequence Editor.

Related: http://blender.stackexchange.com/questions/7738/how-to-make-vse-render-faster

It seems like the current VSE targets in the road map do not include multithreading. That may change in the future.
The underlying issue of slow rendering is solved in this thread.


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AlphaMasked images turning pink in Cycles
I still cant seem to get this to work, I have the Image I need of a leaf and am trying to make it transparent. After all of this is set up using a mix shader and transparent shader the image is clearly found by Blender. In the Material view-port you can see the image on the plane, However in Rendered view it comes up with the missing pink colour. Please try and just chuck ideas out of how to help. Any ideas will be tested. Thanks Guys

Are these smartphone photos? How about some actual screenshots where we can actually see what's going on in the shader panel?

Please make screenshots with Ctrl+F3 while in Blender window or press Printscreen button (if available) to make a screenshot, save it in image editing program and upload here. Also if you want to post 2 screenshots in 1 image do not rescale them, this makes them less possible to undertsand, thanks. Pink means that image isn't found so please pack all images in your file and upload it here

Possible duplicate of Texture appears pink in Blender Render

But this is in Cycles.? @Leander

Doesn't matter, probably the texture nodes image is not found anymore. I see you have marked icYous answer as accepted, so I guess you figured it out. @Sarsha.

Usually when an object turns pink it is because the original file got moved since you last opened Blender.
It is still showing up in your 3D window because that is using a different part of ram.
I would relocate the file and load it again and make sure "leaf" (leave lol) it where it is once you bring it in to Blender.

I  will test it and reply on what the outcome was. Many Thanks


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Weight Paint Normalize Moves Mesh
I have a problem with a mesh that moves unexpectedly with a bone, so I thought that I might want to normalize all the bone weights to get a "true" picture of the weights. Normalizing however, moves the mesh around which I didn't expect. (some of the bones are posed when I do normalize).
My impression was that the overall bone-influence result would be the same after normalizing, but since the mesh moves around, it seems this isn't so. Am I doing something wrong, or did I just mis-understand the normalize-all operation? (I tried both with and without any bones selected).
(also, noob-alert)
EDIT: Ok, I may have totally misunderstood something. But I tried making a simple skeleton and object: Two bones controlling a cube'ish thing. Painted all vertices red for both bones (weight 1.0 for both bones), and then picked normalize all. Now one bone had weight 1.0 on a vertex, the other bone got 0.0. I understand that blender has now made sure total weight <=1, but I would have expected the weight to have been shared, something like 0.5 for each bone on that vertex.

Thanks to "stilltrying" from blenderartists.org, I found my answer.
The little Normalize All option called "Lock Active" is on pr default, meaning the active vertex group was unchanged. This of course leads to the relative weights being changed, thus causing the mesh to move due to the Normalize All operation.


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An Issue while applying texture to all the ivy generated curves
So I am currently following a tutorial by tutor4u, on ivy gen . https://www.youtube.com/watch?v=LshPEGiHsqc
So the problem I have is that, there is the stage in the video where he selected one ivy curve which had textures applied to, and then he went to select=select all by type=curve and then he did crtl+L=materials and that texture got applied to all the curves . But when i did it , it got applied only to the ones on the floor/plane mesh . Is this a bug or something ?
sorry but a beginner here
You can see my issue in the image below :

Share your file. https://blend-exchange.com

It's impossible to know what is at work without more information, but I wanted to offer some general information anyway.
It's important to understand what is happening when Blender selects objects. The first object to be selected isn't merely selected, but is also active. An active object is a special case of selected object, and there can only ever be one active object at a time, even if multiple objects are selected. When adding multiple objects to any selection one at a time, the last one selected is always the active object. When you use the Make Links menu, as you did above, Blender needs to know what object is going to be the source object for the data transfer. The active object is always the one from which data is transferred, and all other selected objects are the ones to which that same data is transferred.
Now, Blender also remembers the last object to have been selected, even if no objects are selected currently. This is important, because there are ways to select multiple objects without selecting them one at a time. If it were the case that only the last object selected is ever the active object, then which object would get designated as active when all objects are selected at once? The answer is, the one that Blender remembers being exclusively selected previously. And it turns out that every object is designated as exclusively selected (and therefore active) as soon as it is initially created. Meaning that there will always be an object in the scene that Blender remembers to have been exclusively selected previously. So there will never be a condition for which selection outcomes prevent Blender from knowing which object to designate as active.
It's also important to understand that objects which are currently invisible, or which are marked as unselectable currently in the Outliner, will not be added to any selection made via the All By Type menu. This rule also applies to the active object. If the active object is invisible or unselectable, it cannot be sourced in a linking operation. Performing the link with the active object cut off in this way will result in no linking being performed. Invisible or unselectable objects will, as a rule, not be involved in any operations which require selections in order to function. So check to see if you have any visibility or selectability issues.
I noticed in your screenshot that you don't have your selectability column exposed in the Outliner. So you aren't yet even in a position to see what the selectability status is for the objects in your scene. Float your cursor to the top-right of the Outliner, above your listed objects, and you will see the icon for the Restriction Toggle. The selectability toggle option will be found under there.
Until you give more info, there won't be much more anyone can say about your file.


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Material Preview is not displaying correctly!
I downloaded a Material via Bridge to Blender. Assigned it to a Mesh.
But unfortunately, it is not displaying correctly. It is kinda grayed out?!

Can someone help out?
Best regards
Til

Add a stronger light in the scene

Hello :). Rendered view is using your flat grey world environment by default. All colors look a bit dull without good lighting or HDRI.


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How to create a growing bacterial colony?
So, I've been trying to create a short 3D animation of a bacteria dividing|splitting itself multiple times like this

I adjusted some shape keys for it, but I think it would be too overwhelming to adjust it over and over...
https://gyazo.com/943601d25fe2386b553a701dd7b3b098
I've also tried using the particle system with the molecular script but I still didn't achieve what I expected to, it's sort of making a particle splits into 2, then they split into 4, and it goes on, any possible way to recreate this? A reply would be great!

I recommend metaballs, but beyond that I’m not sure.

I gave this a try since I think it is a challenging exercise and this is the result:

I made a base capsule object of 2m long with a shape key that turns it in two parts as the gif you provided, measuring 4m long.
When the shape key reaches 1.0, I hide that object and show another 2 capsules to replace it and start animating their shape key. This could be chained several times and create copies of that group of objects to achieve the desired effect.
I also added a curve modifier to them to make it more organic (even the curve can be animated to improve the cell movement).


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Removing shadows from an object, not the shadow being casted
I've got a model that looks best when rendered through the Workbench render engine, but for a specific scene I would like it to still be able to cast shadows. Is there a certain way for the model to cast a shadow without the light affecting them, keeping it in a Workbench-esque render?

You could use the header menu > View > Viewport Render Animation function. Or use an Emission shader rather than Diffuse?


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Other vertices affected when moving one vertex
I have a mesh that I have not created myself. I took an existing mesh and started modifying it for my own purposes. Suddenly I notice some vertices go crazy when I move (or grab) certain vertices.
This is NOT due to proportional editing as far as I can tell (hopefully you can tell as well from the gif).
I don't know how I got these vertices into that state, I have been removing edges, filling gaps with new faces etc on the mesh, and now this. Any idea how I can repair that state? From the image it appears to happen when vertex is moved, but it happens as soon as G is pressed if I do that instead.

Here's an image of some of the settings. You can see x-mirror and topology mirror is on. It seems it's the topology mirror that causes it, removing it stops the weird behaviour. And I don't need it and it doesn't make sense for this mesh, so my problem is solved for me. Maybe others have the same problem.

Are there any modifiers? specifically the Mirror modifier.

No. But I was going to add it later on. I did have x-symmetry on however which I checked because of your comment, and turning it off removes the problem. Not sure I understand why, but I can live without x-symmetry, so it does kinda solve it.

can you add a screenshot of the settings and have you applied rotation/scaling and transform to the mesh CTRL+a ?

Which settings would you like a screenshot of?

the symmetry settings, can you confirm you did do CTRL+a on the mesh?


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UV Unwrap brick wall, gable ends, slanted roof
I am trying to model the inside of a room (brick walls, wooden floor).
I modelled it from 4 planes, put together like walls. This has problems with the edges not aligning when using displacement however. So I think it may be better to switch to a cube.
I find it difficult to uv-unwrap it however.
I want the roof to be slanted. But I can't figure out how to apply the texture correctly if I do, since it becomes warped, like this:

And I wanted a look something like this:
http://4.bp.blogspot.com/-3lENfxSJ_D0/UWWrONi20CI/AAAAAAAABrU/If-dkD5htwM/s1600/IMG_9933.JPG
How would one go around UV-unwrapping for that?
Best way that doesn't warp the "gables" (ends of the house, hope it's the right word) is to unwrap those by themselves. Only disadvantage to this is that blender will not see to it that proportions are kept then, so bricks will not be same size on all sides.
Also if possible I would like to avoid seams at the corners.

Unfortunately I don't have time now to answer in detail but what you need to do is : Is UV unwrap each wall using the project from view method. Front, back, left side and right side walls and importantly don't zoom in or out while changing view before unwrapping each wall. Then in the UV editor select all 4 walls and scale them together.

You need a kind of mix between these to posts : https://blender.stackexchange.com/questions/81551/how-to-unwrap-model-so-its-perfectly-proportioned/81569#81569  and  https://blender.stackexchange.com/questions/156640/how-can-i-apply-exact-texture-measure-cm-in-uv-mapping/156964#156964. But its not nearly as complicated as it looks.  :)

As @3fingeredfrog pointed out, use Project from view.
This will guarantee uniform scale of your texture.

Go to front orthographic view
Select faces and use UV > Project From View
Switch to left/right orthographic view, and repeat.

To keep the UV maps in proportion, scale them all at once.

Thanks jachym and @3fingeredfrog. I never considered the project from view, that I now see people may be using for this. Project method makes me have to line up the pieces to avoid seams at the corners, while just "unwrap" with a single seam at one corner (and then only unwrapping walls) does it auto for me. Both are ok workaround, I can't think of a way to get rid of the last seam. Probably not possible at all.

"I can't think of a way to get rid of the last seam."
Using a seamless texture : With the Walls UV island (single vertical seam) left-hand corner snapped to X=0 Y=0 in the UV space and the right-hand lower corner perfectly aligned to X=1, then scale from X=0 Y=0 by a whole number the "last seam" will be seamless.
I try to explain with screenshots :
Mark seams around lower edges of the walls to separate them from the floor and add one vertical seam.
Then UV unwrap with a margin of 0.0  . The resulting UV island will be perfectly aligned to opposite borders of the UV space.

If necessary rotate the UV island 90° so that the lower edge of the wall is parallel with the lower edge of the UV space.
Open the UV menu and check Constrain to Bounds.
Next drag the island down (or up) in the UV space until the bottom edge of the island is aligned to the lower edge of the UV space. Having Constrains to Bounds enabled will keep the island within the UV space and the island will seem to "snap" to this lower edge and left-hand corner.
Now you can uncheck Constrain to Bounds.

In the UV editor, change the Pivet to 2D Cursor.
Check that the 2D Cursor is at X=0.0 Y=0.0 of the UV space.
Select the UV island and scale by a whole number. This will result in the UV islands right-hand edge exactly lining up to the X = 1.0 of the repeating UV space. (X=1.0 is also X=0.0 of the following UV space.) So will be seamless.
(Just a note here: If you notice that the UV island has been reversed along the X axis in the following screenshot it is because I started out unwrapping the inner surfaces of the walls but switched to outer surfaces to show the seam better.)

And finally the result of using the 2D cursor as pivet for scaling by a factor of 6:


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When Blender crashes during rendering
After asking a good number of questions,
I felt it best that I come with some tips that I have discovered and learnt on my own.
One of the things I've heard is that there are people that have tried to render a video
and that Blender (or CUDA, GPU rendering) would crash and their video file would be corrupt.
This usually happens in Cycles. How does one avoid this?

Hello Edward thanks for the thorough answer. It is fully encouraged to answer your own question and post your findings on a certain matter for everyone's benefit. However to do so please use the answers section bellow this post, do not answer in the question post itself.

@DuarteFarrajotaRamos Thanks. I did see the link on "answer your own question" but it didn't explain or give examples on how to formulate the "question" in the question post before the "main article" in the answer section.

No problem. You can still edit your question and remove all the text pertaining to the answer and paste it below in an answer post. Probably elaborating a bit on your first paragraph to read more like a question is enough

After asking a good number of questions,
I felt it best that I come with some tips that I have discovered and learnt on my own.
One of the things I've heard is that there are people that have tried to render a video
and that Blender (or CUDA, GPU rendering) would crash and their video file would be corrupt.
This usually happens in Cycles.
How to avoid this?
What I'm about to tell you is no miracle worker.
There is still a chance it dies depending on how complicated your scene is
and how much memory your computer or video card has.
To begin with, set all your rendering options according to what you want.
Make a few still image renders here and there to make sure you are satisfied with the quality.
In Output set where you want the result to be saved to and give it a name and a period (.) but without setting an extension (png),
check File Extensions, but uncheck Overwrite, Placeholder and Cache Result.
Set the format to PNG, and Compression to 100%.
Yes, we are writing image sequences here. Even the most professional Blender Gurus
with the most powerful of computers do this. This is to ensure that no matter what happens,
be it that the OS decides it has had enough or power failure/outage,
what you have rendered so far is safe and sound and you can pick it up right where you left off.
Another option you can check in Performance to save on RAM is to check Save Buffers.
Now that all that is setup, Close Blender!
To ensure that there is enough memory to render our video
we do not want Blender's GUI to be using any of it, and if possible, not even the Desktop.
What we are going to do now is write a little script file that is going to render our video.
Linux Bash Script
#!/bin/bash
cd "/path/to/blender/"
for i in {1..250}
do
   foo=$(printf "%04d" $i)
   if [ ! -f "/absolute/path/to/project/imgseq/video.$foo.png" ]
   then
      ./blender -b "/absolute/path/to/project/project.blend" -f $i
   fi
done

Lets go through this step by step.

The first line #!/bin/bash is pretty much the header telling Linux this is a bash script
and should be interpreted as such.
Next we Change Directory to wherever you have Blender installed cd "/path/to/blender/".
Now we create a for loop in which we iterate over the number of frames your animation has,
in which i holds a number from 1 to 250. Don't forget the do right after that.
The command foo=$(printf "%04d" $i) creates a formatted string where the number i gets 4 leading zeros. Remember that Blender will name the file with 4 leading zeros.
Next we test if a file with your video name that you set in File Output plus the frame number and png does not exists.
The ! in front of the -f is a negation so one would read it as 'if not a-file "video.number.png", then...'
This will ensure that Blender will not be launched to render this frame if the frame already exists.
So if this frame has not been rendered, launch blender (./blender) in the background (-b) and render the blend file
("/absolute/path/to/project/project.blend") on frame i only (-f $i).
Finally, end the if block with fi and our for loop with done.

Save this file somewhere, maybe with your blend file, and call it something simple like render.sh.
Make sure it is executable by doing sudo chmod 755 render.sh.
When you are ready to leave your computer running for hours on end, open a terminal or drop to a tty
(Ctrl+Alt+F1 - F6),
navigate to this render.sh and run it (./render.sh).
How to stop it?
If you want to interrupt your rendering at that moment, hold Ctrl+C
until Blender isn't trying to restart itself anymore.
If you want Blender to finish off its current frame, open a new terminal or jump to a different tty,
type in ps -A |grep render.sh or whatever name you gave your script, make note of its number
and type in kill number, and wait until Blender is finished.
Windows Batch Script
echo off
C:
cd "C:\path\to\blender"
for /L %%i in (1,1,250) do (
  set 'foo=0000%%i'
  set 'foo=!foo:~-4!'
  if not exist 'C:\absolute\path\to\project\imgseq\video.!foo!.png' (
    blender.exe -b "C:\absolute\path\to\project\project.blend" -f %%i
  )
)

Pretty much the same principle as the shell script, but lets go through it anyways.

The first part is optional. This will ensure that the whole script is not printed on screen each time a frame is to be rendered.
After that, C: ensures that we are in the drive that Blender was installed to.
Next we change directory to wherever you have Blender installed with cd "C:\path\to\blender".
Now we create a for loop in which we iterate over the number of frames your animation has,
where /L tells for that we are looping through numbers, %%i shall hold these numbers,
within the range of (start, step, end). Don't forget do ( at the end of this.
We then set our zero padding to %%i using the two lines set 'foo=0000%%i' and set 'foo=!foo:~-4!'.
The first adds the zeros and the second makes sure there are only 4 digits in total. Remember that Blender will name the files with 4 leading zeros.
Next we test if a file with your video name that you set in File Output plus the frame number and png does not exists.
Notice the ! surrounding the foo which is our zero padded %%i.
Unlike the shell, batch uses not instead of ! to negate what we are testing for.
This will ensure that Blender will not be launched to render this frame if the frame already exists.
So if this frame has not been rendered, launch blender.exe in the background (-b) and render the blend file
("C:\absolute\path\to\project\project.blend") on frame i only (-f %%i).
Finally we end the if and for blocks with a ) each.

Save this file somewhere, maybe with your blend file, and call it something simple like render.bat.
If you want the console window to stay open, press the Window Key, type in cmd and enter,
navigate to where this render.bat file is and simply run it by typing in render.bat.
If you don't mind it closing when it's done, simply double-click render.bat.
How to stop it?
Pressing Ctrl+C, Y and Enter will stop the loop, but Blender will continue on its current frame.
To stop Blender itself one would go into Task Manager, find blender among the Processes and End Process.
To stop it all, simply close the terminal (x).
Mac OS
As far as I can tell, Mac uses the same bash script as Linux, but if I'm wrong do let me know.
Additional Thoughts
Some of you may be noticing that this method will close and re-open Blender for each frame rendered,
and you are probably wondering "Won't this put a strain on the computer?"
Not necessarily. I have noticed that if I were to run Blender in the background and include -a
to render the whole animation in one sitting, it won't clear the memory properly between frames
and one would run into memory problems.
By closing Blender after each frame it will clear all of the memory (if not 99%)
and leave plenty for Blender to take care of the next frame.
The only factor that may interfere with this is how well your OS manages memory.
"What if I just give my project to a Render Farm like Sheep-It?"
That is a possibility if you need to use your computer for other things in the mean time,
but there are a few factors to consider which would make this difficult.

In the case of Sheep-It you can only upload 500mb, so if your project has a lot of textures or cached dynamics
that exceed this limit, even compressed, this will not work.
If your project takes a long time to render you'll run out of points,
and based on that system your project will get less attention, and thereby take longer to complete.
You are part of a studio of some kind and doing this may violate any agreements you have with your boss.
You yourself want to keep this project a big secret and you do not want the slightest bit of exposure until it is done.
Your project contains questionable material that may violate the Render Farm's terms.
You want to render your project in a special or non-linear way.

Render Farms like Sheep-It pretty much does the same thing as the scripts above.
Get the project, check what frame hasn't been rendered, then tell Blender to render that one frame in the background, then close.
Although because there is a little shuffling involved, projects will be downloaded and deleted several times
as well as Blender being re-opened and closed.
"My Blender project contains audio. Can I render that in the background?"
As far as I can tell, you cannot. That would've been a handy command to add at the end.
Sadly, you'll have to open Blender and click the Audio button in the Render panel and wait.
So, now that your rendering is complete and you have a long list of PNG files,
you'd like to turn them into a complete video. There are a number of ways to do this.
The first and foremost way would be to put them into your video editing software
so that you can apply any extra visual effects or sounds that are needed.
If you want an mp4 as soon as it is all complete, you could add the following to the end of your script:
ffmpeg -r 24 -start_number 1 -i "/absolute/path/to/project/imgseq/video.%%04d.png" -f mp4 -crf 15 "/absolute/path/to/project/imgseq/video.mp4"

This will of course work if ffmpeg is installed and recognized as an internal command.
If not you'll have to Change Directory to where ffmpeg.exe is hiding just before this command.
The first part of this command -r 24 sets the frame rate. Be sure it is the same one you set in Blender.
The next part -start_number 1 tells ffmpeg that the image sequence starts at 1. If your video actually starts at frame 0, you can skip this part.
The -crf you can change to 0 if you want 100% lossless compression, but that would be a huge video.
For any other video format, feel free to look them up on your own.
Hope this helps you in rendering your massive projects.
If the CUDA still gives up half-way through a single frame then the only thing I can think of is that
there isn't enough VRAM or there is a Shader that your GFX card does not like.
You can experiment and see if CPU rendering works any better, even if it is slower.
/Edward
(blender 2.79)
EDIT It has come to my attention that sometimes the console in Linux (tty) can be a bit slow if it halts execution as it refreshes the screen for a new line. This can be a problem if your project has a lot of objects and textures, and printing out each line takes far too long. One way to speed things up is to add  | grep Remaining to the end of the ./blender line or after typing ./render.sh.


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Frame-Duplicated Metaballs not rendering in Blender 2.79
I am trying to create a flow of water by duplicating metaballs along a curve. I've gone through the motions of creating a curve and a metaball, setting the Parent of the metaball to the curve, set the Duplication to Frames, unchecking Speed, and animated the End frame. Looks good in the viewport (sometimes needing to click the Update buttons to get it to update).
However, when I go into Rendered view or actually rendering the thing, none of the metaballs show up, not even the starting metaball. Changing Duplication to None shows the whole thing in Rendered View, but when I do anything to update the metaballs I only get the starting metaball. I even played around with the metaball's resolutions to no effect.
Is there any other method to create this growing "sausage"? Remember the material is semi-transparent so using ordinary spheres will produce ugly overlaps.

Simple plane with array modifier along curve and dupliface option can be used instead of your current setup. As for sphere overlaps - this can be eliminated inside shader, forcing all transparent bounces greater than 1 to be fully transparent (downside of this method is having a big number for transparency max bounds to reduce black artifacts).

@SergeL I'm not getting the desired result, or I'm just misinterpreting that first part. Maybe make a full answer (tutorial) what you mean?

I don't know whether it's a bug or not, but if you ALT+D duplicate metaball on the same layer, dupliframed metaballs start rendering fine. To hide this copied metaball, clear relation to parent object (ALT+P) and put it outside view area or parent to camera and move behind it.

Very odd. Your blend file seems to work, but when I try the steps you suggested, it did not work.

Maybe share your file?


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How can I get the new Templates to work in Blender 2.79?
The Blender manual states in this article that 2.79 introduces a new Template System. This empowers the user to dynamically change aspects of Blender, like the startup splash screen, keyboard layouts, certain scripts, etc. The beauty of this is that users can create their own application on top of Blender when exploiting this.
I was following the manual as best as I could, but my templates never actually show up. This is the content of the folder I'm currently using:

The folder location is set via environment variables BLENDER_USER_CONFIG and BLENDER_USER_SCRIPTS. So they are not at their Default, but this has always been working nicely for me.
I would now expect to either be able to switch to that template either using the Splash Screen or the File Menu. But my custom template isn't listed anywhere. What am I missing? Even if I manually generate a ZIP file and use Install Template from File, Blender puts the files in that location just fine, but never actually shows or loads the template.

It looks like it doesn't work with Environment Variables at this moment because of this bug:
https://developer.blender.org/T52442
I hoped it should be solved by this fix:
https://developer.blender.org/rB2aa2bec43a7f1fa214833c73d033ae1785c600f3
... but it still does not work even in the most recent builds.
But regardless of Environment Variables, you should still be able to test your template by moving the bl_app_templates_user folder with your template to Blender's user directory c:\Users\yourusername\AppData\Roaming\Blender Foundation\Blender\2.79\scripts\startup
So it will look like this

Make sure you no longer have a duplicate of your theme in the previous path (Blender program directory).

On another note, can we edit the splash now? Last I remember it was locked

Yes, if you put splash.png to the template folder, it will replace the original one - I have already tested it.

@JanKadeřábek I've added a comment to the bug report as well, maybe that increases the attention to this. Copying the files locally works, though that eliminates the advantages of a portable installation alltogether.

I noticed your comment there, thanks. I think it is just an early implementation of this feature so I am sure / hope we will get lots of changes & fixes soon.


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How can I force the Compositor to update via Python?
While working on an Add-on that does node connection stuff, I came across a problem I can not find a solution to anywhere: The compositor nodes are only ever updated / evaluated, as long as there is a compositor space open somewhere. If you for instance have the image editor maximized, compositor node tree changes are not evaluated at all.
I am displaying the result of my Python node reconnections through the Viewer Node in the image editor. As long as somewhere there is a Compositor window open, this works. As soon as you switch that window to something else (like a 3D View), updates are not calculated at all.
here is a .blend file to test this, the GIF below shows how to trigger the behavior I described:

I have tried calling the update, update_tag and evaluated_get methods pretty much anywhere I can think of. Is there a way still to force a refresh?

Compositing output can be updated by rendering without any Render Layers nodes in the compositing node tree.
See documentation about Render Operators
bpy.ops.render.render(animation=False, write_still=False, use_viewport=False, layer="", scene="")

If I am not mistaken this use_viewport parameter seems to be for controlling if the render process is shown in the UI. It is false by default so it should not show the render in the UI unless specified otherwise.

unfortunately this won't trigger the update either.

Could you share some bit of code to reproduce the issue?

Did you mean you need to recalculate the compositing output? That happens if you render and do not have any Render Layer nodes.

I'll update my question with a blend file, script included. In the meantime I'll test your idea with triggering rendering, this might work for such a case, has a lot of side effects though

rendering does indeed trigger such an output update. however, it does a lot more, like opening a render output window, switching to Render Result, etc. I wonder if there is some operator other than that that could be called to trigger these updates?

I misunderstood what you were asking previously. If you need to recalculate the compositing result I think rendering is actually intended functionality here.  I use this script from time to time and it works without trouble on 2.79: https://github.com/Martynas-Ziemys/Blender-Scripts/blob/master/CombineSplitCameraRender.py simple  bpy.ops.render.render(write_still=True) seems to work without showing the render in the UI in that case.

nice, this works!