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Modifying one end of a spiral/curve
I have created a spiral using the "Add curve" function and want to taper just one end of it (kind of like extruding and narrowing). Is there a way to do this? If not, what would be the best way create a spiral that enables the modification of its ends. Thanks.

You may do it using a curve as a Taper Object's target to change the thickness along the spiral's axis. You can then change its width using the curve's specials menu.

After creating a curve add a Bezier Circle and set it as a target in the Bevel Object window (Curve Data header).

Add a Bezier Curve and edit it in Edit Mode so it's straight and placed vertical.

Select the spiral in Object Mode and set the newly added Bezier Curve as a Taper Object target.

Modify the newly added curve to change the thickness along the spiral's axis. Experiment with it for different results.

Finally select the spiral in Object Mode, press W-->Width Size and drag the cursor away to change its width.

Every curve point has a radius value that will adjust the bevel radius and can be found in the properties region.

You can use ⎇ AltS to adjust the radius value and combined with proportional editing you can get a gradual falloff from the active point.


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How to create a drilling simulation?
I want to show a dental turbine drilling into a tooth . I can't  create the effect of the surface being ripped up by the turbine. I want to animate the shavings of the surface, to give it a realistic appearance .
I've created all what i need ( teeth bones turbine and instruments...)  I can do the basic animation, but I can't figure out how to have the section of the tooth be removed after drilling .
This is an exemple for what i want  to create : https://www.youtube.com/watch?v=DmiMQDZFSQY&index=52&list=WL

i am new on blender . and i am looking to create educational videos of dental medicine and i have difficulties in the simulation of the drilling

What problem do you have exactly? What you've done so far?

Do you mean something like this?: https://youtu.be/NAXGQNwRUfk?t=17

@cegaton LOL :D

@PaulGonet yes exactely (y)

@cegaton you make fun of me or what ??? . my english is not very good . i thought that you are an educated person . i didn't think you are too arrogant

I think using shape keys and particles may do the job.

source: Stack Exchange

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

sort: votes


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How can I model a tap shape?
I am facing an issue modeling this shape. Any clue?

This is as far as I could get:

Maybe this can help http://topologyguides.com

Select the top of the base you have made and extrude up. Select the side of the new extrusion and extrude it outwards.

@sambler: Not quite what I am looking for, but thanks.

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

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

Mashaa Allah Tabarak Allah, this is awesome.

Try extruding the top, rotating, and extruding again to make the handle then alter it in sculpt mode.

I am trying to find an easiest way. Sculpting is a tool I want to avoid on this model. But I will give it a try. Thanks though.

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


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Problem with rigging (the eyes and eyelashes don't follow the head)
I'm making an anime model. When I go to Pose Mode and try to rotate the head the eyes don't follow it well. The eyelashes change position and the eyes pop out of where they should be. I have painted the whole head red in the weight paint mode. Should I paint the eyes in a different way?

I'm voting to close this question as off-topic because it is not written in English language as per site rules

For what is worth you should also probably post your weight paint screenshot as well as an image showing the issue.

The only words I could understand here was 'weight paint' :). Thank you google translator! Here are the analogical issues as yours IMO: https://blender.stackexchange.com/questions/76715/while-moving-arm-leg-mesh-messes-up and https://blender.stackexchange.com/questions/63381/mesh-doest-move-with-armature

The eyes and eyelashes probably share the weights that don't belong to the head/neck bones. You have to select every single bone of the rig and make sure they haven't got any weight influence on eyes and eyelashes (remove the weights from them as in example links above).


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Render is giving black and blank screen
In my scene when I render animation or photo they just go by quick and produce black images. Can someone look at my file and help me fix it?

I fixed it I went to Properties Panel> Render Tab> and under Post Processing Unchecked Sequencer.


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Why is 'bpy.context.active_object.pose' of type 'NoneType'?
It might be my inexperience of reading too much technical documentation or little experience in python, but, I'm having a bit of trouble reading the documentation. The command that triggered this confusion is:
bpy.context.active_object.pose

What is the Type of the options in the bpy docs, like in here:

Up until now I assumed that it was the type of the associated variable accessed from the module or the type inherited from, but, for this particular case, I'm a bit confused, from the interactive console:
>>> type(bpy.context.active_object.pose)
<class 'NoneType'>

but, the documentation gives it's type as Pose, which in itself is a class. Please explain what is this?

In itself is a class > None is a data type of its own (NoneType which is also a class) https://www.w3schools.com/python/ref_keyword_none.asp

That is because the object currently active or selected in the current context and defined in bpy.context.active_object does not have any pose data. It may not be applicable and thus NoneType gets returned by bpy.context.active_object.pose.

NoneType is the type for the None object, which is an object that
indicates no value. None is the return value of functions that "don't
return anything". It is also a common default return value for
functions that search for something and may or may not find it.

If the selected object or current active_object was the default cube, pose would be NoneType because pose data is not applicable to the default cube. An armature, on the other hand, has pose data and if the active_object was indeed an armature then bpy.context.active_object.pose would return the Pose object.

This is because, the object you have active in the current context, which is typically the 3D viewport , is not an armature. If it were an armature, then the type would be as stated in the documentation.

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


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How many points does the perspective in the viewport use and is it changeable?
I know blender can display both orthographic and perspective projection. But, when we look at a cube in blender's viewport, I'm unable to distinguish by eye, if the projection in the viewport is a one-point, a two-point or a three-point perspective. What does blender use, and is this something changeable?

Isn't the distinction between one-, two- and threepoint perspective just for drawing?
Dependent on the camera position, the 3D to 2D perspective projection will give you any of the three...

@haarigertroll ,  um... blender is basically drawing to the viewport, and the math seems to be different: https://people.eecs.berkeley.edu/~barsky/perspective.html

It's been a while since I had to calculate transformation matrices, but I think that the math is essentially the same, with just a different series of transformations. Take a look at these (same camera parameters, just different position gives you one, two or three vanishing points) https://i.sstatic.net/JKEx1.png https://i.sstatic.net/MZfTe.jpg https://i.sstatic.net/2PLcI.jpg

Addendum:
It actually says so on your linked website (last paragraph):
"Then the matrix for this 3-point perspective is: [...]
And, the 1 point and 2 point perspective matrices are special cases with 1/dx and/or 1/dy equal to zero."

I'm no architect, but this should only depend on your camera alignment.

1 point perspective - camera aligned to 2 axis
2 point perspective - camera aligned to 1 axis
3 point perspective - camera not aligned to any axis

As given in the link in the comment and mentioned by  @haarigertroll mathematically these are special  cases of the one point perspective.

Dang! Beat me to it... and nicely illustrated. :)

Thank you, Robin :).

But camera angle is the same as object angle to a matrix, so rotating an object will unfortunately break the illusion. :-(

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


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Why is "combine HSV" node showing different color with the same values?
I made a glass object and gave it a desired color, but now I want to animate its hue at the end of the animation (like and outro). So I used the "Combine HSV" node and used the exact same values to remake the color.

But here you can see when the color is remade in the HSV node using the same values, the HSV node is giving out a different color. (object preview on the left)

I have already decided on the first color and don't want to change it.
Why is this difference happening and how do I solve it.
Thankyou.

I am sorry this doesnt seem to solve the problem. I also dont understand how do I plug the value node to the inputs of the HSV node. That will just make it a bright red color.

Try adding a gamma node with 2.2 in between combine and bsdf nodes. I tried it and it seems to work.
The one on the right uses the other glass bsdf

I’d assume the RGB color picker is gamma corrected (to preserve the linear workflow), whereas the Combine HSV node as a - let’s say - more mathematical approach to color is not.
Add a Gamma node with a value of 1/2.2 between the RGB node and the Emission shader and you will get the same values as with the Combine HSV node.

Source: https://blenderartists.org/t/different-outputs-of-rgb-and-combine-hsv/675268

Maybe this should be brought to devs just to make sure it's intended and not a bug. And if intended, maybe there could be some detailed information on the official manual.

This did help getting the same color, thankyou for that. I also wanted to know what if I wanted the hue value to go round the color wheel and loop back to the same color in an animation. Usually I only go from 0.000 to 1.000 and it makes a color loop. But now that we are at 0.066 how do I make it loop? (Not really important but maybe there is a solution)

@Bits168 One way to go about it would be to use a modulus operator with a modulus value of 1. Then only the fraction part of given value will be taken into account (like this https://i.imgur.com/OkWXue2.png. Here the cube on the right has a hue value of 0.066, while the one on the left has 100.066. Should work with any value). Perhaps there is a way to do it with animation curves, but I'm not too familiar with animation.

@L0Lock It IS rather unintuitive. Although the issue appears to have been brought to their attention some time ago: https://developer.blender.org/T52772

Thanks for the link. « Maybe @Brecht Van Lommel (brecht) would love to revisit this at some rainy day tho » made me laugh


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Error when installing Blender 2.78
over the past few days, I have been trying to install "Blender 2.78" on Windows OS on 64-bit. The error is, I have insufficient permissions to download the software. Here is a picture:

Other information: I am logged in to the OWNER of the computer, or "ADMIN" of the computer. This is the only used account on my desktop computer.

I would explore that folder, and check why the user 'Amber', with role 'Administrator', cannot access it (permissions).

The fact that you use account which has Admin privileges which is the only one doesn't mean you have admin privilileges when running executables on Windows (and I suggest having 2 accounts one of which is actually admin). There is at least one more role configured by default which doesn't have privileges. Anyway this question is about permisions configuring on Windows and not Blender itself

Yeah like Dr Sybren said just use the zipped portable setup, much cleaner solution. Or if you insist rightclick on the installer and choose Run as administrator

You don't have to install Blender. Just download and extract the ZIP file and you can run it directly. There is no need for administrator privileges.

Yeah but now I can't open any .blend files :/

What does that mean? Can't you run Blender? From Blender, can't you choose File, Open? Or something else?

imho @BlueJEF means that  using zip archives ( I always do that) .blend files are not configured to open automatically (double click) with the zip version - hint: in this case you have to manually associate .blend files to your desired blender.exe after extracting the zip archive.

The problem occurs with the Blender MSI attempting to access the following locations, if you have previously moved your default user folders (such as Documents, Downloads, etc.) to another location.
This occurs even if you are a full Administrator on Windows 10.
The files the installer attempts to create in this location are:

C:\Users\[username]\AppData\Roaming\Microsoft\Installer\{E29A1273-2E7A-40E7-AA63-428A11D59429}\Production.ico
C:\Users\[username]\Desktop\blender.lnk
Uninstall Blender.lnk (unsure of folder)

Modifying permissions of the C:\Users\[username]\AppData\Roaming\Microsoft\Installer folder to add Full Permission to System will help, and allow you to progress and then skip the subsequent error messages.
I think the Blender installer may need tweaking to resolve.


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Cut out with correct UV/Material
I want to "cut out" a letter from a wooden material (image texture). I imported a letter as SVG and turned it into a mesh. Now I want the letter to look like it was cut out from the wooden board underneath, with the exact Texture Coordinates, so the texture of the wood and the texture of the letter match correctly. (My approach was to use the image texture from the wooden panel for the letter and play with the coordinates until everything matches but that does not seem to be an efficient method. Furthermore, it seems impossible to apply any image texture to the letter due its the "zigzag pattern". Any help is very much appreciated.

You can probably remove the "zig zag" pattern by using a Decimate modifier set to "planar" (View it from object mode - wireframe to see what it's doing before applying). The rest, you'll likely have to do with manual UV scaling/alignment.

The way to make it match the block underneath depends on the material used for that block-- you might consider including an image of its material nodes.  The top of the C should be easily matchable, but there's no simple automatic solution for the sides of the C.

You should be able to select both the letter and the plane underneath and unwrap them together, choose the Project From View option


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Simple deform only possible with z axis?
I am trying to bend a curve path using a simple deform modifier. But it's only working when I choose the "z-axis." With x and y, the modifier does not have any effect at all. How can I bend it using those axes?

Maybe this will help a bit

The modifier only allows bending when z axis is selected. To make the path bend around another axis, the path itself needs to be rotated.

Not quite true, if I understand what you mean.. see link in comment to your OP.


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Crowdrender Add-on cannot sync to render node
I have two PCs connected with LAN cables through a router. I have the crowdrender addon installed on both render nodes and logged in with my crowdrender account. Crowdrender recognizes the other PC with the correct name and IP address. But when I press "connect" I get the error message "sync failed". I have disabled the firewalls (eset internet security) on both PCs. I appreciate your help!

what about the router's fire wall?

@MartyFouts I disabled it and tried again.... no success still :/

You'll probably need to go to the crowdrender forums for help, because you're problem is probably network related.


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glitches an black pixel appear with
I use a particle system and an explode modifier to disintegrate two objects. For some reason, glitches and black pixels randomly appear in individual PNGs in the render sequence. In the rendered preview, the glitches are not visible. The glitches are definitely no "objects". They really are errors in the render. I am using ...
cycles
gpu compute
denoiser: optix
128 samples
motion blur: 0.6
... everything else is set to default.
Thank you for your help!

i think with seeing just a few settings it will be pretty hard to find the cause of this. Providing your blend file would help a lot...

it's super strange, the problem only appears when I import the scene in the video editor and render it out there. but it does not appear when I render in the scene itself. So I kind of got rid of the problem without technically solving it. I'm gonna simplify the file and upload it when the render is done... hopefully the problem then be replicable.

Should be closed probably as a bug https://developer.blender.org/T82036


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Bevel of a cube gives weird uv results in the corners
I want to model a simple room with round corners. For this, I have applied a bevel to a cube. The cube has a PBR material on it. When I unwrap the cube the corners do not have smooth transitions but visible lines. I have also tried smart uv and tried to change the uv map manually but I just can't find a solution to make the material seamless.

Blend File


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Why does my cycles-rendered heightmap have wrong values?
I've been trying to render a heightmap using cycles.
To that effect, i've set up:
1) A sculpted plane squeezed between -0.25 and 1.0 altitude (z-axis) in Blender.
2) An orthographic camera scaled to perfectly match the plane.
3) A cycles emission material set up in such a way that its final emission value is geometry.blue (z-axis position) -> math.add 0.25 -> math.multiply 0.8.

I render this to a 16-bit grayscale png image.

The issue is: The resulting heightmap's pixel values are slightly (or not so slightly) wrong - i.e, different from what the math should say.
For example, while math says that vertices at position ~0 in Blender should produce heightmap values around (0.0+0.25)*0.8 = 0.2 , in the resulting image, those areas are ~0.5; while math says that 0.94 should translate to 0.95, in Gimp when sampling those pixels i see their HSV Value as 0.89.
Upon some asking around in #blender, i've eliminated the following possible sources of trouble:

World (and its material)
Sky pass in render layers
Material color is set to 1,1,1
I've eliminated sections of the plane that violated the bottom boundary.

None of these fixed the problem.
If anyone feels like poking around instead of guessing around, i've also put the blend file to here.

This is probably due to blenders color management. You're expecting a linear relationship between the height of that part of the object and the colour of the pixel. However whilst the luminosity/emission strength of that pixel should be correct, when you render your image these values will be converted to an sRGB color space, and the values will not be correct.

What you need to do is set your display device to "None" in your colour management settings. This will leave your rendered values as Linear Values and not convert them to sRGB.

So helpful!! I've been struggling with gamma-correction problems for a while!


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Map ocean displacement to a sphere?
Is it possible to create a "spherical ocean" effect by mapping an ocean texture to a sphere?
I tried baking an ocean simulation, loading the .exr images as an image sequence texture, and setting it to a displace modifier with Normal enabled to displace along the object normals. That resulted in this strange effect:

Is it possible to do this properly, with evenly sized waves, etc.?

Update
I got this to work (partially) with a cycles image texture node set to box, and cycles experimental displacement:

However it's not quite what I expected..

You really love your oceans, don't you?

That was one of the first things I tried when the ocean sim was added ;-) I did think about reporting it as a bug. You don't need to bake out to images, you can get the same result by adding the modifier to a sphere and using displace instead of generate. It would appear that the ocean sim always displaces on the object Z-axis, while I believe it should work off the normal. Especially the displace option should not be restricted to only z displacement.

"Especially the displace option should not be restricted to only z displacement" I would agree, but change that to only the displace option. The Generate option starts by creating a flat plane, where all the normals are Z-up; displacing about Z and Normal are the same, while X and Y would do nothing but make a weird ripple effect at the edges.

@sambler I thought using a displace modifier would work because you do have the option to displace along normals (the ocean modifier does not, so I was using it only to generate the textures) however it does not work as expected. I'm not sure the displace option is entierly constrained to the Z, I have had "weird ripple effects at the edges" using it before.

@WChargin yep :) (I tried this before I knew about blender.SE, but only remembered it now with all the other oceany stuff going on..). About "weird ripple effects", I'm not sure the sphere is my question is getting displaced on the Z only, as it bulges out sideways as well as up and down. (see above comment as well)

@sambler It's not a bug. It's just flat mapping and a good method to put images on planes or other relatively flat surfaces.

@Haunt_House the generate option displaces on the z axis (that's fine) the option to displace existing geometry I expect to displace on the normals when it only displaces on z. I get it was made this way and wouldn't be a bug, but I think the outcome is not what a user would expect. I also get that displacing an ocean surface on an arbitrary surface may be difficult which is why I didn't report it as a bug. It would be a nice feature if it could be done. I do find it odd that baked displacement images also only displaces on z.

If I'm not mistaken, the Ocean modifier would have a hard time to calculate waves on irregular surfaces. It wouldn't know what to do if a wave hits Suzanne's ear because there's a very short way around the ear but a long way across the ear. Then the calculation would start to become a fullfledged simulation. Taking the detour via a displacing texture is ok.

  It looks as if you mapped the image flat. In order to produce a threedimensional texture, Blender projects the texture along an axis through your mesh. While your modifier displaces along the normal, the values it uses are generated with above mentioned method. That's why you get these stripes at the equator.
You might need to create a seamless texture to uvmap onto the sphere.
Turns out Blender can actually do blended box mapping with Cycles. Take a look at this link: http://mango.blender.org/production/blended_box/

Could you add more detail on how to create and use such a texture?

I'd like to, but I still think of how to do it effectively. And right now I'm so out of money that I'm starving a little. But I'll see what I can do.

Support for blended box mapping was added to the Image texture node in 2.64, so you don't even need a node setup. I'll test this out with ocean textures/displacement tomorrow.

@gandalf3 Did you ever tested it? BTW: Nice question.

@poor Yes, I put the results in the question..

@gandalf3 Ahh - I see. Sharp waves would be nice, but probably difficult to achieve.. I'll give it a try. Thanks.

Since the displacement modifier has an option to choose the texture coordinates, this isn't any different from the common problem of UV mapping a sphere.
I recommend some sort of blended box mapping using one modifier for each axis and blending between them with vertex groups.

I have tried using a UV sphere, unwrapping it with Sphere mapping and using that as the displace modifier texture coordinates. It results in a more even displacement, though it still far from looking like an ocean. Here is an image

You have the option to generate a new mesh for the ocean modifier or to use an existing mesh. If you create a sphere and apply the ocean modifier to it using the option other than 'generate' (sorry, don't have blender at hand right now), you can achieve your desired effect quite simply. This saves you from those mapping issues.

This only displaces all the vertices in the object along the Z, so it sort of makes it jump and wobble, but not much else.


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Is there a way to offset an edge? (extrude edge loop perpendicular to each edge)
I recently figured out how to do it with faces, but with edges, I can't seem to get it to work. I have a complex flat plane and i need to extend an edge loop. I tried setting to individual origins in combination with all possibilities for x,y,z axes in global and local, but it is still not extruding along the normals.

actual problem

simplified

exactly, since i am dealing with a plane-like surface

Is it like Inset edge?

yes, like offsetting an edge, thanks for clearing it up.

zeffii, thanks for pointing me in the right direction. the zmj100 pack has an addon that does an inset/offset of an outline (happy i saw it before it was deleted :). it is no longer the original one, but now it is called SIRE outline.

Your images are 404 errors now. In questions / answers here please use embedded tool to upload them. See https://meta.stackexchange.com/questions/75491/how-to-upload-an-image-to-a-post

ZMJ100 wrote an addon called SIRE outline. When installed it will appear in the left hand toolshelf in 3dview. It does offset (inset, outset).

https://vimeo.com/28147691 (demo video by tungee)
Over at BlenderArtists ZMj100 went crazy (in a good way) writing mesh addons, one of the addons does exactly what you want. It's probably not polite to link someone elses collection directly here, although I would like to. but here is a direct link to the thread and the zip is in the thread. It's all GPL license.

it's on the first page of the forum thread you posted.

I keep having to re-reference this. Seeming as the SIRE tools are not being developed (or perhaps called something else), here is an addon that I have recently discovered that works well: https://github.com/Bombaba/BlenderPythonScripts/blob/master/mesh_offset_edges.py

Just wanted to say thanks for this addon - have been looking for a script that would do this for ages!

Not working in 2.79. After the file is downloaded and installed without error, there is no related entry in 3D > Edit Mode > Edges menu.


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render different collections and put them together afterwards
I have a pretty heavy scene with several high poly objects which makes my PC already a little sluggish. However, I want to add some wind effects using a particle system. I was thinking about deleting everything out of the file except the lighting and camera movement and saving it as a new version. Then I would add the particle system, render it out and put the renders of the old and the new version together afterward using the Alpha Channel. Is that actually a thing? Is there a better solution to that problem?

Have you tried to do it with different collections, different view layers, and at the end mix them in the Compositor? It woul allow you to keep everything within the same file, and I guess if the collection is disabled for a given view layer, it should not affect the calculation speed


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How to capture UVs in Geo Nodes
I am trying to capture the UVs of a plant which I am building with geo nodes. In the Blend file, you'll find "Geometry Nodes.001" and "Geometry Nodes.002". The latter is the simplified version without branches. The linking between geo nodes and the material in the shader nodes seems to work. However I cant figure out how to get the UVs right. They are kind of stretched. I would like to capture the combined UVs of the branches and the stem of the plant. But I would also be happy just to get the UVs of the stem. Thank you for your help!
Blend File

@quellenform oh wow thats a beast of a node tree. But as for the simpler version, it‘s about capturing the uvs before the „curve to mesh“ node and combining them though „combin xyz“ right?

Yes, unfortunately, currently it is a "beast of a node tree", but I am working on a simpler solution. The problem is that Curve to Mesh doesn't generate UVs, and with cyclic splines you don't get suitable results via the point domain. I will release an updated version in the coming days, which will be a lot leaner.

@quellenform just tried to dive into your solution. amazing! keep up the good work man.


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slomo by rendering baked animation with higher frame?
I made a rigid body animation which I already baked to keyframes. Besides that, there are some other keyframes for camera movement etc. in the scene. I am editing the animation in premiere and I would like to use time remapping in premiere to slow the animation down at some point. Now I was wondering if there is a way to render the animation out with twice as many frames. I built the whole scene with 30fps.

I tried to increase the "time stretching" from 100 to 200 in the render settings which seems to have no effect.

If there is no way to solve this in the render settings, I was thinking about stretching all the keyframes since the animation is baked to keyframes. But it's like hundreds of keyframes which would be a pain to stretch them all. Maybe there is a fast way to do that?

I appreciate your help!

Why don't you just set it to 60 fps and then increase the time stretching? That way it will have to render more frames and will fit the sequence.


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Repeat (crop) texture at the edge of the UV island
I'm not quite sure I'm asking the right question, but here's my problem: I have this tile texture, but it contains a very high tile which I would like to get rid of:

I have highlighted in red the part that I'd like to get rid of.
However, even with the UV island scaled smaller than the texture, the whole texture is used:

Again highlighted the parts I would like to get rid of.
Node setup:

Object properties:

Check if the material uses UV as map, the scale of the texture is 1,1,1, and if the mesh has more than one UV map. If the material uses the UV map you are showing in the picture, everything will work as expected. If this doesn't solve the problem show us your material nodes and the vertices properties panel.

@joshsanfelici Edited in the info. Honestly, it makes sense that it doesn't work out of the box. When I load a repeatable texture, most of the time I want to use the whole image. And how would Blender know how to crop the image, especially when the island is irregularly shaped.

The Mapping node has the scale set to (3.0, 3.0, 3.0) change it to (1.0, 1.0, 1.0) and it should match your UV layout exactly.

@rjg But then it's not repeated at all.

The Mapping node's scale will repeat the texture, not the UV. So just imagine you create a 3 times bigger image in a picture editor and tile the texture 3 times. It will result a picture with the 3 red lines at the thirds. So you can't solve this problem this way. So what you can do is subdivide the face of the mesh and folding the UVMap on the edges. But in this way you can't resize the texture afterwards with the mapping node.

I'm working on something similar, trying to use one tiled texture for the whole model but still keep the tiling ability. Looks like yours just needs to change the mapping scale to 1 across the board and you'll be set.


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Close hole in object
I have this object that has a rectangular hole in it:

I would like to close the hole.
At first I thought I can just add a face at the top, add a face at the bottom and remove the faces that make up the inner wall of the hole. But the faces of the hole extend to outside of the hole, so I can't remove them:

My next idea was to put a box in there (the hole is perfectly box-shaped) and boolean it into the object. Unfortunately my Blender skills are insufficient to create a box with its corners snapping to the corner vertices of the hole.

Hello could you please share your file?

If that second image with the red arrows shows what happened when you tried to fill the top surface, you seem to have selected one edge from the top and one from the bottom of the object before trying to fill it! You should be able to do it exactly as you suggested. As @moonboots says please share your Blend file via https://blend-exchange.com/ following the instructions there to copy the full link on that page. Then edit your question here and paste the link into it.

The red arrows just show where the faces extend outside the hole, they're before any changes. I have added the file.

I found a way. It's a bit clunky and maybe someone more knowledgeable will add a better method.
Luckily some sides of the hole consist of whole :) faces. So I used those to extrude them into a box of the correct size.

First I had to extract the faces that I wanted to extrude. I tried Mesh > Separate > Selection but that removes them from the original object. So instead, I duplicated the object. There is no "duplicate" operation in the Outliner, so I used Copy followed by Paste.
I then selected the duplicate, entered Edit Mode, selected the faces on one side of the hole, did Select > Invert and hit Del > Faces to delete the rest of the object.

(The new object shown in Object Mode.)

With the faces still selected I activated the Extrude Region tool. At the same time I made sure that snapping is enabled and set to Snap To: Vertex.

I could now drag the yellow "+" circle onto a vertex opposite the faces, where it would snap, giving me a box of exactly the right dimensions.
After exiting Edit Mode I did a boolean union between both objects by using the new Boolean Modifier.
Finally I deleted the box object, leaving me with the "repaired" object.

I assume that object wasn't originally made in Blender? Before you started you should have used Mesh > Clean Up > Limited Dissolve in Edit mode to get rid of most of those spurious edges, however filling the top and bottom faces works fine without doing that.  If you want to remove all 4 inner faces, connect the two bottom vertices on the right hand side with 'J' and then you can select all the faces and delete them.

@JohnEason Ooh, that Limited Dissolve is nice. It was made in SketchUp and I imported it as an .stl into Blender.

Yep. It can make a big difference!


text:
how would you texture map a rope?
I would like to make a rope for a game object (so it should be fairly low poly). I know how to divide a cylinder into segments (K key with Z key) and form it around a nurbs path.
for my game engine (unity) my textures have to be powers of 2 and square, so 128x128, 1024x1024 etc, so it would not make sense to use a huge texture with just a thin line used. i need to use the same square rope segment texture over and over again on each segment.
I would like to texture map a segment of rope to each segment, I'm still playing with photoshop to produce the perfect tileable, seamless rope fragment texture, but assuming I work that out, do I have to select each segment and use the uv smart project on each one, or is there a quicker way to do the whole lot.

Create a bezier curve in the shape of your rope.
Create a rope segment with some seamless texture.

Make sure that the bezier curve and the rope segment have origin in the same location.
For the rope segment add Array modifier, set length to Fit curve,
select your bezier curve and tick Merge so it won't generate vertices doubles.
Add Curve modifier and select your rope segment.
Now you should have something like this:

Close the ends of the rope model.

thanks but i should have added that my textures have to be powers of 2 and square, so 128x128, 1024x1024 etc, so it would not make sense to use a huge texture with just a thin line used. i need to use the same texture over and over again on each segment. the bit about the making the curved cylinder i already have.

I would remove the last step. (All though that was the only step that I completed)

OK, edited, it seems like some fun is not allowed here.

You can enable 'Merge' on the Array modifier so you don't have to remove the doubles manually.

Oh, I didn't know about that feature - thanks, I have edited my answer according to that.

steveh - I am sorry but don't get your problem. Yhy can't you use your 128x128 texture the same way as in the example I have posted? The texture in the example is also small, square and power of 2 ... it just repeats (tiles) over the whole model.

i think my best options is to create a macro to do the selection and uv mapping, then at least each segment is only one hot key
https://www.youtube.com/watch?v=zMxkU350SaE
i haven't tried it yet, but it looks like a useful thing to use


text:
how to move, rotate and scale multiple objects in edit mode
I can only go into edit mode on one object at a time in as far as i can figure out.
So if i have 10 objects, is there a way to move, rotate or scale all 10 of them together in edit mode?
I don't want to do it in object mode as that does nothing to the meshes and when i export fbx, all object mode stuff is gone.
thanks

You can modify your objects in OBJECT MODE, then apply the transformation to the mesh (CTRL + A).

that works great but i've noticed a side effect. when i export to .fbx then import into unity game engine, i can't rotate in Z anymore. rotate in X and Y is fine, but Z rotation moves X. this only started happeneing after i did the ctrl-A. its probably more of a unity question but can anyone think why this is happeneing? thanks

I've just tried (blender 2.78 + unity 5.5) and the objects rotate in X,Y and Z correctly. As you say, maybe it's a unity setting or something like that.

When scaling make sure you don't have all axes locked for scaling. Otherwise you won't even see the gizmo.

In blender 2.8 you can select multiple objects and go into edit mode.
If the meshes not rotating in object mode, may be manipulate centers icon is on, make sure it is disabled.


text:
Can you use instances as part of a skin?
I made this limboish guy to learn how to create armatures.

I thought I would use instances for the hands, so that when I make changes to the hand mesh, both would update.

After which I learned that you cannot use modifiers with instances. Since being deformed by an armature is a modifier, this seems to mean that instances cannot be part of a skin.
Is there a way to use instances as part of the skin of an armature?
(One way to overcome this would be to "make duplicates real" and then apply the modifier. That would defeat the point though, as changes would no longer be reflected in both hands.)

Why you need to apply the modifier to the istances in this case?

@Carlo How can I get the hand instances to move when I pose the hand bones, unless they have the Armature modifier?

By adding to your object an Armature modifier, as you did. But I'm asking why you would like to apply it, which is the thing that gives you problems.

@Carlo Ah I shouldn't have said "apply", I meant just adding a modifier. You can't add modifiers to instances, so I don't know how to use an instance with an Armature.

Sorry, but I can't understand properly what you are saying. You do can add modifiers to instances. Why you say you don't? Can you make an example?


text:
How do I make every vertex to be associated with the same number of bones?
If I want to make every vertex to be associated with three joints, no more or less, is there a way that doesn't involve manually setting the vertex?

There is an operator called Limit Number of Weights per Vertex:

Limit deform weights associated with a vertex to a specified number by removing lowest weights

Operator call in Python:
bpy.ops.object.vertex_group_limit_total(group_select_mode='ALL', limit=4)

You can find it while in Edit Mode of the parented mesh,
in the 3D View T-toolshelf > Tools > Weight Tools > Limit Total.
Or you go to Weight Paint mode > Weights menu > Limit Total.

Does this operator make the same lowest and max number of bones to associate with each vertex? If I set the Limit Total to 3, all the vertices will have at least three weights and bones, but not more than that?

If a vertex has a weight of 0.8 for Bone, 0.5 for Bone.001, 0.3 for Bone.002 and 0.2 for Bone.003 and you run the operator with a limit of 3, the vertex will be removed from group Bone.003 (so no weight anymore).

Is there a way to make the vertices have at least a certain number of bones to be associated with, not only the max number they can have?

No, like the name suggests, it limits the maximum number but does not enforce it - it's impossible. How would it be supposed to assign vertices to groups? Randomly? Based on proximity? There's no clear solution.


text:
Blender rendering fileformat: .file
So i have made a video and i started rendering in AVI format, codec H.264 with MP3 audio and when I'm finished rendering it's just a .file file. If I open it using windows media player it runs, sometimes.
Ps: I'm saving it as a H.264 and i have used it before...
Extra information:

Video Format:
720p (1280x720)
50 FPS
Raw video from a USB 2.0
Raw video format: 720p (1280x720) 50 FPS Bitrate: 4785 AVCHD-video
Encoding:
Format:AVI
Codec:H.264
Bitrate:6000
GOP Size:18

Um what are you saving it as....? As long as the format is valid you could just manually change the extension.

H.264, but i have used the exact same setup before and it worked...

That is quite odd! could you upload a .blend with a service like http://pasteall.org/blend so I can take a look?

Sure! Just a monet...

It doesn't want to upload... :/

Try filedropper.com

There we go:http://www.filedropper.com/filmprojekt

...looks correct to me, could be a bug :/

uuuurrr... And I have a deadline for a vid...
Well thanks any way :)

Have you tried manually changing the file extension? You'll need to make sure that windows doesn't hide file types from you. Just right click, rename file, and add the extension yourself, whatever you originally rendered. If you don't see file extensions go here : (http://www.pcworld.com/article/241051/how_to_view_hidden_files_and_file_extensions_in_windows.html)

You should render your animations as a video sequence. This has several advantages. If your render crashed, you will not have to re-render from frame 1. You can always convert the image sequence to a video later.


text:
How do you export GLTF from Blender?
Is there a way to export GLTF or do I need a plugin or something? Thanks!
Benjamin

Check out this tutorial on how to export your assets from Blender to WebGL/glTF 2.0

The glTF-Blender-IO addon ships pre-installed when you download Blender 2.80 or higher.  You can find it in the File -> Import and File -> Export menus, and both the *.gltf and *.glb (Binary bundle) forms are supported.
If you can't see those entries in the menus the addon may be installed but disabled in user preferences. To enable it go to Edit > User Preferences Add-Ons, search for GLTF and enable the addon GLTF addon.
If nothing is listed after searching you may have to download and install the addon.
The glTF file format is intended to be a last-mile transmission format.  The data is stored in a manner similar to how a modern GPU expects to find its own graphics memory arranged (with vertex attributes etc), meaning that glTF can be loaded and almost immediately rendered even on mobile devices, in WebGL, without a lot of pre-processing.
The material model in glTF does not support all of Blender's complex shader nodes.  Instead, glTF offers a principled PBR (Physically-Based Rendering) material definition, and the importer/exporter does its best to translate this to/from Blender's Principled BSDF node according to some very specific rules.  The rules for this are laid out in the Blender Manual.

This is the Water Bottle sample model.  This model and other samples can be downloaded from the glTF Sample Models repository.  The glTF-Binary/*.glb form is typically the best version of any given model to download, as it bundles all the model's assets into a single file.

You need to install a plugin.
The official export plugin from Khronos Group can be found here.

I just downloaded the but I can't get it to work. How do you instal it in Blender?

Tried this yet? https://github.com/KhronosGroup/glTF-Blender-Exporter/blob/master/scripts/README.md


text:
BGE - Can't move characters by holding down sensor key
I started making a simple Blender Game Engine project in which I have movement sensors connected to my controller (a Python script). My script says:
if sensors["space"].positive:
    owner.applyMovement([0, 0, 4])

so basically it will go upwards at a distance of 4 on the Z-Axis. However, I can't keep going up by holding down the key. I have to repetitively tap the key.
How can I allow holding down the key in order to move?

you need to activate True level triggering (pulse mode) with your sensor in the logic editor, it's a button with label like this ''' and you will be happy!

When you use an AND controller and a motion actuator, you do not even need [true level triggering]


text:
Pack all into .blend file changes material outcome
I did a few tests now and so far nothing works except if I change the material entirely, which I do not want to do.
Basically, I have finished my project and need to render it, and I want to use a renderfarm (SheepIt in this case) to save several days/hours. So I need to Pack everything to into the .blend file.
I placed all the textures in same root folder as the .blend file.
The .blend file is in this location:

D:\Program\Blender Foundation\Project Folder\Landscape

All my textures are in this folder:

D:\Program\Blender Foundation\Project Folder\Landscape\textures

Different objects textures have sub-folders:

D:\Program\Blender Foundation\Project Folder\Landscape\textures\Shaft
D:\Program\Blender Foundation\Project Folder\Landscape\textures\Shield
D:\Program\Blender Foundation\Project Folder\Landscape\textures\Sword
D:\Program\Blender Foundation\Project Folder\Landscape\textures\ToonLinkBody
D:\Program\Blender Foundation\Project Folder\Landscape\textures\Navi

On SheepIt.com:
When I upload without pressing this: File > External Data > Pack All into .blend
I get this warning: Cannot find file. and it spams all the textures missing.
When I upload, having this pressed: File > External Data > Pack All into .blend
I get no warnings. But the rendered picture at the end looks like the shading is totally weird, as if the material drastically changed itself.
But! I still get the results below when I render on my own computer:
Picture 1: Without File > External Data > Pack All into .blend
Picture 2: With File > External Data > Pack All into .blend
What am I doing wrong. Why does packing change the glossy/light on those specific materials? I thought packing a blend file, everything would still look the same. To get a decent result with packing, I had to tweak my materials alot, and I am still not happy with them comparing to the "original" if you know what I mean.
Is it only these 3 objects in the entire scene that gets affected by packing into .blend
Toon Shader Diffuse
Toon Shader Glossy
Mix Shader.
Diffuse Map (color)
Normal Map

Sounds like a bug, that shouldn't happen. If you can recreate it and provide a file showing the issue you should report it.

I uploaded the .blend file on a simple upload page:
http://pasteall.org/blend/index.php?id=48879

Opened new scene.

Imported object (One of those wierd after packing).

Changed Lamp into Sun.

Rotated Sun for similar angle as in my project.

Rotated object for similar angle as my project.

Added sky texture under World. Surface: Background Color: Sky Texture

Checked Ambient Occlusion, changed factor to 0.10.

Changed Strenght of sky texture to 2.5

Pressed File>External Data>Pack All into .blend

Uploaded .blend file to this forum

I edited my objects textures abit. Still same parts of the textures!
Almost identical scene settings in a .blend file
At point 8, the scene lights and material almost look identical to my projects
At point 9, same thing happens, everything gets dark in render and in preview window render.
Something with the material Nodes aint co-operating with the packing function, which makes no sense to me, as I mentioned above. Packing files into the .blend should not affect the material itself. Changing the material settings should change the outcome, nothing else. Don't you agree?

You should use https://blend-exchange.giantcowfilms.com instead because pasteall deletes the blend file after a period of time.

I have had similar issues with packing files into blend. I have found that my lighting is corrupted while packed, but if I unpack the blend after I've moved it to wherever it needs to be the lighting goes back to normal. So pack -> move -> unpack -> save -> render


text:
Why does swapping the X and Y mapping coordinates break 'box' mapping?
Can anyone explain why swapping X and Y coordinates breaks box mapping?
Logically, I was expecting it to just mirror the image. It works top down but not on the sides?

The Box mapping uses the direction of the face to determine the mapping. This means that the faces parallel to, say, the Y-axis are mapped as X,Z to the image's coordinates, while those parallel to the X-axis are mapped as Y,Z to the image's coordinates.
By swapping the input coordinates in that way you are upsetting the mapping so that, say, for the faces parallel to the Y-axis are mapped as Y,Z to the image's coordinates - but since the face is parallel to the Y axis, Y is constant - so the image becomes distorted on that face (as only one axis of the image coordinates varies; the other is constant).

Another way of looking at it is: the box mapping algorythm works only with the actual object space. It uses surface normals and their coordinates are not changed according to how you change the object space coordinates. It expects original object space coordinates and stops working correctly if it gets anything else, because it also uses normal vectors that remain the same when you change object space. You can reconstruct box mapping with nodes to be able to control normal vectors it uses as well. If you changed the noramls in the same manner as the object space it should work:

I've tried this but it's still not doing what I was expecting. Although I noticed the useful Rotate Vector node group, would be useful as a built in node.

What is it that you were expecting?

By flipping the X & Y it is mirroring the image, so in the case of your example the arrows would rotate 45 degrees. This works on the XY plane but as explained in Rich Sedman's answer it won't work on the sides of the cube. Rather naively I thought box mapping took just one plane and re projected this on all sides.

Yes. That is what happens because box mapping does not take your change of the object space into account. However, if you have a look, my example has the normal vector changed as well, so it works. Or you could delete the split and combine vector nodes at the beginning of Normal and Object outputs and flip the texture with the big Vector Mapping node in a frame that says 'Do whatever you want to the texture' You can just scale X by -1 for example, or as it says do whatever you want with the texture that is mapped to the box.

Martin, FYI, I've added a patch for a new Vector Rotate node. See: https://developer.blender.org/D3789

That's interesting. Would it not also make sense to have a full mapping node that would have inputs? I think there are no reasons to have the mapping node as it is right now.

The mapping node would need at least nine inputs, so from a UI perspective it would be even bigger or need redesigning. At least with this node it keeps things simpler.

The mapping node already has more than 9 inputs, they are crippled and nothing can be connected to them. There are great many examples where inputs like that can be very useful. The node is also the only one like that and is not consistent with the rest of the nodes. As for the number of inputs - Principled BSDF has 20 of them and it's fine. I think a very strong case can be built about the current mapping node not being logical at all. But the separate rotate translate and scale nodes are really great as well.


text:
Getting a Bleach Bypass Look in the Compositor
What nodes should I add and what should I change in compositor to get a good bleach bypass film effect?
I would like to have a precise description of all nodes (for example, contrast-10).

Could you add an example photo/video of what you want?

http://www.pixelphotoco.com/wp-content/uploads/Special-Effects-3.jpg -something like that. You know, i would like to make my video professional looking.

The way the question is currently phrased, it sounds a bit subjective to me. (what is "good"? what is "professional"?)

i show the photo, i would like to get the same effect

The "bleach bypass look" can be replicated in its most simplest way by reducing saturation and increasing contrast of the image using bright/contrast node.
But instead to get a more detailed look what I would suggest is to:

have the image de-saturated slightly
have a copy of the original image de-saturated completely and boost
the contrast of this layer by carefully using an RGB curves node
the monochrome layer should be mixed with the first image using
"overlay" blending mode.

To adjust the contrast effect you would adjust the curve as desired and also the factor/strength of the mix/overlay node.

Full Size
In your example image the artist appears to have also used some sort of sharpening or detail enhancement to make details pop out more.

Here is a quick attempt to get a similar effect to the reference image:

full version


text:
How to distribute the objects on a sphere evenly?
I want to replicate this mesh - https://youtu.be/lBMhGZ-iprw?t=16m27s

I think the best way is using a particle system of cubes. So I need to create a sphere of simple circles. It is necessary that in each circle the vertices are at equal distance from each other. But I don't know how to create those circles.

May be helpful: https://blender.stackexchange.com/questions/65395/repetitive-carvings-holes-around-a-sphere

Thx, but he used Ico sphere, and vertices are not aligned on a horizontal axis.

Possibly interesting: https://bendwavy.org/sphere.htm . Not listed there is a paper that I can't now find, a doctoral thesis at Univ New South Wales iirc, about partitioning the n-sphere into equal cells with lines of longitude and latitude.

You can do it using both dupliverts or particle system, but you have to prepare the mesh properly first.

Add an UV Sphere with default settings (I use these in this example) and delete the bottom half of it. Select the very first top edge loop, press Shift+S-->Cursor to Selected, then add a circle and set its vertices count to 6. Enable vertex snapping tool (magnet icon) and snap it to the default edge loop. Do the same with the lower edge loops, but this time add the circle with 6 more vertices. Delete the default loops with X.

Repeat the process until you get to the sixth edge loop (It should be 32-vertices default loop). Every lower edge loop should get 6 more vertices- I know it's a silly work but I don't know how to script ;P. Add a cube in the middle of the sphere.

In Object Mode select the cube, then the sphere, press Ctrl+P-->Set Parent To-->Object.

Select the half of the sphere and give it the Mirror modifier (Z axis).

Finally with the sphere selected go to the Object Data header (Duplication panel), select the Verts window and check the Rotation checkbox.

Thx, it was very helpful and helps me to replicate this effect in Unity! But I wonder, is there a script somewhere for creation those circles with perfect accuracy. Or a formula in case I want to create a sphere with more than 32 vertical loops.

@PlanetControl I am curious if the script may work in this case too :) (I've mentioned it in my answer). I've also asked a question about it: https://blender.stackexchange.com/questions/78817/how-to-create-a-sphere-with-different-ring-vertex-count-by-scripting Hope some scripting magicans can aswer it :).

Thanks to the efforts of amazing coders here you can now edit the sphere's rings number and it all work perfect :). Please check it out: https://blender.stackexchange.com/questions/78817/how-to-create-a-sphere-with-different-ring-vertex-count-by-scripting


text:
How to make a material not reflect light?
I have 2 Finishes in cycles,
1) with a glossy >> roughness is 0.5 (Lets call this as
Roughness0.5)
2) with a glossy >> roughness is 0.05 (Roughness0.05)
I want roughness0.5 to reflect light.,
but
I dont want Roughness0.05 to reflect light because the light reflection looks weird here.

At the same time, I can't turn of the glossy in the cycles settings for an object for any chance.
Is there any way to do this?
Do I have to play with the light path nodes?

I believe that the whole nature of shaders is to reflect light back at the camera (just as real life). If you want a material to just absorb light, you could make it a #000000 colored emissive shader.

Please find what exactly i need here..
https://scontent-sin6-1.xx.fbcdn.net/v/t1.0-9/15590505_1222508567845994_4984324993204822974_n.jpg?oh=e37449f09c742d12f7198ad8be47b7cf&oe=58EA1871
i need the specularity on the object (as marked in blue)
But i dont need miror to reflect light (as marked in red)
So, there is anything to do with material?
basically, the left sphere will be a half glossy wood.

Cycles doesn't work that way. To make it not look weird, use real lights (like an hdri, not a simple point or plane).

Possible duplicate of Exclusive lighting

Try using a Toon Shader instead of Glossy one. It's not the proper, accurate way of doing this IMO, but the final result is close to what you're looking for I guess.

Use a Lamp instead of emission plane.

Set the Toon Shader to Glossy and decrease the Size to 0.001 and Smooth to 0.000.


text:
How to make a net of nodes in blender?
How can I make a net of nodes like this:

Here's the reference video example: https://youtu.be/rTzGMcOd8D0?t=7
I know it's possible by extruding the curves and joining them. But I want to make it quick.

You want to make it in Cycles or Blender Internal Render?

i want to make it only in cycles

I got the answer from here https://www.youtube.com/watch?v=muJvHClqYi8
That's really nice.
if FasterTutorialsCom are watching this a big thumbs up

You can generate really cool net type effects with the Animation Nodes addon as well.

I think the link @Computer Guy provided solves the problem, but as the link-only answers may become invalid I post a step by step solution how to do it (which uses the Wireframe Modifier, dupliverts/particle system and Camera DOF).

Create a mesh you want (in my case I use a poor Suzanne again :)) and triangulate it with Ctrl+T. You don't need to do it though if you want to have a quad based wire.

With the object selected go to the Modifiers header and give it a Wireframe Modifier. Set its thickness as you like.

Select your mesh and give it an Emission shader in a Node Editor (material). Set its Strenght value as you like. Also set the World color to pure black.

Now select your mesh, press Shift+S-->Cursor to Selected. Add a Sphere there (make sure it shares the same origin point as your mesh). Scale it as you want then press Ctrl+A-->Rot&Scale to apply transformations to it.

Now select newly added Sphere, then your mesh and press Ctrl+P-->Set Parent To-->Object. Select your mesh in Object Mode and go to the Object header-->Duplication panel and press the Verts button.
NOTE: You may achieve the similar result using the Particle System, but I won't cover it now (maybe I'll edit my answer to explain it later).

Set a material of a Sphere as pictured below (mix an Emission and Transparent shaders). Play with the Factor of a Mix Shader to fit the reference.

With your mesh selected in the Object Mode press Shift+Ctrl+A to make the duplicated Spheres a real/editable objects.

Finally select your Camera, go to the Camera Data header-->Depth of Field panel. Use a dropper icon to select one of the spheres that is closest to the camera and increase the camera's Radius size a bit. It'll blur the background as in the reference you provided.

A good answer to my question

I created an Icosphere, scaled it up, deleted all the edges, duplicated it, and then used this script to connect every vertex to every other vertex:
import bpy
import bmesh
import sys
# from time import sleep
import time
from math import floor

# wiremess.py
# connects all nodes of an object
# This script is hereby released into the public domain. Feel free to use it in your own project.
# ignore all the commented-out code (:

obj = bpy.context.active_object

bpy.ops.object.mode_set(mode='EDIT')
bpy.ops.mesh.select_all(action='DESELECT')

mesh=bmesh.from_edit_mesh(bpy.context.object.data)

mesh.select_flush(False)

sys.stdout.write("\nWiremess.py\n");

prgpos = 0
prgmax = len(mesh.verts)**2 ## because of looping through all, twice

# while i < len(mesh.verts):
for a in mesh.verts:
    # sys.stdout.write("i: "+str(i)+"\n");
    # while j < len(mesh.verts):
    for b in mesh.verts:
        # a = mesh.verts[i]
        # b = mesh.verts[j]
        if a != b:
            # sys.stdout.write("Connecting "+str(a)+" and "+str(b)+"\n");
            sys.stdout.write("\rProgress: "+str(floor(10000*prgpos/prgmax)/100)+"% ");

            a.select = True
            b.select = True
            mesh.select_flush(True)
            # sys.stdout.write("# of selected verts: "+str(len(
            bpy.ops.mesh.edge_face_add();
            bpy.context.scene.objects.active = bpy.context.scene.objects.active
            a.select = False
            b.select = False
            mesh.select_flush(False)

            # bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1)
            # time.sleep(0.3);

            prgpos+=1;
        # }
        # j+=1
    # }
    # i+=1
    # sys.stdout.write("i incremented, now "+str(i)+"\n");
# }
sys.stdout.write("\n"); # to terminate progress meter
sys.stdout.write("Done\n");

Then I added a material and set the draw type to Wire.
On the second "icosphere", I created another material and set it to Halo. You can then tweak the colors appropriately.

You can create an IcoSphere.
It is the best object you can start from.
Go moving the vertices.
Use the K key to create more edges.
And Mesh>>Faces>>wire frame to turn it to lines you can render.
Some Images below...


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Transforming (morphing) one object's shape into another's
For example, I have two different objects. One cube and another- sphere. Can I somehow make cube change its shape identical to the sphere through animation? I mean I can do it manually with shape keys but is there some way to do it procedurally by just having start and final shapes even with different amount of vertices? The thing is I have two much more complex objects and transforming one into another is a hell of an ordeal.

Procedural way with shape keys for 2 objects is Join As Shapes option in the Shape Key panel (object must have the same vertex count). Cast modifier could be a way for transforming 1 object (although likely not any shape as complex ones can become a mess). One more way is with Keyed particles but that will mean breaking objects into particles obviously. It all depends on what transition are you going to with and how complex objects are.

Morphing objects with different vertex count is impossible AFAIK with the blender tools, unless you use a scripting. Here's a temporary solution though. It uses a to sphere tool.

I have three objects here with a different vertex count. I'll use a sphere as a midpoint for all transformations.

Add a shape key (Key 1) and set its value to 1.000. Enter Edit Mode and use To Sphere tool (Shift+Alt+S,1). Then hit Ctrl+V-->Smooth Vertex. Hold Shift+R to repeat it (set smoothing value to 1.000 in a Tool Shelf) unless the vertices are relaxed. Then repeat the to sphere operation.

Do the same with the other objects (every one should transform to the sphere of an equal size). Finally keyframe the shape keys values and visibility of the objects on a timeline.

Olav3D has a great tutorial on transformation animation using shrinkwrap modifiers:

I asked a similar question on Blender StackExchange, answered here.


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How can I UV Unwrap a Minecraft box model?
I'm trying to create the character from game Minecraft. It's simple and I finished it. Now I want to unwrap it like its texture file:

As you can see it's small (on size too) and it's box styled too. But when I try to unwrap for example face, I get a circular output... How can I unwrap my model like that?

You have to mark seams to create the unwrap like this. Select the edges you want to place seams on, then press Ctrl+E-->Mark Seam. For more tips about how to place seams right see: How to Place the Right Seams for UV Unwrapping. After placing seams to one side of your mesh apply the Mirror modifier. Alternatively you may start from appying it and then mark seams.

Next select the whole mesh (A) and press U-->Unwrap. As you can see you get the result similar to the one you provided. If you want to make it identical you have to experiment with seams placement.

Here's the .blend with my seams placement example:

Smart uv project would work quite well for this.

You can also adjust the island packing quite easily like this:

As a side note, you'll want to get rid of those verts in the middle of the object.
Here is my blend:

(As for unwrapping to the image, I think it would be far more difficult than just repainting as it's only a few pixels anyway...)


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how to make a custom shape for force field
There are a bunch of options for the shape of a force field like point or plane but I want to apply the force field to a custom shape, let's say a cube. The reason is:  I want hundreds of objects to be attracted to the cube to eventually FORM the cube.  Kind of like particles.  However, I don't want particles to be emitted from the shape but rather to be attracted to the shape to eventually form it.

i am not totally sure but i think this is not "just a visual" shape but the working shape for the force. I assume you cannot change the visual shape for a force field.

Hello, can you please tell a bit more? Are all the objects the same? Are they agitated or do they come straight to the cube? Etc

You could put all your objects around your cube, push them away with a Turbulence,, then bake the simulation, and invert it in the Dope Sheet

The cube. You can use the surface option for the force.  The cube can also be an obstacle, this is important.  People often emit particles from a surface and then reverse frames.  There are some other options as always.  You might consider showing your work so that a potential answer does not explain things you already know.

Particles have a built in feature where the particles assume different shapes.  You can investigate this in the particle panel.  This motion may be rather linear.  This may or may not suit your goals.

You can also write a Python script to move objects/children along various curves for nonlinear motion. You should observe that isolated forces will not easily cause particles to assume the shape of some target either in some linear fashion or  without obstacles. You may want to state if linear motion is acceptable. For rather flowing curved effects, you will need multiple forces/keyframes.  Everywhere, all at once.  You may also want to show an example image/video.

you have the keyed particles that could fit your needs but you don't give enough details


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Recalcualte automatic weights for single bone using python
In a blender add-on, I import a mesh and join it with an armature using automatic weight.
I use bpy.ops.object.parent_set(type='ARMATURE_AUTO', keep_transform=True) for this.
However, I then need to add an additional mesh to the the main object and recalculate the weights for only a single bone (this to avoid weight painting for other bones influencing the additional mesh on poses)
In the post How to recalculate automatic weights for single bones?, it is described how to do this manually.
However, I'm unable to identify method to trigger this from python code.
Is there a suitable method for this in the blender API ? Or is there some way of triggering a select of a UI menu element from python code (for example some general function within the https://docs.blender.org/api/current/bpy.ops.html namespace)

You can use the info panel in blender to quickly find the python commands. If you cannot find the info panel, it is on the bottom left on scripting tab. It logs out every action you perform. Do it manually and find whats logged there. I got bpy.ops.paint.weight_from_bones(type='AUTOMATIC'). hope this helps

Awesome, just what I needed. Thank you ! Would you mind adding this as an answer so that I can mark it as the correct one ?

You can use the info panel in blender to quickly find the python commands. If you cannot find the info panel, it is on the bottom left on scripting tab. It logs out every action you perform.
Do it manually and find whats logged there. I got bpy.ops.paint.weight_from_bones(type='AUTOMATIC').

Hope this helps


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Weird box that I can't get rid of on the viewport

When I made alt b this red box outliner showed up and no matter what I do I couldn't get rid of what should I do. I restarted blender and nothing has changed.

CTRL- ALT-B should  get rid of it.

exectly all I need was hold ctrl thank you !

In the viewport:
Press Ctrl + Alt + B to remove a render region.
Press Alt + B to discard a clipping region.

You are right! I will update my answer. Thanks


text:
Moving a vertex makes only half of the connected faces move in the right way
Sorry if the title doesn't accurately describe my problem, I am new to Stack Exchange. I need to make all the faces move up equally, but the ones circled in yellow only move up half way, while the ones in red are how I want them to move. This has happened to me multiple times with different models and I am trying to find a solution

Hello :). The problem is called non-planar faces (if you want to read up on it). Triangles always stay planar, so they might work better in this case.

https://blender.stackexchange.com/questions/56755/flat-quads-or-why-is-my-mesh-so-funky/56764#56764

Your problem comes down to changing the internal triangulation done by Blender, as described by Robin Betts here: flipping internal triangulation
In your particular case: select problematic faces, Ctrl + T to triangulate, change Quad Method to Fixed Alternate, select the new edges and dissolve them:

If you want to make a script automatically fixing such quads, this could be a starting point: Select concave quads

I thought of a similar situation, but I decided to tell about proportional editing since it would  be a less complicated way for begginers and did not deal with fixing improper meshes.

The best solution is proportional editing. Press 'O' or that little icon on the top highlighted in the image below. Then when you move a vertex you will see a circle around the vertex you have selected. The size of the circle is controlled by the scroll wheel on a mouse. The bigger the area the circle is, the more strongly the other vertices will move with that single vertex.

I disagree this is the best solution, I even doubt this is at all a solution the OP is interested in, however it could be helpful to other visitors finding this thread through google...


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Why are my objects invisible and in the wrong places?

When I add an object, it is invisible. When I change to evee, it turns black, and when I move around the view, it takes away from the black and makes it grey. Then when I turn to cycles it turns grey like in solid view. I've already tried rolling back my drivers, and it doesn't effect anything. I am using Blender 2.81. Everything was normal for a while, then all of the sudden I added an object and it was invisible.
When I restarted my computer, it did the same thing but only when I was close. The origin and outline are still there. My clip start was set very low, but even when I change it it didn't change anything.
One time when this was happening, I deleted everything, then added a new cube. It was displayed as one of the old cubes, but the outline was not in the right place.
When I add more objects, some of them disappear and others display the wrong shape. This only happens in object mode, and going into edit mode fixes it.
This only happens every so often, and seems to just magically be fixed.

For the out-of-place issue. Your Origin is not centered on the Object. Select the cube when in Object Mode and use this tool to put realign the origin


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Decimate f-curves using python
In blender 2.82 I want to decimate all the f-curves in active action, how can I override the context to make the script work with Animation Nodes Script Node?
import bpy
if decimate:
    bpy.context.area.type = 'GRAPH_EDITOR'
    bpy.ops.graph.decimate(mode='RATIO', remove_ratio=0.92)

Like this:
import bpy
def simplify_fcurves():
    C=bpy.context
    old_area_type = C.area.type
    C.area.type='GRAPH_EDITOR'
    bpy.ops.graph.decimate(mode='ERROR', remove_ratio=0.698113, remove_error_margin=0.5)
    C.area.type=old_area_type
simplify_fcurves()


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Is there a way to unwrap multiple objects into separate UV space?
In 2.8+ the multi editing is a thing - and it's awesome! But sometimes I do not want to create atlases - I just have many many objects and just want to batch-unwrap all of them in one click without having to enter edit mode on all of them one by one.
Is there a way to do that without making a custom script?
Basically I wanted to select a bunch of objects and do Smart UV Project on them and be on my way, but that does not seem to be possible (the only one that can work that way is Lightmap Pack with "Share UV Space" option unchecked).

Seems like there is still no built-in way to do this and you have to use a script, as described here:
Smart UV Unwrap Multiple Objects
I made my own script that does that and shows up in search to make it a bit nicer than having to click "run script". Just look for "Batch Smart Unwrap".
It will create a UV map if none is present, otherwise it use the currently active one
https://gist.github.com/orels1/2405f2fbc6a3b0950b8f65881db1b567

You could join them - In Object Mode Hold down SHIFT then Click on each object. THen SHIFT + J will join the objects, the UV unwrap

That will make them all share UV space though. I just want them to be unwrapped as if they were separate objects, but without having to click every single one of them and hit "unwrap" one by one

This link may help. https://blender.stackexchange.com/questions/103195/smart-uv-unwrap-multiple-objects

Yeah... the question was basically if you can do that without a custom script in the current blender release. But I guess not. Its hard to recommend doing custom scripting to pure artist people, I'll try to package it into a nice command for them I suppose.


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Prevent rotation of the bevel object (Should stay parallel to the XY plane)
How to prevent bevel shape rotation in extrusion operations?
I would like the final shape to remain "parallel" to the XY plane.
At the end of the extrusion (Due to the change of Z along the path) my profile shape has rotated:

Here is my code
def create_rectangular_curve(objname, lenX, lenY):
    # create the Curve and the spline
    ratioY=lenY/lenX
    mycurve = bpy.data.curves.new(objname, type='CURVE')
    mycurve.dimensions = '2D'
    spline = mycurve.splines.new(type='POLY')
    #add points to the spline
    spline.points.add(4)
    spline.points[0].co=(-lenX/2,-lenY/2,0,1)
    spline.points[1].co=(lenX/2,-lenY/2,0,1)
    spline.points[2].co=(lenX/2,lenY/2,0,1)
    spline.points[3].co=(-lenX/2,lenY/2,0,1)
    spline.points[4].co=(-lenX/2,-lenY/2,0,1)
    #create Object
    myobject = bpy.data.objects.new(objname, mycurve)
    bpy.context.scene.collection.objects.link(myobject)
    return myobject

def create_saw_curve(objname, nbPeriode, sizeX, sizeY):
    # create the curve and the spline
    ratioY=sizeY/sizeX
    mycurve = bpy.data.curves.new(objname, type='CURVE')
    mycurve.dimensions = '3D'
    spline = mycurve.splines.new(type='BEZIER')
    #add points to the spline
    spline.bezier_points.add(nbPeriode*4)
    #the first one
    spline.bezier_points[0].co=(0,0,-1)
    spline.bezier_points[0].handle_left =(-1,-ratioY,-1)
    spline.bezier_points[0].handle_right =(1,ratioY,-1)
    #the others points
    for i in range(1, nbPeriode*4,4):
        spline.bezier_points[i].co=(i*sizeX,sizeY,0)
        spline.bezier_points[i].handle_left =(i*sizeX-1,sizeY-ratioY,0)
        spline.bezier_points[i].handle_right =(i*sizeX+1,sizeY-ratioY,0)
        spline.bezier_points[i+1].co=((i+1)*sizeX,0,1)
        spline.bezier_points[i+1].handle_left =((i+1)*sizeX-1,ratioY,1)
        spline.bezier_points[i+1].handle_right =((i+1)*sizeX+1,-ratioY,1)
        spline.bezier_points[i+2].co=((i+2)*sizeX,-sizeY,0)
        spline.bezier_points[i+2].handle_left =((i+2)*sizeX-1,-sizeY+ratioY,0)
        spline.bezier_points[i+2].handle_right =((i+2)*sizeX+1,-sizeY+ratioY,0)
        spline.bezier_points[i+3].co=((i+3)*sizeX,0,-1)
        spline.bezier_points[i+3].handle_left =((i+3)*sizeX-1,-ratioY,-1)
        spline.bezier_points[i+3].handle_right =((i+3)*sizeX+1,ratioY,-1)
    #create Object
    myobject = bpy.data.objects.new(objname, mycurve)
    bpy.context.scene.collection.objects.link(myobject)
    return myobject

profileObject = create_rectangular_curve("profil", 4, 2)
curveObject = create_saw_curve('saw_curve',2,10,20)
curveObject.data.bevel_object = profileObject
curveObject.data.use_fill_caps = True
curveObject.data.bevel_mode = 'OBJECT'

Hello, I 'm sure this a duplicate : use curveObject.data.twist_mode = 'Z_UP'

Thanks Gorious,  it's working, that is what i wanted !! What sould i do to closed the question ?

You can keep the question up, it might help other people :)


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Why Blender and git seems like working so well together?
Blender and git seems like working exceptionally well together!
I took some tests with hundred of megabyte files and versioned these several times.. the result was a git folder of just a couple of MB... and sometime even lighter then before committing!
from test to test I run a git gc for the garbage collection...
I also took some tests on merging and apparently It handles (for simple tasks like materials modification and new objects creation/deletation) the thing pretty well!
so my question is...
how's that git works so well with Blender? Is something in the code? It's because of python... anything else? =]
tested with git 2.17.0-1 and blender 2.79.b-5

Probably because git uses 'zip' to compress files...?

yes but dimensions are almost the same at every commit.. even if compressed, a bin should remain a bin and like so double or like so... the size of the repo!

Blender saves a direct copy of its memory to the blend file. As a result, the file contents change little when you change a small thing in Blender. This allows tools that perform binary diffs (not sure about Git, but Subversion and Mercurial do a good job at this) to produce a small diff.
When you save your blend file compressed, the entire file can change even when in Blender only a single bit was flipped. This prevents efficient diffing, and thus makes it work much less efficient with such tools.


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Vertex Indices change after using Subsurf Modifier
I have an initial mesh with 4 vertices with indices 0,1,2,3 as shown in the first image with index 0 at the bottom left corner.

Now when I use a subsurf modifier and apply the modifier, the indices are changing as shown in the second image:

Now, is there a way in which I can keep the initial indices assigned to the same vertices so that I can access them later on from a script?
PS: I'm using subsurf modifier and not subdivide tool from edit mode because I have objects with more than 4 sides (before subdivision) and hence not able to use subdivide. I'm trying to create a uniform mesh for the object automatically and felt that using subsurf and triangulate and then applying them is giving me a decent mesh. (I know that I can select 4 vertices at a time make 4 sided faces initially and then use subdivide, but I am just thinking of alternate ways of doing this)

Can you post the links of those two questions here?

@R00t Did you ever come across such retaining of indices algorithm after using remesh modifier?

It's interesting how the indices follow a somewhat counterclock wise spiral circular pattern...

Vertex indices are not meant to be used to reference the actual vertex. They are an internal position in a list, not some property of the verte itself. For instance if you apply the bevel modifier, how would you expect the indices to go? All of them have moved.
If you want to access the location of the original vertices, you could store a copy of the mesh. (not necessarily assigned to an object either) If you want to find the new vertices that map to the old ones, the only way I can think of is to iterate through the new objects vertices, find the closest old-mesh vertices, and threshold so only if they are very close does it count them as the same.


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Splitting Object into two different objects using a script
I am splitting an object into two. I am able to do it using the GUI. I go to edit mode, select the vertices I want, then press P and select partition by selection. Can anyone help me with the equivalent in script of pressing P and making the partition by selection. (Not able to find the command in the info window during the operation)
Thanks!

Its bpy.ops.mesh.separate(type='SELECTED').

Hi, thanks for the post. This site is not a regular forum, answers should be substantial, stand on their own, and thoroughly explain the solution and required steps. One liners and short tips rarely make for a good answer. If you can [edit] your post and provide some more details about the procedure and how it works, perhaps add a few images illustrating some steps and final result. See How to write a good answer?, otherwise it may be converted to a comment.

Here is a script I made to split by vertex color. It uses the bpy.ops.mesh.seperate() method as described in another answer. The bulk of it is figuring out what to seperate, but you asked for an example script, so here is one from my toolbox.
'''SPLIT MESH BY VERTEX COLOUR

Script written by sdfgeoff, Jan 2016
Licensed under GPL, share what you make.'''

import bpy
import mathutils

def splitNextColor(obj, threshold=0.01):
    def getPolyColor(p):
        '''Returns the average colour of a face'''
        colors = obj.data.vertex_colors.active.data
        r = g = b = 0
        for i in p.loop_indices:
            c = colors[i].color
            r += c.r
            g += c.g
            b += c.b
        r /= p.loop_total
        g /= p.loop_total
        b /= p.loop_total
        return mathutils.Vector((r, g, b)) #So we can compare colors using the .length operator

    #Pick the first polygon
    p = obj.data.polygons[0]
    target = getPolyColor(p)

    for p in obj.data.polygons:
        source = getPolyColor(p)

        #Select any polygons that are similar in colour
        if (source - target).length < threshold:
            p.select = True
        else:
            p.select = False

    #Seperate the selected faces
    bpy.ops.object.editmode_toggle()
    bpy.ops.mesh.separate(type='SELECTED')
    bpy.ops.object.editmode_toggle()

#Get the current object
obj = bpy.context.active_object

selectList = []
if obj.data.vertex_colors.active == None:
    print("Object does not have vertex colors")
else:
    #Split of colours until there are no face left
    while(len(obj.data.polygons) > 0):
        splitNextColor(obj)

    #Delete the no-polygon object that:
    for ob in bpy.context.selected_objects:
        if ob != obj:
            ob.select = False
            selectList.append(ob)
        else:
            ob.select = True

    bpy.ops.object.delete()

    for ob in selectList:
        ob.select = True


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Check the force values on a vertex
I am running a cloth simulation in Blender. Is there any way in which I can know the values of force acting on a vertex of the cloth or the colliding object?

authors: Евгений Михайлов


text:
Tips and Tricks with using blender with one hand
Long story short, I was recently diagnosed with glioblastoma. I had surgery to remove one of the tumors and because of the surgery, I am paralyzed in my left arm. Hopefully, it's only temporary.
I love Blender as it is my passion, but it has become difficult to use Blender and the computer now with my arm, especially when using shortcuts. I was wondering if anyone has any ideas or tools to make blender more accessible and easier to use with this disability? So that I can make some art again

Would buying a 3d mouse be beyond your means?

Not that I can say it is a solution, but Pitiwazou over on blenderartist.org has a thread concerning his Wazou's RMB Pie menu, and theoretically it could help a lot towards enabling more to one hand.

Thanks everyone for the suggestions, I will definitely be using this to help make some art!

Most operating system have keyboard adjustments for people with a disability. Microsoft Windows has some.  Sometimes on screen keyboards like a modern glass screen cell phone. I do not have the details.
I would guess there are detailed videos on youtube for people with disabilities.
Some ideas below require purchases and time to decide.
Some higher end pointing devices with many keys can be programmed for short cuts.
Second Keyboards are often inexpensive in the second and third markets.
I use an ambidextrous ball mouse often to switch between hands.
I also use a second numeric USB Keypad.
What follows is not a joke.  I have seen on some online retailers selling pointing devices or input devices controlled by feet.  Tailors have foot pedals.
People can even switch hand use with enough practice.

... second keyboard and numeric keypad?

Kinesis offers a triple foot pedal, as well as dual pedal and single pedal versions. (I haven't used it, but I can strongly vouch for the Kinesis Advantage, so I suspect that the pedals are good quality, too.)

I have a condition of the spinal cord, syringomyelia, that necessitates my lying on my side most of the day (I'm paraplegic). So I use Blender one-handed, holding my laptop sideways with the other. I can use either hand, but until last week I could only do Blender with the left hand, lying on my right; on the other side, the shift, ctrl and tab keys are too far away from the working hand.
The solution for me has been a six-button programmable mouse, just 10 dollah on Amazon. I programmed the two thumb buttons to the Shift and Ctrl keys, and now I can at least pan around a mesh without the keyboard. I've never used any gaming tools, but I've seen joysticks with lots of buttons, and if they're programmable, it might work for you. For the rest, I promise you will learn to type one-handed at a decent rate of speed.

I know people who are using some kind of usb pedals so they can do right / left clicks / shortcuts even they have no problem with hands - just to spread the strain to whole body. Maybe you could try find more info about this.
Google something like "usb foot controller".
The easiest solution should be to get a mouse with many buttons and map them to the most frequent shortcuts you use. You can use X-Mouse Button Control program for that purpose.
Or maybe even look at a 3D mouse, but thats much more expensive solution.
Anyway I wish you quick recovery!

Blender is keyboard shortcut based, but there are a few ways to work around this.

The Space Bar menu: it can be used to run most of Blender's operators
Add-ons. There were a few add-ons that I think were made for pen interfaces, such as "3D Navigation" and "Display Tools", that might also help for your situation. I'm not sure if these were included with 2.78, but they came with 2.79 by default. If you're locked to an older version of Blender you might be able to get them to work by copying them into the older Blender's add-ons directory.
The input preferences: In Blender's preferences menu under input you can change most keyboard shortcuts.
As has been mentioned, on-screen-keyboards.

I'm only familiar with Microsoft Windows' On-Screen-Keyboard, but other OS's also have them if I remember correctly. MS Windows actually has 2, one that becomes available in "touch screen" mode and another more advanced one buried in the settings menu:
Settings > Home > Ease of Access > Keyboard > On Screen Keyboard
With the on-screen-keyboard you can enable Modifier keys like CTRL or ALT that will stay active until they're turned off. Enabling the modifier key in the on-screen keyboard has the same affect as holding down the modifier key on a regular keyboard. The advanced on-screen keyboard also a setting in its option menu to add a number pad to the keyboard.

https://www.bforartists.de has an all mouse workflow that you can adapt, with more than 200 keyboard only entries now in the UI, more icons everywhere, and more optimized for mouse only workflow. Might be handy for you.

I have the same problem, and here is how I solved it.  I assume that you are right-handed (and you know that the sticky-keys function does not work with Blender).  Because of the num-pad, you cannot reach the shift and control keys and click the mouse at the same time with one hand.  My solution can be maddening--even for a lefty like me--but you must put the mouse on the left side of the keyboard.  Now you can reach the shift and control keys and click the mouse all with one hand at the same time.  At the very least, the default mouse-button arrangement is perfect for a left-handed person.


text:
How to make a grid of objects with individual rotations?
My goal at the moment is to create a 2D field of a particular object, with each instance rotated a 45° more than the last. An ASCII art illustration of what I want to get, from a top-down view:
| / - \ | / - \ | . . .
/ - \ | / - \ | / . . .
- \ | / - \ | / - . . .
\ | / - \ | / - | . . .
.
.
.

Well, something like that. I'd have to fiddle with the 2D aspect, but it's first dimension I can't seem to get a hold of, just getting what looks like the object spinning as it moves forward. I can't seem to accomplish this in a way that doesn't involve ultimately duplicating each instance by hand.
Here's what I've tried:
I first reach for the array modifier, naturally, but as you can see it doesn't work; the translation of each object is done to the "local axes"(?) of the previous repetition, meaning it'll spin the array in a circle instead of what I want.

So while searching I learned about dupliframes and tried using that. It takes care of the 45° rotation that stumps the array modifier, but then I'd like to use an array modifier to repeat the group of four I have. That modifier doesn't work:

Not too surprising, considering I am animating an array-modified object now, so I guess I'll just "apply" the dupliframes (make them individual objects) and try to link an array modifier between them. But it creates the same issue as above.
At this point I'd have to apply rotations to get it to work, but in doing so I need to un-share the underlying mesh, and then that ends up not being a solution, since it's no better than manual copy-pasting.
Ideally, there'd be a better array modifier that worked on objects rather than meshes, and that would just let me say "Rotate: (0, 0, -45°)  Translate: (0, 2, 0), on global axes" for a total of four objects and have it handle the apparently super tricky task I want to accomplish (then further modifiers would be able to simply repeat the group of four, of course).
However, since as far as I know this ideal modifier doesn't exist, what's the closest approximation to it? Or am I stuck needing to manually duplicate everything?
(Honestly, if I could just tell the array modifier to be based on the global/world axes instead of local ones, this would already be solved.)

The Sverchok Add-on has convenient nodes for this:

You pick the object you want to duplicate, and you pass it a set of Matrices. These Matrices contain location and rotation data each.

The location data comes from the Plane generator (this generates the grid of locations using a subdivided plane with X and Y divisions (W, H).)
The rotation data comes from the Vector (0,0,1)  node and the integer range node produces a steady stream of 25 or (W*H) sequential integer going from [0 .. 18 .. 36 ... etc]

You might set the step size in the list Range int node to 45 or -45, and adjust the W and H to suit you.

The Plane generator generates coordinates (viewing from topview) from bottom left to top right. If you really want to start top left you would transform the output of Plane with a Rotation node.

I think the benefit of this method is that it's entirely dynamic. You can pick whatever number of rows or columns and the step rotation.

Thanks, this is pretty much what I was looking for! I'm surprised that I haven't heard about this addon before :) .

we're kind of laid back regarding general promotion of the add-on. If someone knows what they're looking for, like 'parametric geometry for blender' they'll surely find it.

No addon solution that keeps the objects editable/linked (this is still job for sverchok though):

Add a plane and subdivide 2 times. With the knife tool K cut like this. You can use Ctrl to snap to midpoints:

Inverse selection with CtrlI, delete edges, and extrude in Z axis up:

Set a Dupli group with object of your desire parented to this face array, set to face:

You can copy this piece with Array modifier how many times you want and you can edit your object's geometry.

The simplest solution without no coding would be to array first cubes, rotate them manually and them array once more.

After makng one cube, adding array to it (you can use Relative Offset for this case), you get simple 4 cubes:

Apply the Array modifier and rotate cubes in Edit mode. Add 2 empties as follows (it may be eaiser to tweak their position further on):

Add 2 Array modifiers, set them to Object Offset, select first empty for the first modifier and second - for the second one. Increase Count for both of them.

The rows do not differ, only the columns. Each row should be also rotated from the previous. Your method is thus simply: Rotate by hand.

@Jerryno your're right. I didn't see that somehow. And even taking into account that rows' difference could be achieved by adding Constant offset, this method doesn't provide any flexibility. I wrote this to get only result desired by OP, no further improvement.


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Weird export noise after appending object
I have a planet created in one blender file [A], which I am appending to another blender file [B]. The planet in file A renders beautifuly, while in file B, the render is noisy.
I have checked and can confirm that all Render, Output and View Layer options are set the same in both files. Besides the planet itself, the cameras and lights were also appended, so these should be the same as well.
I am using blender 2.8 & Cycles with both the files, rendering both on GPU. Could anyone give me any hints on what could be causing the difference?

Source files

Is denoising activated in file A (View Layer tab)?

No, it is not, just re-checked and the View Layer tab is configured the same in both files.

We can make so more guesses, but it would probably be better if we could look at the actual two .blend files, if it's possible for you to upload them.

Sure it is :-) Linked in the post above.

I have just also tried doing it the other way around: copying other objects INTO the clean file. Strangely, this also results in the renders from the clear file getting noisy.

The reason for the noise are the other lights and objects in the scene that are placed inside the planet. That's probably not where they are supposed to be because they can't be seen, but they have impact on the rendering and cause more noise. If you move them to another scene or exclude them from rendering it will look just like before. If they are supposed to be placed there and remain visible, you will need to increase the render sample to reduce the noise or you could enable denoising in the view layer.
Disable rendering for problematic objects.

Problematic objects

Before

After

Aaaand - right you are! Many thanks, this never occured to me.