text:
Problem when rendering fire and smoke in Blender Render
I'm having a problem when I render my fire and smoke in blender render.  Here is the problem.  In the first picture it shows what smoke looks like in my regular animation, and the second 2 pictures are what it looks like when I render it.  There is no smoke or fire in the rendered versions.  I am using quick smoke and Blender Render, can somebody tell me why I can't see the fire or smoke in the render? Thanks
Edit:
I am using the Blender Render engine for rendering, and all of the settings for the domain and flow are default other then a few things to get a different look for the smoke, and also the smoke cache has been edited in order to choose at what frame the smoke and fire will appear and disappear.
All objects are available for rendering in the outliner.
I have uploaded 2 more pictures, they are the last 2 (the last 2 pictures in the list, not the last 2 forever.. :) ).  The second last shows what the smoke looks like in the viewport, and the last is what the render looks like.  As you can see there are particles coming out of his mouth (the grey object in his mouth is the sphere used as the flow) but they are very faint and almost invisible.  They are there, though.  The flow object I have inside the cigarette is very tiny, and I believe that is why I cannot see the flame in the render.  So how can I alter the render so that the flames are more prominent? Or perhaps make the flames themselves more prominent, along with the smoke?
I have tried changing density and other settings but they seem to make no difference once I render the image, and the renders turn out basically the exact same as in the pictures I have posted below.
The goal of this was to make an animation of somebody smoking a cigarette, where I have shape keys to allow the cigarette to get smaller, while at the same time I have shape keys moving the domain and flow of the smoke and fire with the cigarette's shrinking (to give the illusion of a cigarette burning and getting smaller).  The character shortly after leans back and breathes out, where I have a smoke domain and flow object move into his mouth (again from shape keys, the object is originally under the ground until it moves in 1 frame to his mouth, and then after the smoke has been given off it moves back into the ground).  The smoke is propelled by a wind force field, which is how it moves horizontally to give the illusion of smoke being puffed out.
I don't know if this is the proper way of doing it, but it is what I came up with and seems to work other then the rendering.  If you know of another way of doing this without changing to much, I would love to hear it.
Update: I have tried rendering an image without both domains in it, and the smoke still looks the same, so I do not believe it is the problem of having 2 domains in one scene.  From what I've read, that only becomes a problem if the 2 domains overlap, and in my case they do not.
Here is the .blend file, so we can cut to the chase here:
https://drive.google.com/open?id=0B3lBHOw4Hc3tWmVPYlJscFNydjA

Here is the link to my Flow and Domain settings:

https://i.sstatic.net/CLhzI.jpg
Please don't hesitate to ask for more information. Thanks

Sorry, I'm new to this forum, but I don't think I can post anymore links without having a reputation of at least 10.  How shall I post more pictures?

I have added the links to the post.

Thanks for the advice, I have added much more information about my problem.  My apologies for the double post.


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B-Bone not displaying as box but instead displaying as sticks
I'm having a bit of difficulty with armature displays.
I've selected B-Bone as the display which I know is supposed to make bones look like boxes but instead they're appearing very thin like the stick display. I thought it was because I somehow accidentally re-sized the thickness of the bones so I tried tampering with it with ctrl + alt + s and such but that didn't seem to work. Here's an image of how it looks.

If I could get any sort of help that would be great! Thank you all in advance.
[edit]
here's the .blend file

ctrl alt S works, it's just that your bones are very very thin, so scale several times.

looks like the bones were extremely thin that I had to scale it a bunch of times for them to look thicker. this solved my problem thank you!

If you have scaled them down to absolutely zero you will see just a simple line and there is no way to get back and you should redo everything from the beginning.

source: Stack Exchange

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

sort: votes


text:
How can I achieve a Japanese style cell animation toon shader look in Blender?
Here are my examples.
Edit// Here is a video showing what I want exactly, how "shaders" and "renderer" should work.
https://www.youtube.com/watch?v=XQLgn9-xqQc
notice how easy it is to set the shadows on the character in the video here?

Somehow they have controls over the shading, and normals. And the shader draws smooth lines around the edges. Here are more examples.

Animation:
https://twitter.com/twitter/statuses/916984184035360768
This here is actually created in blender.
https://orig00.deviantart.net/f78a/f/2015/056/9/e/untitled_by_keiichiisozaki-d8jfztd.gif
I actually think it's better than most of the other ones, I don't know what tricks he used, or if it holds up in full 3D animation though.
The others are all pretty much 3DS MAX Pencil+ plugin.
here's some more examples even.
I would like to know, what kind of settings, what kind of stuff I should be looking for, to copy this style with blender, or if anybody pro enough to create a short tutorial it would be amazing!
Here are a few more. Supposedly, this style is "easy" if you have the 500$ 3DS Max plugin...
Anybody know here?
https://entry.cgworld.jp/column/toei_main1.jpg

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


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My image won't render. Every time i go to render, all I got is a grey screen
I have tried many methods and none of them worked! I tried blender render and cycles render, checked that everything was able to render, and i even tried re-doing the project all over! Anyone have anyway i can fix this? Ill add the blend file.
http://www.mediafire.com/file/3gdy6rf3zg6xvkg/thing.blend  (File was to big for other options, so mediafire I guess)

Please add the .blend using http://blend-exchange.giantcowfilms.com/ Also, adding some screen grabs to your original post using the "edit" botton and the "phpto" icon in the edit bar.

Ok, I added a blend file and some screenshots. I hope it helps

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


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Which Version of IFC Open Shell do I download
I am trying to import IFC architectural files to edit and render on blender. I read that I have to add IFC Open Shell but when I try do that it says determine if my copy of Blender is 32 or 64 bit. How do I find tht out?

Help > Save System Info in Blender and save the file to your desktop. Then open the file in a text editor and around line 15 you'll see: "build linkflags: /MACHINE:X64" (or X32 if 32-bit). However, I don't think the later versions of Blender are available in 32-bit nowadays so it's almost certainly 64-bit anyway.

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


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How can make more yellow point for sculpting

I am a newbie to Blender. I try to make the figure of the body.
I follow all instruction from this video youtube tutorial.
(slow down 0.25 to follow).After finish basic figure turn to the part of sculpting. I am only have four points for grab. The video have more points for grab.
How is it possible to start with a normal cube that has more points like the ico sphere ?
What wrong of my setting?

you can go in Edit mode, select all and right click > Subdivide. Then in the Operator box (bottom left of your 3D view) increase the cut number and put the Smooth value at 1

I have to disagree. It's the Subdivision modifier that you need to apply. If you additionally subdivide the cube manually you will end up with a bazillion of vertices. More than you will ever need (=bad performance). Of course, you can remove the modifier and subdivide it manually. That's ok. But not both.

You need to apply the Subdivision Surface modifiers of the cubes before you can sculpt the high poly mesh.
Go to the Modifiers tab (right side of screenhot 2 below), open the drop-down menu right next to the modifier's name (Subdivison) and choose Apply -or- hover the mouse over the modifier and press Ctrl+A.
The modifier takes the base mesh (the cube), subdivides the mesh, and outputs a sphere-like mesh that you see. In Sculpt and Edit mode you can only modify the base mesh (the cube).
Turn on the Wireframe in the Overlays menu:

... and switch to Edit mode:

Here you see the base mesh that you can edit and sculpt, and the output of the modifier at the same time. The crosses of the black wireframe indicate the points where you can grab a yellow point in Sculpt mode.

After you have applied the modifier you will have a lot more points to work with.


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Is there a way to update Blender without deleting it and downloading the new version?
I like to stay up with the latest version of Blender. I use Blender on my Macbook Pro and it is kind of a pain to update Blender because you have to delete it and then re-download it.
This isn't a huge deal but is there a way that you can just update Blender without deleting it and re-downloading it every time? It is kind of ridiculous to just re-download the entire program when the new version consists solely of bug patches.

Ridiculous?, for bug fixes? I would think not. ;)

Blender doesn't have an (auto-)update function that would do this for you.
Some years ago I experimented with a way to create binary patches - that works pretty ok, but the experiment never took further form, as an entire infrastructure to support this needs to be created, and for such an effort no resources have been found (people willing to work on it, maintain it and the servers).
Until that day you'll just have to download the entire program. Note that you don't have to install Blender, you can just run it from the location you downloaded and extracted it to (at least on Linux and Windows, so assuming it works also on OS X).

Yes, also on OS X, extracting and dragging to the Applications folder works fine. :)

That isn't possible with the binaries. However, you could do that with the source code.
You could download the source code from the repository and compile it by yourself. With this method, you only need to download the files that changed. If you choose to do this, you will need to compile Blender each time you update your code which is more time consuming than just installing it.

@PhoneixS Why binaries can't be updated?

@iamcreasy Normally when you think in updating a binary what you do is replace the binary, not change it only what have changed because in binary a minor change could be all bytes modified. Instead in source code you normally can break it in lines, so you only need to update lines that have been changed. Although, you can still have binary parches if changes are little, this are very used in applications crack. I have tried to answer you, but I think that my answer isn't so clear :D

@PhoneixS Yeh I got it. But why they don't have a system that updated the binaries...Many closed source software do it. right?

@iamcreasy, I think that principally because they don't have enough time and resources to do it.

Which is faster depends entirely on the speed of your pc and internet. I have a fast pc but snail-paced net, so compiling takes a couple minutes where downloading a new build often takes over an hour.

I heared that you can install Blender via Steam and it should be updated automagically.

Yep... https://steamcommunity.com/app/365670/discussions/0/618460171315633543/#c618460171315922595, https://www.quora.com/Whats-the-best-way-to-update-Blender/answer/Francisco-Mateus-2, http://www.leadwerks.com/werkspace/topic/12513-blender-now-available-on-steam/#entry90245, http://www.blendernation.com/2015/04/25/blender-is-now-available-on-steam/

Related: http://blender.stackexchange.com/q/39296/2843

If your on Ubuntu (or some linux distro with automatic updates, basically all of them), you can choose to download the latest development build. You'll get the updates then. If your interested, here's a link: http://mbah.net/2010/11/11/installing-blender-2-55-beta/

Broken link.  :(

If your OK with using the buildbot dailies, you can use BlenderUpdater application:
https://github.com/tobkum/BlenderUpdater

You can install Blender via Steam, which has a built in auto-update feature.
This should keep your Blender installation up to date automatically.

https://github.com/overmindstudios/BlenderUpdater/releases/tag/1.9.2?fbclid=IwAR3D3TPfIJ4xhP2W0z_0Kg-FO3Z3_d3IAHLFTsdF1Bc3yHAnx_NeT8iYLU4
After googling for a while, found this blender updater program.
Works for me!


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Animation within a game using property
I am trying to insert an animation controlled by keyboard within a game, but property seems not working properly.
I am using blender 2.74
Steps I do:
Create an animation (keyframes) for the camera.
 Create the game logic with game logic editor:

Create a property
Add Keyboard sensor AND Property actuator
Add Always sensor AND Action
I have done lot of test without success.
If I have only the Keyboard sensor, I see (debugging) the property changing, but when I add the Always, the property acts weird. Sometimes it get back to 0 every time I press the key, sometimes changes more or less  normal till appear strange numbers. [In neither of the cases the animation runs]
In other way the same, if I use only the action, it works correctly. [Animation runs].
I have also try to use the Property sensor (plus the Keyboard sensor), but again, not success.
I was trying to follow https://www.youtube.com/watch?v=vU1fMYqoJ8I tutorial, but it is done with older blender version.
Any help?
Many thanks!

may you take a screenshot of your "action" actuator? problems usually result there.

Hi Radish, I finally fix the issue. Instead of using always for the Atcion, I need to use the same Keyboard Sensor.

I finally fix the issue. Instead of using "Always" for the Atcion, I need to use the same Keyboard Sensor.

Thanks!!


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Set pivot point of empty object
I've got an empty object which is parent to a couple of meshes. I want to keep these meshes seperated in order to be able to adjust their materials individually, but I want to rotate them altogether. That's why I created the empty object and set it to be the parent to those meshes. I am able to rotate them together, but the pivot point is (0,0,0).
If I try to set the origin of the empty object via Ctrl + Shift + Alt + C it doesn't change anything. I can change the origin of all the meshes to the desired pivot point, but still can't rotate them via the empty object. Any suggestions on how to achieve that? Thanks in advance!

Why not using Copy Rotation constraint  ? As another way, you might want to change Pivot Point, Shift+S to snap cursor to your empty, select desired objects and rotate them around themselves or around 3D Cursor

Rotating the empty around the 3D cursor which has been snapped tot he desired location should work perfectly.

An empty object does not have an origin, but it does have a Location.  You can use the G key to move it, or just type new values for the location into the Properties panel.
Unfortunately, this will cause the child objects to move with the parent.  You can use the Shift+G menu to select the children and move them back to their previous world position with G.
For example: On the parent object  G, Z, 3, Enter. G, Y, -, 2, Enter. Then select the children and G, Z, -, 3, Enter. G, Y, 2, Enter to move them back.
Alternatively, you could clear the parenting relationship with Alt+P; move the empty; and then re-parent.
Once you have the empty in its new location, rotating the empty will cause the children to rotate around that empty's location as the rotation center.

I was using Empty >> Image and stumbled upon this problem but I solved it in a moment. When you add an empty, (here I added the logo just for visibility) go to Data and you should see the Offset. Set both the values of X and Y to -0.5 and it should be in the center. You can then go ahead rotating as if it were a Plane. Hope this helps!

To elaborate on this good solution: Open the empty Object Data Properties tab, use Offset X/Y values to move the image while the center remains fixed. Set the desired pixel under the center of the empty.  Reposition the empty so that the image is moved back at its desired location. Sorry for providing a long list of action descriptions rather than a long list of meaningless key press directives :-)

I found the best answer elsewhere and am sharing it here:
Select the empty, and then hit Shift+S > Selection to Cursor

The most straightforward solution today would be to check "Affect only parents" in the 3DView sidebar, under the "Tool" tab, in the "options" panel. This allows transforming individual elements in an object hierarchy (such as the parent empty here) without affecting their children.


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geometry nodes and object instances not applying well to curved mesh
I'm having difficulty correctly applying object instances to a curved mesh object. You can see here from my image below that the instances are not curving with the curved mesh. I'd love some direction on how to do apply a flat object instance to a curved mesh and have it curved along the curved mesh face using geometry nodes. I have searched high and low on the interwebs and cannot seem to find an answer.

geometry nodes setup:
https://i.sstatic.net/eVF26.png
more example images:
https://i.sstatic.net/tjWbB.jpg
Thanks!

here's a setup that could work for you... the plane you want to instantiate needs to have some resolution, just 4 vertices will not bend / adapt to mesh... and then you need to realize these instances to be able to move each vertex... a raycast node will search for best point on the surface to snap your vertices to
I used an icosphere to instantiate the planes -just a few- but then subdivided it to have a better surface for snapping... may need to flip the normals on the plane or the ray direction in raycast node... also remember that the grid or the sphere could even be GN primitives

That's fabulous!

thanks @NatureK you had a nice setup too, I saw later it was your answer linked here

No,I don't get the right answer,I just align the normal,but don't achieve the shrink.

Thanks! Is there a way to preserve the object that has the geometry node modifier? this seems to either remove its mesh or replace it with the object instances.

sure, use a 'join geometry' node next to the end and connect your 'group input' geometry... or place GN modifier on some other mesh and use 'info node' to input the sphere


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Cycles: out of SVM stack space, shader "" too big
Any idea on how to increase this? Im working with a rather large node tree and adding #noise.random() as an input value looks like the straw that broke the camels back. I'm able to get it to work if I switch cycles device to CPU with OSL enabled but that will take soooo much longer to render this.

are you mixing diffuse shaders? One way to to keep the stack space a bit lower (and to make it render faster too), is to not mix the diffuse shaders, but to mix the colors that you plug into the diffuse shader.

@HarryMcKenzie would a diffuse shader be a MixRGB?

MixRGB node and Diffuse Shader node are different nodes.


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How can I speed up this bake script I wrote?
I wrote a script that handles baking objects textures into an image node that is then attached back to a bsdf node. It works well for the most part. It's just really slow. Like 45 seconds - 90 seconds for the baking process. I'm wondering if there is a way to optimize the script I wrote, or is this just as good as it gets? The problem I'm trying to solve here is that I have a collection of objects that I need to iterate through and bake each one. The actually project this is for has hundreds of sub-collections and objects. At its current output speed for each object, it will take days or even a week to bake all the objects lol.

Any advice or feedback is super appreciated! Thanks

https://devtalk.blender.org/t/why-is-texture-baking-so-mind-meltingly-slow/5653
This post actually solved my problem. I was focused on the script being the issue, where the slow render was a result of the sample count of my render. I reduced it to 16, and it has dramatically reduced the bake time.


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Need help with script that loops through a collection and bakes objects
So I'm having some difficulty with a script I wrote that should loop through a collection of objects and bake the materials for each object. I feel like I'm pretty close, but the script is failing at the bake method.
ex of the data structure:
parent: {
  child1: {
    obj1: {},
    obj2: {}
  },
  child2: {
    obj1: {},
    obj2: {}
  },
}

obj ex of whats being passed into bake:
<bpy_struct, Object("Variant 1") at 0x000001711493E408>

script
variants = bpy.data.collections["Variants"]

def bake(obj):
    print(obj)
    bpy.context.view_layer.objects.active = obj
    image_name = bpy.context.active_object.name + '_BakedTexture'
    image = bpy.data.images.new(image_name,2048,2048)
    nodes = bpy.context.active_object.active_material.node_tree.nodes
    links = bpy.context.active_object.active_material.node_tree.links
    bsdf = nodes.get('default_egg_bsdf')
    texture_node = nodes.new('ShaderNodeTexImage')
    print("1")

    texture_node.select = True
    nodes.active = texture_node
    texture_node.image = image #Assign the image to the node
    print("2")

    bpy.context.view_layer.objects.active = bpy.context.active_object
    bpy.ops.object.bake(type="DIFFUSE")
    print("3")

    links.new(texture_node.outputs[0], bsdf.inputs[0])
    print("4")

def bakeVariants(coll):
    for obj in coll:
        obj = obj.all_objects[1]
        bake(obj)

bakeVariants(variants.children)

the error is "Error: No valid selected objects.", I've tried a couple of different methods to set the object being passed in as selected, but none have been working as expected.
If someone could maybe try this script out or provide some feedback on my implementation, I would really appreciate it!

I see where you set the view layer active object but I don't see where you set the bpy.context.active_object. I would guess that's why the bake fails?

to Marty Fouts point, I was not setting the bpy.context.active_object. This was the solution for blender 2.8+ bpy.data.objects[name].select_set(True). I added this to line 3 of my bake script, which resulted in my expected output.


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Best Practice for clothing items (zip) to attach to clothing (jacket) with cloth simulation
The objective is to create a realistic jacket which has zipped pockets on each side, but for it to work with cloth physics enabled.
The problem is to find the best solution for having a separate object, such as a zip, work with the simulation.
What would be the best practice for this, or is it simply best to cheat it?
What I've tried so far:

Create the zip as a separate mesh
Create an empty and vertex parent it to the pocket.
Parent the zip to the empty, so the zip
follows the jacket during simulation.
Use weight paint and 'pinning' to reduce amount of
bending/deformation around the pockets.
Use shrinkwrap to 'attach' the zips to the
pocket and to deform with jacket during simulation.

The problem, is that the shrinkwrap still deforms / stretches the mesh with unwanted results -

Blend file (updated):

i don't know, never tried, but imho the zip should deform at least along the line, to be realistic... thay are not undeformable objects, they usually follow the tissue the're bound to, although a bit more stiffly...

Granted, it should deform slightly. But to be more specific, it's the zipper's teeth that shouldn't which is the result I'm getting.

probably having at least a partial file to see your setup, and try in some way... if you can, upload to http://blend-exchange.giantcowfilms.com/ (permanent storage)

I've now uploaded the test file, thanks @m.ardito

The blend file you uploaded doesn't quite match what is shown in your image. Let me know exactly what you need to achieve and I'll see if I can create my own setup. You need to specify:1. is it going to be used in animations? 2.Will the jacket eventually goes onto some character's body? If not, where do you need it? 3. Do you need to animate the zipping-unzipping?

Thanks @SVAFnemesis. Please try to download the blend file again. In answer to your questions: 1) Yes 2) Yes, on a realistic human mesh, however I had to remove the model so that it didn't exceed the file size limit, instead I've replaced it with a low-poly mesh. If you would prefer with the original mesh, I can upload the file to my server. 3)No, just as is, animating with the cloth simulation.


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Need help with animating textures using AnimAll (texture moving is somehow visible during animation)
I'm trying to animate eye blinking with help from this tutorial:
Animating eye texture in a head mesh
and while doing everything the tut mentions, the outcome somehow doesn't look good. The problem is that the texture moving is visible in animation, as shown on this screen:

Anyone knows how to solve this? D:


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Why can't I animate my characther's face while the rest of the body is moving?
I know how to use the timeline; I can set keyframes and have characters move; but when I try to make keyframes with anything face-related, if I move/rotate/scale it in the second keyframe, that is the position/rotation/scale it has for the whole animation. I can edit the face, but I can't make it change during the animation. This means no blinking, no talking, no looking around... it's really annoying.
Does anyone know what could be causing this?
https://www.dropbox.com/s/lg0sf5cpsdbswg5/SomeIdiotsProblem.zip?dl=0

Post you .blend so it's easier to debug this. It seems like your rig is just broken

It isn't my own rig I'm using, and it happens with every rig I try, not just one.

Ok... Did you animate the face after the rest of the body? When you keyframed the body did you do it with everything selected?

I did animate the face after the body. And I didn't animate the body parts with everything selected.

Still, post your .blend

Ok, I posted it.


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Making a single node using multiple nodes
Is there a way to reduce a set of nodes to a single customized node. I am needing to put some mathematical expression and when I do it using the node editor (in animation node) the whole tree looks quite clumsy and it becomes quite unreadable.

Select desired nodes and press Ctrl+G

https://docs.blender.org/manual/en/dev/compositing/types/groups.html ?

This is quite simple. All you have to do is to create a group from the nodes.
Simple example:
Say you have some fancy node setup:

To group these nodes, select those you want to group (press B to border select ). Then in the nodes menu select Node > Make Group (or press Ctrl+G):

After having created the group, connect the input sockets you want to have as input (here the color to diffuse shader):

To get out of your group click on the little up arrow at the bottom:

(Or press the Tab key)
Et voilà, you have a fancy shader:

Hope that helps

I am able to get the option of make group for materials node editor but not able to get it for the animation node editor.

I have added the relevant image


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Feeding the 'shape key' value from a variable in python script
For the sake of mathematical accuracy i need the shape key to change as i change a variable declared in python. I know how to declare a variable in python. Now how do i use that value to determine my shape key values.
This actually can be a general question:- how do I use a value of a variable declared in python terminal at any other place in the GUI editor. Eg- declare a vector of numbers in python and set the z position of an object to change accordingly at every frame. I have a feeling that it is easily possible through scripting(though i have not tried it) but is there any graphical way of setting this condition?

Drivers and shape-keys

could you please explain some more, I could not follow or understand what that post meant.


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Scripting alternative to editing colour based on vertex coordinates using Nodes editor
I am trying to add colour to a mesh object where the colour varies based on the z location of each vertex (similar to a heat map). I am able to do so using the nodes editor (cycles render)

into

using the following nodes.

Could someone please tell me how to achieve the same (or similar) result using scripting in a very simple way?
I have currently made this mesh in the following ways.
import bpy
from math import *

ob=bpy.data.objects['Grid']
for v in ob.data.vertices:
    v.co.z=-0.2*(((v.co.x)**2)-((v.co.y)**2))

I was hoping for a similar way to edit the colour of the mesh, where I select the vertices individually and then assign a colour to it based on the z location of the vertices. I am just not able to find the right python command to edit the vertex colour.

Does this answer your question? Control Cycles material nodes and material properties in Python

Hi. Do you mean you would like to have a script which can generate those nodes or a script that can colour the mesh without the nodes?

@RayMairlot  I don't want to generate the corresponding nodes using python. I was hoping to be able to avoid nodes altogether, create the material in a simpler way, similar to the way I have made the mesh (code included in the edit).

@brockmann I was hoping to avoid the nodes editor. Is it possible to edit the colour directly from the script? similar to how we can assign a material directly from the script with the command    bpy.data.materials["Material.003"].diffuse_color=[1, 0, 0]

Have a look into vertex colors: https://blender.stackexchange.com/a/911

Texture space
For this case I think node material is the easiest way to go.  Added a link to bottom that similarly to @IsawU's answer (or at least I think so) writes a value to a UV map

AFAIK the generated texture space box around an object maps 0 to 1. ) Object Properties > Viewport Display > Texture Space We can plug this straight into a colorramp

After arbitrary resize and change yellow to blue

With vertex colours
Displacement generated in grid using question code. Vertex color layer named "Color" added and set on vertices to go from red (low) to blue (high) locally.

import bpy

context = bpy.context
ob = context.object
me = ob.data

for v in me.vertices:
    x, y = v.co.xy
    v.co.z = -0.2 * (x * x - y * y)

vc = me.vertex_colors.get("Color") or me.vertex_colors.new(name="Color")

z = [v.co.z for v in me.vertices]
zmin, zmax = min(z), max(z)
r = zmax - zmin
if r > 1e-5:
    cols = [((1 - (v.co.z - zmin)/ r), 0, ((v.co.z - zmin)/ r), 1) for v in me.vertices]
else:
    cols = ((1, 0, 0, 1),) * len(me.vertices)

for l in me.loops:
    vc.data[l.index].color = cols[l.vertex_index]
me.update()

Result

Related
https://blender.stackexchange.com/a/161678/15543
Applying per-vertex colors to new Bmesh
set a specified vertex color to black via python
Setting per-vertex colors
How to get random color variation on a single mesh?

I was searching for a solution similar to the second method that you have provided. I tried it and it worked exactly as I needed it to.  Thank you.

I have devised a way to do this kind of hassle free.
I include my .
To set up your scene like me, you need:

a plane with 1 subdivision per 1 meter centered around world origin
(limitations of math used)
a material 'Material.001' with Image Texture as the source for color

When you hit run script you should see

The function runs from -32 to +32 on the X and Y axes to make the script a bit easier thanks to vertices with integer X and Y coordinates, but we would typically require a finer grid around 0 and so I use (kind of improperly named) zScale when displacing the vertices
v.co.z = -0.2 * (((v.co.x * zScale) ** 2) - ((v.co.y * zScale) ** 2))

Feel free to adjust zScale to quickly preview how the script behaves when the Z extremities are more extreme.
How does it work

displace the vertices
get the min and max Z coordinates for coloring purposes (in separate for loop for clarity, could be done in one loop)
create a square image with the same amount of pixels, as there are vertices
loop over vertices and color pixels at XY coords matching the XY coords of vertex (that's why they are integer) based on the Z coordinate, utilizing the min and max Z coordinates to go from green to red
assign the texture

Edits I leave up to you

allow non-integer XY coordinates
you might want a fixed color scale, not an automatically adjusting as in my file
rotate the image (might be necessary for non-symmetrical functions, have not checked) seems to work correctly as is
always rewrite a single image file to reduce the clutter
add a script to set up the scene automatically for a drop-in capability
fixed resolution image for high density meshes (for speed reasons)

Alternative
The commented out section at the end of the code
I was playing with an idea to use the depth buffer to color the graph.

Set up an ortographic camera above the graph, looking down at it
render
use Viewer node to use the depth buffer in script
create image same size as the depth map
loop over pixels in depth map, assign colors to the new image based on that

Works even if you displace the vertices on the Z axis by hand.
References
The how does it work section should allow for the code to be reconstructed at any time, I will drop here some answers for reference:

creating and modifying images
editing material nodes
accessing 'Render Result' through the Viewer node

I have just noticed, you use pre 2.8 Blender. If you can't switch to 2.8 and later, you should still be able to use this as a reference.

All this said, generating the node setup by code should be easier, yield faster results and work even if you displace the vertices by hand.

I tried ur blender file and it seems to be working fine for me currently. But I will have difficulties in future when I need to colour an arbitrarily shaped mesh (instead of a square of a rectangular grid whose vertices are located at integral x and y) and also, instead of just the colour, will I be able to use this method to edit other material properties like emission, transparency, etc...  And I have now downloaded blender 2.82.

Yes, you should be able to use this method to change emission, transparency, etc. (You will need to add other textures to the node setup for these) If your mesh is going to be a square grid, or even rectangle grid, you should be able to do it with more math (for the non-integer coordiantes), other than that you could try affecting the UVs of the vertices, but that might get pretty difficult very soon.


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STL file quality decreases
The stl file that I export the quality seems to lower, it goes from a higher quality to a lower quality. Any help on how to export at full quality?

There are no "quality" settings when exporting 3D models for the most part, polygons are exported as-is, non are removed or added without explicit user intervention. Could you clarify what you mean?

The STL has a lot less Polygons compared to the original model was 46mb whereas the STL is only 14.6mb, so the quality seems to have decreased.

I have added a second image to show the difference.

Looks about the same to me. One is smooth shaded the other is not.

Smoothing messes up the model, there are a lot less polygons on the stl then the original blender model.

Make sure all modifiers are applied before export. Generally there is Apply Modiifiers option in STL export but first it has to be enabled and second it isn't necessarily applying modifiers with those options which you see in viewport

How do you get the Apply modifiers settings I can't find it.

see https://docs.blender.org/manual/en/dev/modeling/modifiers/introduction.html#the-modifier-stack


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Boolean acting strange

I cannot find anything regarding the problem im having with blender..I only been using it for 3 weeks.
I open up blender and then shift-A to add another cube. I then go into edit mode and press bar to search for boolean. When I click on boolen to apply to my new cube, (or any new object) it disappears.
Any ideas please?

Can you explain what you are trying to achieve/expecting to happen by doing this?

It seems like you misunderstood, what boolean operations are. The Manual also provides useful examples on the boolean modifier page.

Thanks for replies, I added another picture of what I use actually trying to do..Practicing using boolean to cut out part of an object. Wasnt trying to join or anything like that

You're messing up Edit mode Boolean and Object mode Boolean. Edit mode has its own Boolean (not modifier) as of new Blender versions, maybe 2.77. As you're in Edit mode for the object which is nothing other than cube there isn't anything to intersect and quite obviously it disappears after intersecting with null.

First of all:
I assume, the feature you are looking for is Join (Ctrl+J). Therefore you have to be in objectmode.
But as mentioned in the comments of your post,
booleans only give results with intersecting Objects.
Also, the "Intersect(Boolean)" tool only works if both meshes you want to perform the boolean with are in the same Object. This tool performs a boolean operation with the Selected and unselected parts of your object.

To perform a bool between two seperate objects you have to use the boolean modifier or addons like booltool (which are basically also using the boolean modifier)

Thanks for replies, I added another picture of what I use actually trying to do..Practicing using boolean to cut out part of an object. Wasnt trying to join or anything like that.. Guess i got to just keep at it :)

You are using the wrong tool. the Intersect(Boolean) works only in edit mode. I also explained this in my answer ;-)


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Z Combining a blurred/glared render layer
I have 2 render layers, one with the main object and one with a particle field (volume). If merged, the main object would be somewhere in the middle of the particle field. This means that some particles are in front of the main object and some are behind it.
Now I'd like to do some glare and blurring on the particles and then Z combine them with the main render layer. However, glare is not visible for some reason. If I disable "Use Alpha" on the Z Combine node, not even blur appears to be working.
Current node setup and result, neither of the glare nodes has any effect on the composite:

With "Use Alpha" turned off:

Could I achieve the same by using one render layer and object ID masks?

Check here: https://blender.stackexchange.com/questions/88613/problem-with-id-mask-and-glow-effect/88662#88662

Glare adds glare and removes transparency. Instead of AlphaOver node after Glare in your setup use MixRGB node set to Add to add glareto your setup (which is what glare and light does), then areas with glare present will be added on top of the image and black areas after Glare will just add nothing (something + 0)

@Mr Zak The problem is lack of glare on particles, not so much on the main object

@MrZak That alpha > Z connection slipped my checks, whoops. Fixed the post, the problem is still present.


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Color management for EEVEE animation
I am rendering an animation in blender 3.1 using EEVEE. The colors of the rendered animation look totally different then the ones in the preview.
If I render a single frame then colors are right. How can I sort it out?

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.

Previews can vary from rendered animation mainly because of lighting differences.  So the first check is to make sure that the world lighting you're using is the same between the two and then see if there are any lights enabled in preview that aren't enabled in render.  EEVEE cuts corners with lighting so the next checks are to see if your material and lighting settings are different between preview and render where they can be.  Beyond that, maybe show us a screen grab of the viewport preview and one frame from the animation where it's different.


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How can you cut shapes out of an object with other objects?
I know this has been asked before but I seem to be struggling to use either the knife project tool or merging meshes and then separating out sections to cut pieces in a mesh. This is probably due to some fundamental misunderstanding but there must be an easier way to do this rather than making 1000 edge loops to line up with the curves.

Here's the sheet with pieces overlayed:

When I consolidate Ctrl + J then separate P you can see that the piece gets separated but the original base sheet remains untouched.
If anyone has any advice that would be much appreciated. I was hoping the knife project tool would be the easier way but whenever I use it only part of the piece gets cut not the entire thing.

https://blender.stackexchange.com/questions/50538/how-to-cut-an-object-along-a-curve https://blender.stackexchange.com/questions/77279/projection-geometry-example

Unfortunately no dice, the extrude through the object and intersect method is the closest but the curved section doesn't get added to the base sheet so it ends up missing!

Aha so I think an issue with that particular piece is that the curved vertices aren't connected through the base sheet. However when I try to connect them by selecting then pressing F either only the top and bottom points connect or they don't line up with each other. Is there an easy way to connect the vertices without having to select them all one by one?

The way I would usually do this is to make the cutting objects 3D and then join them with the object to be cut then use Intersect (Boolean) face tool.

I like this approach and it seems the easiest but unfortunately the curved section on the piece shown above is not connected across vertices and for some reason the base sheet then doesn't recognize the curve even if stretched through the sheet, I guess because there aren't any edges along there that are intersecting so I'd love to know if there's an easier way to connect those vertices rather than selecting each one by one?

@KaphaSound Can you share your .blend file? https://blend-exchange.giantcowfilms.com


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Vertices seem to be stuck when sculpting
I'm working on a model, and I can move vertices in edit mode just fine but once I go into sculpting there are certain vertices that refuse to budge the way they should.
This is how it looks unedited.

But then as soon as I go into sculpt mode and try to drag it, stuff like this happens.

I tried recalculating the normals because that seems to be the obvious solution but it didn't change anything.


text:
Diamond Renders
I currently have a diamond stud earring on a character I am making. My current render scene has a very typical 3 point (with some additional lights here and there to ease shadows) setup. It's a direct facing portrait shot.
At the moment my diamond isn't really.... glimmering / looking white and sparkly (for lack of better terms)... Do any of you have a clever way of cheating this? I am aware that a diamond is only as good as it's envi / things to reflect... hence why I was wondering? Was considering maybe using an HDRI on low strength or something but figured I would ask here first to see if you guys have already solved this problem
Final render will be in Cycles

Hi :). Yes, a high-contrast HDRI is exactly what you need

There's also a tutorial on procedural crystal materials here which might help.

Thank you for the replies I will look into this tutorial and fiddle with some HDRIs


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Cigarette Emissive Lighting
I’m trying to make a bit of an ominous render in which my character has a cigarette in his mouth and I want his face to be lit by that and the rest of the scene dark.
I’m using this model as a place holder for a proof of concept   https://sketchfab.com/3d-models/cigarette-daily3d-eff40b1550e0466a9c3273a519139143
Any clues as to how I can achieve this? I’m using cycles at the moment with an emissive shader node but…. Not great. Wondering if I need to add some fog or something.
Just curious if either of you have rendered something like this in your past

This cigarette model that you linked is over 1800 meters long. Yeah, over a mile! Be careful when you import it  --A while ago I did something similar to what you described. So I composed a scene to see what this would look like. Well,  you can always add an extra light if the emission shader is not strong enough and use the compositor for post-render effects. Without smoke, there seems to be something missing. I would definitely add it.

Hahah yeah it’s quite the cigarette that’s for sure! Ok I will add some smoke hopefully that helps it a bit and maybe some really dim lighting

Maybe post a screenshot and describe what you don't like?


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Generate rig ruins my animations
So I was making my first animations with blender and after I was done I hit generate rig and the rig doesn't have any of the animation data applied to it. The metarig has all of it and if I parent my character to the rig it warps my character in extremely weird ways. Any ideas whats going on??

If you are working with rigifiy or something like that, you need to know, that metarig is used only for setup, not for animation. I suppose you should remove all transforms from metarig before generation

I will try this. So then the generated rig is what I use to make the animations? I was using the metarig and moving the joints of the bones and adding keyframes.

Metarig is not designed for animation, It is used for locating bones and joints in generated rig

Okay thank you im redoing my metarig then going to try again, this makes sense because the tutorial i was watching somehow had a generated rig without ever showing when he made it. So I assumed he made it after doing the animations not before. Guess I was wrong

So I tried it again and just like before when I press generate rig the legs turn into spirals. Like as if I was ringing out a cloth thats what my legs are doing. Not at all sure why...

Remove all weight groups and set armature parent again for generated rig, not for metarig.

Sadly its the same issue. Its when I try to parent the rig to the character. Parenting a metarig has no issues

Try clearing all transforms on the metarig. You can either clear all transforms, or if you want to keep your transforms you can apply them.


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Knee going a completely different direction from the pole
As the tittle says, i'm still trying to figure out rigging, but no matter what i try, when i think i finished working with the legs, the knee bends unnaturally when i'm imitating a crouching motion

And that's only sometimes, the other times the knee moves completely away from the pole, like it's repelled or something
This is my IK setup ("Talón" means heel, the target, and "rodilla" means knee, the pole), i recalculated the roles and everything all the tutorials i checked said i have to do

bend the knee in edit mode a bit in direction of the pole so Blender "knows" the direction

If Chris' answer doesn't work please share your file

You’ve got the IK limits set up on the knee and such, right?

If by that you mean the chain lenght, yes, i did

Your character looks in the direction of the X-axis. That means it looks to the left or right. You have cut the screenshot so I can't tell exactly. Press the Numpad_1 key for the front view. Rotate your character (mesh and armature) so it looks to you. Apply the Rotation to the mesh and the armature (Ctrl+A). Then try another value for the Pole Angle like 180, 0, or -90. (the value depends on how you've aligned the bones in Edit mode.)


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UV map appears on blender, but saves as a blank image
i was coming back to a project i've abandoned for quite a while, i'm trying to learn about UV maps and making my own textures, but for some reason, with this project in particular, there's something weird happening
When UV Unwrapping the object (Using the smart UV option if that helps), the map appears normally on blender, but when saving the image, it's just a blank, transparent photo

Here's how it looks on blender, but when i save it and put it into GIMP

This never happened to me before, in fact, i remember it working perfectly in a previous attempt, i don't know what am i doing wrong

Can you explain the process that you followed to save the UV grid?, my guess is that you did not select the grid during the saving operation.

I unwraped the object with the optioned mentioned above, and with it selected, i opened the UV Editing tab and saved it, it looked like the first picture posted

maybe what you want is to save the UV layout (and not the image, which is transparent)? In that case in the UV Editor > header menu > UV > Export UV Layout

That was it!, thank you so so much

What you want is to save the UV layout, not the image, which is transparent. To save the UV layout, go into the UV Editor > header menu > UV > Export UV Layout.

Thank you moonbots, I was stuck doing this project and nearly abandoned it, your comment was a big help, just logged in to say that. Thanks again.


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I was wondering how you'd go about creating a visible cone of light that fades
I was wondering if it was possible to do something like this but also apply the effect used in this to the cone of light in Cycles.  I was told by someone else that I need volumetrics, but I'm not quite sure how to do this.

You can apply such falloff manipulations to any lamp. For volumetrics, see http://blender.stackexchange.com/q/8001/599


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subdivision surface sharp edges problem edge loops and creases don't work
how would i go about sub-surfing this and keeps its sharp edges?

more specifically i am having difficulty with subdividing the the plate like objects on its upper arms and thighs,i have tried the usual methods such as moving edge loops and adding creases but they all leave some kind unsightly deformity, especially when combined with the solidify modifier.
most of the other parts of this model such as its torso and head subdivide without issue.
just what am i doing wrong and how do i make its arm and leg plates smooth with deforming or losing definition?

this was marked as duplicate and linked to a question which told me to use supporting loops and creases which as i already stated doesn't work.

Related: http://blender.stackexchange.com/questions/6425/keep-sharp-edges-when-using-subdivision-surface

Did you try a Bevel modifier with an Angle limiter?

i did try just now it didn't help, perhaps you could be specific about its use? it did seemingly nothing when i tried.


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frame_change_pre handler only works once
I'm trying to change a text object on each frame in Blender 2.75a using the code from a previous answer (How can I make dynamic text in an animation?). With my script the text value is coming from the lens property of a camera which is keyframed.
I have added the script to the blender file and changed it to use the camera lens value. When I hit Run script and then move a frame it updates the text object in the 3D viewport as expected. But then when I move another frame it does not update. Nor does it work for Alt+A or if I render a sequence of frames.
As per Ray's suggestion I added a print function which showed frame and lens value. As I moved back the frame back and forth the frame number updated; however the lens value only changed the first time after hitting Run Script and then remained the same in the console. The lens value was changing in the UI.
Code is here: http://www.pasteall.org/61366/python
I've tried code to clear the handlers (frame_change_pre.clear()) and closing down Blender and reopening to reset everything and the same behavior occurs.
Zeffii's suggestion of moving the camera_lens = bpy.data.cameras['Camera'].lens line into the function partially worked.
My understanding of the problem now (thanks, everyone) is that when the script is run for the first time it establishes the handler and sets the variable with the lens value. From that point on when the frame moves the handler only executes the function and since the variable that holds the lens value is outside the function it is never updated. Moving the lens variable assignment to inside the function now means it is updated each time the handler is called.
However, now the update lags one frame behind. i.e:

start on frame 1, UI and 3D view = 16.0.
Move to frame 2, UI = 16.9, 3D view = 16.0.
Move to frame 3, UI = 17.8, 3D view = 16.9.

I'm guessing the python handler is executing before the keyframe value is calculated. Tried changing to frame_change_post but that didn't seem to work either... suggestions?

A print statement in the handler is a quick way to test if it is being run, by looking at the system console.  If it is being run each time, perhaps the property (camera lens value?) is not updated.

axb2035, please share the smallest amount of code that demonstrates the problem. Something like: https://gist.github.com/zeffii/3e98014f3ee7b050eb03

move camera_lens = bpy.data.cameras['Camera'].lens  into your function

recommend you edit your question and title to focus on the current problem. (off by one frame in ui vs render) . The problem isn't (and never was) that the event handler only worked once, the value wasn't updated because it was only generated once -- outside of the event handler.

As pointed out by zeffi - camera_lens = bpy.data.cameras['Camera'].lens assigns the current value of the camera lens to the variable. That is camera_lens is set to 16.0 when you run the script to insert the handler, this value is then used to set the text every time the handler is run. Only the code within recalculate_text() is run on frame change, not the code before it. What you want is to hold the camera object in a variable and then read the current camera lens setting each time you update the text contents, or to use the full data path within the function.
The off by one issue is the order that things happen. The frame_change_pre handlers are run before frame_current is changed while frame_change_post handlers are run after. frame_current needs to change so that things like a value controlled by an fcurve can be calculated, which allows you to read the keyed value that applies to the current frame.
import bpy

def recalculate_text(scene):
    text_obj = scene.objects['Lens']
    my_camera = bpy.data.cameras['Camera']
    text_obj.data.body = ('{0:.1f} mm' .format(my_camera.lens))

bpy.app.handlers.frame_change_post.append(recalculate_text)


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Proportional Editing moves whole object
I'm trying to follow a video tutorial to learn how to modelling a character in blender. I've reach the point where he explains how to use the Proportional Editing. I'm tryng to do what he says, but this feature is not working in the same way as it works in the tutorial and I don't know why. These are the steps I do :

I activate the Proportional Editing by pressing O
I select a vertex
I press G

What I see is not the movements of a lot of vertex together, but of the whole object. Please check the picture attached where you will see that I've tried to move a vertex with the G and you see what's happened.

scroll your mouse down until you see a circle ( make it smaller )

ohhh I found the error. the circle was too big and I wasn't able to see it. very thanks man.

related http://blender.stackexchange.com/questions/35577/proportional-editing-on-mesh-doesnt-work

You can see proportional size of the tool once it's activated (after pressing O) in the very bottom of the 3D Viewport (where values of probably any interactive tool are shown). Taking into account that value you can deside whether it's too big or too small

That happens a lot, especially if you've set units for your scene. Simply scroll down with your scroll wheel, and the ring will get smaller and smaller, until you see it in your viewport.
Check to see if the "proportional size" number is decreasing.

In a version 2.8, when start moving, resizing or rotating a new box will appear in the bottom left corner. If this box is expanded it will show Proportional Size value.
The easiest thing to do in this case is when you start moving something with the proportional editing, keep pressing PageDown button until you see the radius of influence, because in your case it is much bigger than the object and even the viewing screen port, so it affects the entire object. The radius can be adjusted with the Mouse Scroll Wheel, as already pointed above, or PageUp/PageDown keyboard buttons.

Side note: it seems that sometimes you need the proportional size to be less than zero, so even if you scroll wheel down to zero, if you still can't see the circle, keep pressing page down over and over, and eventually the circle will appear.

Superb, I was stuck and your comment saved my time.


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Rigged model deforms horribly when doing anything in edit mode
I'm following this tutorial that models a puppy.
After modeling the puppy in the tutorial it's shown how to add a meta-rig. I set up all the bones then realized I needed to do some more modeling.
When I try to do this in Edit mode it goes ballistic and explodes in all directions. I have read something on this forum that sounds somewhere close to this problem. The suggestion is that you can click the "remove rigid body tools" button under physics in the tool side panel. I did that, but it didn't work.
I even went as far as to delete the entire rig to see if that would work but that didn't work either. Any help would be appreciated.

I have learned that if you have shape keys and one of the shape keys is selected other than the basis, it will do as I described in this post. If you simply click the basis on your shape keys panel and you will be able to edit your mesh/model at will.


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How to align vertices with other vertices
I'd like to select a vertex, then select several other vertices and make them somehow aligned with the first one by e.g. Z axis.
Here is example picture of what I have - the highlighted vertices are ones which I'd like to align.

If possible can someone explain me how to do it.
If it is not, could you provide a good alternative.

I solved using S Z and entering values using the keypad. I do not know if this is the best way, I hope this helps others.

The best way is to select the vertices that you want to be aligned. Then press s to scale, press z to constrain to the z-axis. Then type zero and press enter. Then all of the vertices will be "flat" or aligned along the z-axis.

You could also set Pivot Point to Active and select vertex with desired position last.

You can use the following procedure

Select the whole edge loop (Alt + Select)
Edge Slide (Select + G + G)
Slide whole edge loop to edge you want to align with
With the edge loop still selected grab and place edge loop on any axis.

You must be the newest contributor. Welcome to Blender Stackover.

If you want to select verticies aligned with one original vertex on an axis, first, click Numpad 5 to enter orthographic view. Then consider which axis you want, and click another of the following Numpad values.
Numpad 1: Select on y-axis.
Numpad 3: Select on x-axis.
Numpad 7: Select on z-axis.
Key Z to enter wireframe mode. Lastly, key B and drag your mouse while holding the left button to draw a box around the vertex.


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When I set geometry to origin my character's head gets messed up

I wanted my character to align down to 3D cursor. When I set origin to Geometry to origin my character's head gets messed up. Please help.

Probably this has to do with modifiers added to the object, e.g. Armature or if the head object is parented to another one. The question can have multiple solutions depending on exact case

"When I set origin to Geometry" are you sure what you want is not Origin to 3D cursor?

You cannot change the geometry or the origin point after riggind.

In edit mode press TAB: select the botom faces from the foots

press Shift + S and click cursor to selected

press TAB to set object mode, then press T to show transform panel and go to set origin and click set origin to 3D cursor

Make sure you don't have another object select pressing A to select everything and deselect everything.
Finally select the object and press Shift + S and click selection to cursor(offset)


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How to animate surface fluctuations
I have experimented with Blender before making some simple low poly landscapes.
I found this example online:

The scene I am trying to animate is very similar to the example above but a low poly mountain range. How can I achieve this effect?

You can use a Displace Modifier and an Empty to move the coordinates of the Texture doing the displacing. This produces the "swimming through" effect. Use the Strength slider to adjust how subtle or pronounced you want the effect to be. Keyframe the Empty as needed to get the speed you want.

You can also change your Texture Type and Size to best fit your mesh density:

Rotating and Scaling the Empty produce interesting variations on this effect. Play with it. :-)

One more thing: Here's another way to do it with the Empty coordinates using a driver, so you don't even need to keyframe. If you type #frame into an input field then the value will move with the frame. Then you can change it to frame/20, frame/30, etc. for finer increments (slower change). This method uses Python, so you can "Reload Trusted" or enable "Auto Run Python Scripts" in Preferences.

I actually completed it last night using the method you described but with two displacement modules with noise texture and interweaving the value to fluctuate. I like the idea of using an empty though, ill have a play! Thanks for the input

Glad to hear you got it working! I added one more example to the answer that shows how to move the empty with a driver, in case you're interested.


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How to export object with its texture for 3d printing?
hopefully, this is a simple noob issue. Yes I have seen that it's been asked again and again and again, and I have tried lots of the solutions but I'm still stuck.
I have a model that I have applied a texture to and it renders nicely in Blender.

Ideally I want to export this to Shapeways for printing in colour sandstone, or when I eventually get an Mcor Arke, print it on there. So, I have a few options, DAE and X3D for example, these require the texture to be alongside the file in a zip file, and when I upload them, Shapeways says there is a texture (probably because the zip file included a PNG file), but won't render it. When I look in the X3D or DAE file with a text editor, there is no reference I can find to the PNG texture file.
I also tried this post on using the blender render engine, but it still doesn't have a reference to the texture when I export the object.
From when I used to do scanning, PLY seems to have all the image data in the file, so I tried that. Interestingly, Paint 3D recognizes PLY files and renders my bust scan... but, still no model of mine. I thought it may be the mirror modifier, but checking the export attributes, it applies those and includes the UV data, and I applied it manually to test anyway, but no.

Stumped, I continued my search. There was this post about not using nodes, but as I walked through the screenshots, I didn't have the "Mapping" tab that was there, then I did something somewhere and it was there, but it didn't have a UV option for coordinates, when I did the original unwrap I did use the smart option... because I followed a youtube example, so I went back to the beginning of this article, and did the unwrap.... but now I cannot see the material rendered at all in any view. I can't seem to find a walkthrough example of a complex paint job without nodes.
Finally, I found this post. I didn't really understand the explanation, but it did mention baking, which I saw in an option somewhere. So I gave that a pop.

Still nothing. So now I'm out of ideas. Any other ideas much appreciated, but, please bear in mind I still don't know Blender all that well.
If you're interested, here is a zip file with my .blend file and texture.
Any help much appreciated before I lose my mind.

Did you try bake your color maps in (I assume) Cycles into image textures, then append your object without materials into Blender Internal, assign texture to its UV map in UV editor and export to PLY as described in the link you mention - https://blender.stackexchange.com/questions/42246/textures-not-showing-after-collada-export? It should work as it won't depend on material nodes anymore but at the same time will rely on Internal export.

I did try the bake bit, it was on the camera icon. It didn't seem to work. I did follow the directions from an imported model but I was unsure where I can then paint the details on the model as I could not load the texture with the unwrapped outlines, or paint directly onto the model. Since I can't see outside of blender where to make my patterns that is also rather unhelpful. I guess if I'm applying a proper texture i.e. rust, or scratches it makes more sense, not hand painting a model.

I originally followed this tutorial where it outlines smart unwraping as part of the UV creation process. I started from scratch, and instead of doing the smart unwrap with island spacing, I just did an unwrap (more like one of the posts I looked at) and things now work as expected. The only downside is that some of the geometry has warped into very small triangles on the PNG file, but this isn't (in this case) a big issue.
PLY's still don't embed the data, but that's a problem for another day :)


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How can I make a hexagonal grill?
How would I be able to create a grill of sorts found on the front of some computer cases such as this one

You mean the grid in the front or the alveolus behind ?

Basically just the air filter grills you see on the front of computer cases. the very fine grill. at the front

Looks like a lot of geometry. If you want to minimize your poly-count, You're probably better off creating a flat grid in an external program (Photoshop/Gimp) with holes of alpha = 0. Make it seamless. Apply as texture. Scale so the holes are small enough.

Unless that computer is hot enough to cook a steak on, it's a grille.

@Kevin I've personally never seen that variant before. It seems both spellings are applicable

Here's a way to do this using modifiers:

Add a circle (⇧ ShiftA> Mesh > Circle) and set the number of Vertices to 6 in the redo panel to make a hexagon:

Take note of the X dimension of the object. With the default radius of 1 it should be 1.732:

Add an Array modifier with a relative offset of .5 and .75 to create a tile-able section with two offset hexagons:

Add an array modifier to tile the object along the X axis.

Note the X dimension of the object now with the modifier. It should be equal to 1.5 * original_x (2.598 with the default radius):

Set the relative X offset of the array modifier to original_x / (1.5 * original_x), or .666...:

Add yet another array modifier to tile the object along the Y axis, with a Y offset of .857, or (1.5 * original_y) / modified_y.

Increase the Count of the last two array modifiers as desired:

Now you have a wireframe, but it needs thickness. Switch to edit mode (↹ Tab), select all (A) and extrude (E). Cancel the transform part of the extrude (Esc) and scale down (S):

Enable Merge on all the array modifiers.

Add a solidify modifier (and optionally a bevel modifier):

In case you might want something more rounded, you can adjust the angle limit on the bevel modifier and toss a subsurf modifier on the end:

Nice technique ! (even if actually the initial question was about the grid from the front on the image, & not the "alveolus" one, which the edited title has overlapped :) - actually the "weaved" wasn't so bad to describe it)

@Aleph I'm not quite sure what grid you're referring to.. When I think of "weaved" I think of something like this, but I don't see anything quite like that in the OP's image.

I don't know, maybe you're right, in fact there's two grids on the ref image, and the one front the front ground is so thin that I can't clearly see its shape.

@Aleph When zoomed in it looks to me distinctly hexagonal, with rather beveled bars.

you're right ! :)

Excellent tutorial! Provides a lot of room for customisation. Note: On Blender 2.93 for the Solidify modifier, I had to choose the Complex instead of the Simple method to get there, otherwise I would have gotten uneven solidified edges.

If you wish to start with an custom radius L instead of 1 m, then all numbers with dimensions of length (radii, lengths, widths, offsets, but NOT ratios) get multiplied by L. In other words: x_orig=L*sqrt(3), y_orig=2*L, and y_mod=3.5/2*L. The factors mentioned change as follows: the x_original is 1.732 --> sqrt(3) * L, the new x_width is 2.598 --> 1.5*sqrt(3) * L, the relative x offset is 0.666 --> 2/3 * L, the second relative x offset is 0.666 --> 2/3 * L, and the final relative y offset is 0.857 --> (3/3.5) * L. Hope this helps!

Note for those wanting more precision: The 1.732 is actually sqrt(3) ≈ 1.7320508075688772. The 2.598 is 1.5sqrt(3) ≈ 2.598076211353316. The 0.666 is clearly 2/3. The 0.857 is 1.52/3.5 = 3/3.5 ≈ 0.8571428571428571. With a radius of 1, x_orig=sqrt(3), y_orig=2, and y_mod=1.5y_orig/(1.52/3.5)=(3.5/2)*y_orig.

EDIT : I just realised that I hadn't included the .blend file for this (I had intended to... why did nobody mention it ;-) ) making it a whole lot of effort to replicate it to use in your own projects!
Anyway, here it is :

I realise that there are already 4 answers to this question but they all address it by creating it as new geometry. I wanted to provide a different approach by using a procedural texture to give the appearance of the grill. In this way we only need to add a single plane - rather than geometry for each individual cell of the grill.
Here's the final result :

This answer https://blender.stackexchange.com/a/67654/29586 developed a material that defined the cells of a regular hexagonal grid. It produces two outputs - a measure of the distance to the edge of a hexagonal 'cell' (used to drive the Strength of the Emission shader in the original solution) and the Vector coordinates of the centre of the corresponding cell (used as the input to a Noise Texture to generate colors of the cells in the original solution).  The following Node Group takes this a stage further by also providing the distance to the centre of the cell, the distance to the centre of the next closest cell and the Vector coordinates of the next closest cell.

By using the Edge Distance to mix between a Transparent and Diffuse shader we can produce the following simple effect :

For a more convincing grid we need to add depth. For a ray to pass through the grill it would need to pass through the 'hole' at the surface and out the corresponding hole on the other side. The depth of the grill will determine how perpendicular the ray must be to be able to pass through the surface. To achieve this we can use two identical hexagonal grids - one to represent the 'top' surface of the grid and the second to represent the bottom surface of the grid. The path of each ray can then be determined by considering how it interacts with each of those grids.

By 'sliding' the second grid to the side based on the angle of the ray and the depth of the grill we can simulate where it would be when the ray reaches the 'bottom' of the grid. In a 'real' grill the ray will only pass through if it is at a steep enough angle to pass through the top and bottom surfaces. The calculation of the position of the second grid can be done as shown below :

There are two parts to this calculation. The first part (top row) determines the direction of the offset parallel to the surface. This is achieved with a pair of Cross Product nodes. The first combines the Incoming ray with the Normal to generate a ray parallel with the surface but at right-angles to the incoming ray. The second Cross Product flips it around the Normal again - by 90 degrees - so it is along the line of the incoming ray (but still parallel to the surface). The bottom row of the calculation determines the magnitude of the required offset based on the incoming angle (determines via the Dot Product with the Normal) and the set Thickness of the grill. The results of these branches are Multiplied together to give the required offset.
The following image shows the interesting regions based on where it strikes the top and bottom grids.

The colors represent the following :

White - The ray is close to a top cell 'edge' and so has hit the top surface of the grill
Red - The passes through one cell on the surface but would be 'out' of a different cell - ie, it must have hit the side of a cell.
Green - The ray is close to the cell 'edge' on exiting the grill and so has still hit the side of the cell (but almost got through)
Blue - The ray enters through one cell and exits through the corresponding cell in the other grid - ie, it's passed all the way through.

Shading the White region with one material for the surface of the grill, Red and Green with another for the edges of each 'hole', and Blue as Transparent we get the following result :

The above material does produce more convincing results - especially in the way more oblique angles result in less light passing through the grill - but the surfaces are still 'flat'. To improve this further we can generate Normals based on where the grill is struck - ie, on an inside edge it will be angled parallel to the surface (perpendicular to the side of the 'cell') while on the top surface (the edge of a cell) it will be closer to the surface Normal. In addition, we can add a curve or bevel to the top surface of the cells.
To achieve this we can use the following material :

Note the calculation of the Normal using a combination of the Cell Vector and 2nd Cell Vector to determine the direction of the Normal of the corresponding cell wall. The Vector Transform node is used to transform the calculated Normal (which will be in Object space) into World space as required for the Normal passed to the Shader.
And this produces the following results :

The material can be used on more complicated shapes - although, as it stands, care needs to be taken since the calculated Normal for the inner edges and upper surface of the cells does not take the actual surface normal into account  (I'm sure this could be improved by tweaking the calculation but haven't yet had the chance to look into it in much depth). However, it still produces reasonable results as shown with this 'wireframe' Suzanne.

Limitations
Note that the shading on the edges of the cells isn't perfect - it can produce odd results with thick grills when viewed at an oblique angle - where the calculated normal is miscalculated as the wrong edge. This is due to the 'second nearest' being the incorrect cell to use for the angle of the ray and is difficult to correct for as it is dependent on the 'depth' through the grill where the ray hits the side. The problem is illustrated by this image :

The result is sufficient for this slight discrepancy to not be generally noticable but if anyone has any suggestions on a way to address this then please do let me know! One potential solution is to calculate the depth at the point the ray hit the cell and to position a third hex grid at that depth to determine which cell boundary is most relevant. However, this would have an impact on efficiency as the hex grid is already quite computationally intensive.
Another limitation is that currently the Normal calculation assumes that the surface is oriented in the X/Y plane. For more complicated surfaces (such as Suzanne), this is not always the case and the calculated normals may produce odd results (such as when viewed from behind). This is generally not noticable but can result in incorrect lighting and/or incorrect reflections - especially on the 'internal' surfaces of the cells. Also, this means it is not suitable to UV unwrapped meshes (stick to Generated or displaced Object coordinates).
Note also that nodes that generate the hexagon pattern require positive X/Y coordinates only. When using Object coordinates (or any other coordinates that could result in negative values), use a Mapping node to shift the coordinates a suitable amount to make sure they're always positive.

That is brilliant - I was looking for something like this a while back. Thanks!

Ok, one solution, for creating a simple grid. If you need a grid which will be filmed from close up, it'll need more tweaks. But for a quite simple one:
create a Plane, Subdivide it once, select the center vertex.

Still in edit mode, hit Space, select Bevel, and fill the settings like in the image below:

Delete the faces selected:

Select all the inner vertices, and hit Space> To Sphere, to make it round shaped:

Now you have your basic hole shape. in Object mode apply 2 Array modifiers to it, one for the vertical repetition, one for the horizontal one

and you have your (simple) grid !

Using the bevel made no changes to the mesh at all

you must be in edit mode, and then set up the config on the left panel, as it is shown on my 2nd image, surrounded in red.
If my explanation has been helpful, feel free to accept the answer :) (http://blender.stackexchange.com/help/someone-answers)

Still nothing i dont even have the loop slide option

wich version of blender?

Im using version 2.75

can you upload your .blend?

Using geometry nodes:

Shift-A  -> Mesh -> Extras -> Honeycomb

(make sure you have "extra objects" enabled in add-ons)

Add a plane and a geometry modifier with this node setup:

add a solidify modifier

result:

Honeycomb is not one of the base meshes of Blender. You should edit your answer to include instructions on how to add that into Blender.

i updated my answer

Thank you! It will be very useful for users of Kiwix (offline blender.stackexchange.com), for they can immediately implement your (good) solution without having to search (and struggle with Kiwix’s search)/troubleshoot why there is no honeycomb mesh by default!

Here's what you can do:
Make a plane, subdivide (Simple subdivision)
Make a cylinder (or any shape you want to punch out of the plane)
Apply scale to both plane and cylinder
Make cylinder child of plane
Set plane to duplicate faces (serach for duplifaces)
Select plane
Press spacebar -> Make Duplicates Real
Select all objects that were created, Join them (spacebar -> Join)
Add Boolean Modifier (Difference) to plane, set it to subtract the "holes'" solid
Apply subdivision
Apply Boolean

How do i make the cylinder a child of the plane and  how do i set it to duplicate faces?

Switch to object properties (cube icon, in the same set where the modifiers tab is).
To set a parent select Cylinder and then Plane in Object Mode and press Ctrl+P, or you have a "Parent" voice under the "Relation" dropdown.
To duplicate faces you have a "Duplication" dropdown, where you can select wether to duplicate None, Frames, Verts, Faces or Group


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I have an edge that does not bevel as expected, what might be wrong?
Here is video of the problem: https://www.youtube.com/watch?v=9rAeFdRckN0
What might be wrong with those edge to bevel in such way?
Edit1 : Here is dropbox link to file. https://www.dropbox.com/s/d7lc0zirimptwcm/wheel.blend?dl=0

Can you upload the file?

@OmarAhmad When suggesting that someone should upload a file it is better to suggest where they should upload it. http://blend-exchange.giantcowfilms.com/ is the preferred location.

I've just gotta say, we've been getting a lot of low-quality questions from new users lately... but this one is really good. It's a generic question, simply and clearly asked, with sufficient supporting information, and without editorializing. Good job, @EvgeniPetrov

Beveling ngons (faces with more than 4 vertices) is not a good idea : results are not really predictable.
Here is a view of the inner geometry with triangles (on the right) :

The upper part of your mesh is good, but the ngon part does not allow to manipulate it well (for beveling, for instance).
So for a good bevel, you should redo this part with quads only (faces composed of 4 vertices), the same way you modeled the upper part.
Also take care of the bottom part (on the left) which is composed of 5 vertices.
To 'repair' the mesh

Go to edit mode
First of all, select all and remove double vertices (some are doubled)
Set face selection mode by Ctrl + Tab then face
Select the two faces which are ngons then delete this faces (X then 'only faces')

Set vertices selection mode by Ctrl + tab then 'vertex'
Select the vertices like below in order to count them (here 18)

Give 18 cut on the bottom part (Ctrl+R then Page Up 17 times)

Select the top and bottom vertices on one side (without the extremities)
Then Ctrl+E and 'bridge edge loops'

Do the same for the other side

Now we have this below, so simply complete the faces for the extremities.

Beveling :

....and this is a good, clear, simple answer, too. Good job.

Is there easy way to seperate face to more faces?

@EvgeniPetrov, edited

Wow! Thank you for the great answer! "Bridge Edge Loops" is what I really was looking forward, did it manually :/

@EvgeniPetrov, doing it manually can be fast too if you use the 'F2' addon (mesh_f2.py)


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How do I achieve the tri view in Blender?
How do I achieve this view in blender??
I've tried quad view but it's not the same effect.
I want to be able to assign different backgrounds for each view separately as Im using it to make a car model.'
Thank you.

EDIT: ok I found out how to do it, you get to any corner of any view and you just drag it. and then from view , you change it to whatever ortho you want.
Now how do I delete one of them if I made one by mistake?

have a look here : http://blender.stackexchange.com/questions/21008/can-not-close-windows-in-interface/21012#21012 and the included link here http://blender.stackexchange.com/questions/5631/how-to-close-view-windows

 LMB the three hash marks in the top right corner of the 3D Viewport and drag to the left to divide the view.  LMB the three hash marks in the top right corner of the right 3D Viewport and drag downward to divide the view again. You can now add a different Background Image to each.
Tri View:

.blend file:

thank you!
How do I delete one If I created it by mistake?

Grab the three hash marks and drag onto the one that you want to close. If my answer helped, please consider accepting it.

http://blender.stackexchange.com/questions/53644/how-do-i-close-unwanted-windows


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How can I specify the position of vertices to create an object using Python?
I have generated a large matrix with the (x,y) positions of all 4 vertices of a rectangle, using a Python script. It's called Matrix1, and has the dimensions (265,2,4)- 265 rectangles, 4 vertices with their x coordinate in the first row, and the y co-ordinate in the second row respectively.
As I am new to Blender, I am unsure as to what commands I would use to actually create rectangles with those vertices.
Any help or assistance would be greatly appreciated. Thank you in advance!
Edit for more information: (UPDATED)
For example:
[[0,1,1,0]
[0,0,1,1]]
are the four vertices for the first rectangle, representing (0,0) (1,0), (1,1), (0,1); in general, if the order of vertices is [a,b,c,d] they should be joined to form edges ab, bc, cd, da.
Could anyone please help?

Something like this (for 2 rectangles)?  [[(0, 0), (0, 1), (1, 0), (1, 1)], [(0, 0), (0, 1), (1, 0), (1, 1)]]

@batFINGER Yes, Matrix1 is exactly like that, but just for 1000 rectangles instead of just 2. My question is how would I go about setting those coordinates as the position of the vertices?

One mesh or separate mesh object per rectangle?  Also do you know about the vert order? eg if the verts are  [a, b, c, d] will the edges be [ab, bc, cd, da] ?  Perhaps edit q with some sample data.

I added some details to the question. Please let me know if there's any additional information required.

Code will create default plane primitive, then add a copy to scene, located and scaled to match each of your rectangles.  This way all will share one mesh.
**(Assuming there's no rotation involved and that each is a rectangle)
import bpy
from mathutils import Vector
context = bpy.context
scene = context.scene
#define some rectangles
rectangles = [[(-1, -1), (1, -1), (-1, 1), (1, 1)],
              [(9, -1), (11, -1), (9, 1), (11, 1)],
              [(0, 0), (3, 0), (0, 9), (3, 9)]]

# add a plane
bpy.ops.mesh.primitive_plane_add()
plane = context.active_object
# copy plane to each rect.
for rect in rectangles:
    r = plane.copy()
    verts = [Vector(v) for v in rect]
    # location and scale for copy from data.
    r.location.xy = sum(verts, Vector((0, 0))) / 4
    r.scale.xy = ((verts[0] - verts[1]).length / 2,
             (verts[1] - verts[3]).length / 2)
    #link to scene
    scene.objects.link(r)
# remove initial plane
scene.objects.unlink(plane)

I got "TypeError: mathutils.Vector()" upon running your code, in your 16th line (with the for v in rect). Could you please advise me as to what I should do?

@Ishan With just the code above, no edits, blender version 2.77?  Have you added your own data, Vector(3) for instance will throw a type error.

verts = [Vector(v) for v in rect] # This line gave me a TypeError: mathutils.Vector() ; yes, I'm using Blender 2.77. Is there some way I could send my code to you?

Notice the difference between [[(0, 0), (0, 1), (1, 0), (1, 1)]] and [[0,1,1,0], [0,0,1,1]] .. if you are using data of this form it is what is causing the error.  You edited the question and changed to this format 2hrs ago.

I made adjustments, and converted my data of the latter form to the form you used (it's now in [[(0, 0), (0, 1), (1, 0), (1, 1)]] form)

Is it working Ok now?  You can always paste sample code either in the question or at http://pasteall.org  Another format could  be [(x,y), h, w]  ie location, height and width. Would need to change code accordingly.

No, still getting the same error on line 210: http://www.pasteall.org/71664

Put a print(rect) statement before 210.  If it isn't of the form [(0, 0), (0, 1), (1, 1), (1, 0)] then you will need to edit YOUR code accordingly.

I found the mistake. Thank you very much for all your help!

I had a small follow up question; say I multiplied the vertices by the rotation matrix. How would the code change?

This Code will create the mesh object with your faces.
As for the Colors you will have to decide how you want to store them.
With a different material per face?
With vertex colors?
In an image (UVMapping)?
It depends on what you want to do with your Object as to which answer is best for you.
import bpy
import bmesh

vertlist = [[(0, 0), (0, 1), (1, 1), (1, 0)],
            [(2, 2), (2, 3), (3, 3), (3, 2)]]

def create_mesh_object(context, vertlist):
    bm = bmesh.new()

    for faceverts in vertlist:
        bm_verts = []
        for vert in faceverts:
            bm_verts.append(bm.verts.new((vert[0], vert[1], 0)))
        bm.faces.new(bm_verts)

    me = bpy.data.meshes.new(name='MyMesh')
    ob = bpy.data.objects.new(name='MyObject', object_data=me)
    bm.to_mesh(ob.data)
    context.scene.objects.link(ob)

create_mesh_object(bpy.context, vertlist)


text:
Why does moving one side of my rigged character move the other side as well?
Hi I'm new to Blender and I was trying to animate a character. I set the mesh parent to the armature with automatic weights, and when I tried to move the left arm the right arm moves in the same way (same situation with every symmetric body parts). The armature on the other side doesn't move, just the character. Could someone please help me with making each body part move independently?
Thank you very much.

You probably have a mirror modifier below(i.e. after) the armature modifier. Move the mirror modifier above the armature, or better, apply the mirror modifier at this point so  you can rig and animate the character.

Why?
As Mike Pan mentioned- this is because you have a mirror modifier on your mesh, not your armature.
How to fix
Either A. Apply the modifier or B. Remove it
-Happy Blendering!


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faceloop selection does not work
I want to select a faceloop by using Alt +  RMB, but if do that, Blender selects all the faces of my mesh. What could be wrong? Are there other ways to select faceloops?

What does your mesh look like? Can you include screenshots?

Here's the screenshot.

Is it possible that this mesh actually is one continuous faceloop?

Aha, I've checked this out and you are right. So now my next challenge is to make the torus with seperate loops. Thank you both for answering.

Was the poke and convert to quads used when creating that torus ? I didn't see anything unusual and couldn't really get how could be there one faceloop.


text:
Join Overlapping Terrain Surfaces
I am trying to create a terrain surface for laser slicing.
I have several publicly available terrain surfaces. The surfaces have some overlapping, but the overlapped faces are not same on both surfaces.

I finally want to have an object similar to below without internal surfaces

I tried to extrude individual surfaces, and join. There are internal surfaces remained.
I tried to extrude individual surfaces, and do boolean operation: Object A union (Object B difference (Object A intersect Object B)). There are still internal surfaces.
Can anyone tell me how to do this?
I tried to cut the overlapped surfaces by bisect tool at a specific coordinate (say at certain $Y$) on both surfaces, then extrude and join. but there are still internal surface.

Finally, here is my solution.

cut one object's edge by bisect tool at position very close to another object, keep a gap between the two objects.
join the two objects into one.
enter edit mode
select the two edges at the sides of the gap
use edge bridge tool.


text:
Sculpting not working
I haven't found any solutions to this after searching everywhere. The sculpting just doesn't happen.
The brush is showing. But when I try to sculpt, nothing is happening (I have selected the mesh and then went to sculpting, so that's not the problem).
I have also seen that the sculpting is working on other meshes. I really don't want to start another sculpture.

does your object have enough polygons? If it doesn't have enough polygos, there won't be anything to sculpt. So you can either subdivide it or enable Dyntopo or give it a Multiresolution modifier. Try Dyntopo.

A long shot but could you check your normals, might be flipped

Select the grab tool (G) and ensure the brush is large enough.
To sculpt properly, you need enough polygons to operate on.
If you don't have them, consider retopologizing via the remesher option in the sculpting mode and experiment with different voxel-size levels (smaller makes more polygons) of to find the outcome you want!
Don't go too low too quickly or you will lose the ability to make coarse changes to the sculpt: One's workflow should begin coarse and become fine over time when sculpting in detail-passes!

I had this problem only to find that I had somehow masked the entire model, which blocks sculpting on the highlighted areas. If your model looks off-color to the standard viewport base color you have applied in sculpt mode this could be the issue.
To remove all masking go to Sculpt Mode > Mask > Clear Mask, or use the default shortcut Alt +  M


text:
Alpha channel not responding to blur?
Here is a still of a shallow focused camera of a few flowers. As you can see the pink flower alpha blend is not responding to the blur... How do I ensure it is blurring like the rest of them?


text:
How do you turn off an objects interaction with others in the scene, but still show up in the render?
I have several objects in a scene and my goal is to add a background image of some clouds and blue sky.  I downloaded a nice HDR and brought it in using add>image>background.  Looked nice but it did not show up in the render.  After some research I found I needed to import the image as a plane, which I did.
So I enlarged it and moved it to the back.  Its an outdoor scene so I am using the sun as a light source.  When I view it in material preview it looks fine.  When I go to rendered preview it acts like a large wall in the scene.  It casts a shadow and looks very dark, like a photo at night.
So is there a way to stop this plane from interacting with the scenes lighting but still be able to show the image in the final render?
I am using Blender 2.83

In the plane's material settings you can make it shadeless, and forbid it to cast any shadows. But there are better options to add background image. Look for some compositing tutorials "blender add background image in render"

You don't need to put it as a plane, you can just import it as a background. You might have the background as alpha, if you do, turn it off.


text:
Blender rig problem
Trying to add automatic bone weight to my rig. Blender stops responding and i have to quit it. When i open the file it says “for security reasons automatic execution of python scripts in this file was disabled”
And this goes on for an infinite loop.

Hello & Welcome to https://blender.stackexchange.com/ Please try to use a title that reflects the content of your question so that it is easier to see what this is about. Also, in this case it might be helpful if you share your blend file via https://blend-exchange.com/, because without that information it might be difficult to answer your question. You may also want to look at the Help Center posts, starting with this article: How do I ask a good question?

How many deform bones do you have and how many triangles does you mesh have?


text:
How can I repeat a mesh using multiple empties with unequal distances?
I have a mesh and some empties with unequal distances between them and I want to repeat this mesh and place it where those empties are.
I know that if the distances were equal, I could use an array modifier and object offset. How can I do this for multiple empties with unequal distances?

Collection Instances
First put your object(s) into their own collection.
Select all your Empties. Go to the Object Properties, expand the Instancing panel.
Now it is important you keep ALT pressed until the end. This will propagate the modifications to all selected objects.
Click on Collection while still maintaining ALT and choose the collection you want to instance.
If you want "real" meshes afterwards, you can use CTRL + A > Make Instances Real or Object > Apply > Make Instances real.

Troubleshooting :
If you don't see any change after these steps:

Make sure the empties are not in the collection you are trying to instantiate
The Instanced Collection's origin might be different from what you'd expect. You can tweak it by following these steps.
ALT + Click doesn't work because you are emulating a 3 button mouse :

Add a collection instance only for one empty. Select all the other empties too and make sure the instance collection is "active" (yellow outline). Then go to Object > Make Links > Instance Collection or use shortcut CTRL + L.

Wow. Gaping hole in my understanding of Collection Instances.  I had no idea you could do it this way round. This will save so much time.

Yup, Adding a collection instance is just a shortcut to manually adding an empty, and then repeating these steps :) mind = blown :D

.. and you can follow up with Ctrl-A >  Make Instances Real, if you want to.

Wow... That was really good!!! But I have an "issue". If I try it to an empty project, with just a cube, it "works". In my project doesn't!!! Instead of repeat the object, repeats only an empty collection!!! Any idea why is this happening? Please take a look here ( https://drive.google.com/drive/folders/1Tfv2zMmZ4zab9XhnQiucUidkDA_J4srm?usp=sharing ).

Make sure your empties are outside of the collection you are trying to instance :) The limitation prevents an infinite loop of instancing

I have already tried that and I still have the same issue!!! :( Is there any case to have to do with any kind of settings etc?

Maybe share your blend so I can take a look ? https://pasteall.org/blend/

Of course, here it is ( https://pasteall.org/blend/16931f10bcc345b2a736e63ac5cfd5e8 ).

@Gorgious I think I found it... Mesh should be placed at the center of world and mine wasn't!!! Or should not?

You identified the problem :) You have two solutions. Either model at world origin or you can offset the collection origin. See my other post on the subject https://blender.stackexchange.com/questions/137523/how-to-change-the-origin-when-moving-a-collection-instance

Thank you very much!!! :)

@Gorgious "Now it is important you keep ALT pressed until the end." It seems that this not work if you have activated "Emulate 3 Button Mouse" in preferences because then it only zooms in/out editor while pressing alt. How this ALT pressing should works if I have that "emulate 3 mouse button" settings activated?

@SakariNiittymaa Added solution to the answer


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Symmetrizing bones only symmetrizes one single bone
i'm new to blender as a whole and i was trying to dip my toes into rigging, thing is, the symmetrize button only symmetrizes the control point bone at the knee

I tried rotating it, selecting different bones, even closing blender and opening it again, what am i missing?

Are your bones named correctly? Only bones with Blender's naming convention will symmetrize. From the docs:

If you have a bone that has a copy on the other side (a pair), like an
arm, give it one of the following separators:
Left/right separators can be either the second position “L_calfbone”
or last-but-one “calfbone.R”.
If there is a lower or upper case “L”, “R”, “left” or “right”, Blender
handles the counterpart correctly. See below for a list of valid
separators. Pick one and stick to it as close as possible when
rigging; it will pay off.
Examples of valid separators:
(nothing): handLeft –> handRight
“_” (underscore): hand_L –> hand_R
“.” (dot): hand.l –> hand.r
“-” (dash): hand-l –> hand-r
” ” (space): hand LEFT –> hand RIGHT

Note also:

If the side of the bone cannot be determined, it will be ignored.


text:
Can we visualize pressure drop regions too in blender ? ( In fluid simulation )
Is there any possible way to have a look at pressure drop regions too in Blender Fluid simulation ?

you can use a simple force field for that (of course you should not use so high strength as i did here: