text:
Why does my material disappear when I rotate it?
I am new to Blender and I can't fix this problem for some reason. The 'L' letter won't show no matter how much lighting I put but when I rotate it, the letter appears. Is there any way to fix this?

The letter 'L' only shows if i rotate it to the angle of the right earpiece but if I do that, the letter 'R' of the right earpiece disappears. It's like the letter will show only at a specific placement.

Hello could you please share your file? https://blend-exchange.com/

yes, I have already edited my post, sorry I am new to all this stuff.

You need to pack your image (File > External Data > Pack Resources), save again and share   ;)

ok, I have done that

@moonboots Not necessary for the solution, but a good practice.

The problem is that you have plugged the Fac (a greyscale/float value) output of the Magic Texture node into the Normal input of the Bump node. You have to plug it into the Height input. It just works coincidentally without error on one side. And I think you can reduce the Strength value. By the way, the "L" is flipped. Select the face in the UV Editor then scale on X by -1.

yes! It worked, thank you so much!!!


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Why is my liquid simulation not showing?
I have applied the fluid in physics property but the liquid doesn't seem to be showing. Did I overlook something or is there something wrong with my model?

Several problems... first of all, the Effector object which you use for the glass and the Flow object which should become the liquid both have inverted normals as you can see showing in red when enabling the Face Orientation overlay (and you have to switch the objects back to show at least as Solid because the wireframe will not display the orientation):

To fix that, go into Edit Mode select all with A, then Shift+N to Recalculate Normals. Now they should show blue in the overlays.
The next thing is, the glass effector object is set to Is Planar. Disable that, because it is no planar object and it will give problems with simulating the fluid inside the glass.

The domain has a very low Resolution Divisions value with the default 32. To make the fluid distribute better inside the glass I would set it to at least 100.

Then - and this is the real problem for your animation - you are mixing Rigid Body with Fluid simulations - this does not work, they are not interacting with each other. You have made the Flow object a Rigid Body object as well - but this object is not the simulated fluid mesh afterwards. So the ice cubes will not "sink" into the fluid and just lie on top of it.
You cannot make the domain - which will generate the fluid mesh - a rigid body, because then the rigid body ice cubes are inside another rigid body - which will only lead to them being shot out immediately. Starting with the ice cubes above the domain will not work either, they will just land on top of it.
The only thing you can do is disabling Rigid Body on the Flow object while keeping the ice cubes rigid bodies and effectors - this will make them affect the fluid. Problem here is: they will fall to the bottom of the glass, not float and create a massive splash for falling fast through the liquid.
For the last part there is no real solution in Blender with just the simulations. The rigid bodies can affect the fluid being set to Effector, but the fluid does not affect the rigid bodies. So you only animate the ice cubes as if they were landing on water and then floating at the surface.

I see what you are talking about but anyway, I am grateful for your explanation too

source: Stack Exchange

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

sort: votes


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How to model constraints between 'building blocks'?
I am creating an application where users can build a structure by 'clicking' together building blocks. Each block is multi-faced with geomnetry based on an octagon, and the blocks can click on to each other 'face-to-face' only with faces aligned.
I presume I will need to use constraints for this but cannot see how to use those in Blender currently? Any suggestions?

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


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Blender Internal Bake Wireframe
I am trying to bake a texture for a mesh, a simple diffuse material with the wireframe on top of it. I'm trying to get the effect you can see here: https://youtu.be/7dK1VVtja5c?t=9s.
I need to bake the entire texture for use in Unity. I tried Cycles+Freestyle, it works well, but Freestyle can't be baked as far as I know. I tried the wireframe modifier, but that means having a much more complex mesh, if the surface is flat I want a flat mesh there.
So I came back to Blender Internal, since I don't need any fancy light effect anyway. The wireframe material works great, but I couldn't find a way to bake it on top of the diffuse material...
Any idea?

If you have freestyle done, you can export it to .svg format and then import svg back in blender (Note that not every svg imports correctly, so it may not work).

You just can go into the UV editor and choose Export UV layout. This is a good texture for wireframe Objects. Just combine it with your diffuse map (Gimp) and you have your wireframe Texture.

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


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Using mathutils.geometry.box_fit_2d
How does one use the angle returned from mathutils.geometry.box_fit_2d?

For example, in the image above the face is selected & the following is run in the console. (There is no transform on mesh object, so vert coordinates are global coords)
>>> bm = bmesh.from_edit_mesh(C.object.data)
>>> points = [v.co.xy for v in bm.verts if v.select]
>>> points
[Vector((39.5, 125.0)), Vector((40.25, 107.0)), Vector((107.0, 163.0)), Vector((80.5, 159.5))]
>>> a = box_fit_2d(points)
>>> degrees(a)
50.00498629110601

The plane (the square) is rotated 50.005 degrees.
I've found a couple of example usages generally for UVs http://www.programcreek.com/python/example/56195/mathutils.Vector.

The angle returned by box_fit_3d is the angle by which the given points have to be rotated to best fit them into a rectangle aligned with the axes.
The example script linked in your question – currently there is only one script with a call to box_fit_3d – does indeed use the angle to calculate the coordinates of the rotated points:
angle = mathutils.geometry.box_fit_2d(cos_2d)

mat = mathutils.Matrix.Rotation(angle, 2)
cos_2d = [(mat * co) for co in cos_2d]
xs = [co.x for co in cos_2d]
ys = [co.y for co in cos_2d]

But if you instead want to fit the original points into a rotated rectangle then you would have to rotate the rectangle by the negative of that angle.
The image below shows the face from your question together with a plane rotated by −50.005 degrees instead.

If you're also interested in the optimal size of the rectangle I guess it's still best to calculate the rotated points and then determine the smallest and largest coordinates like it's been done in the example script.
width = max(xs) - min(xs)
height = max(ys) - min(ys)


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Python RNA getting the names of Vector axes. (eg "g" is color[1])
I've been playing around with DriverTarget data_path in a script. The data path, from the target.id object for the x location could be either "location.x" or "location[0]"
Is there a way of determining the name of the axes in different vector classes, like Vector ("xyz"), Quaternion("wxyz"), Color("rgb") ... or "hsv" and so on.
Currently I'm just hardcoding a lookup table.

not sure if I understand the question right. Do you want to feed object.location[0] somewhere into a function and get "location.x" returned?

yeah I'll put some sample code in to clarify.  Basically yeah.. how do I know that x is index 0 of obj.location.

d=[1.0, 2.0, 3.0]  / v=Vector(d) / for c in "xyz": print(d.index( getattr(v,c))) ?

I still need to know it's "xyz"  would fail for  color.r = color(0) would need to be "rgb" and quaternion.w = q(0) from "wxyz".   If I hard code in the lookup table its just "rgb".index("r")  ... but how do I know its "rgb"? at the moment I check that it's a Color class and then assoc that with "rgb"... is there a way of getting "rbg" from the class?

if you look at mathutils_Vector.c line 2330 that seems to be an indication that there is no information from Python (of course this is just an hypothesis...)... Same thing for color, line 805

I understand nothing but below the line 2330 there is a Python script which could interest you

Yup still hard codes in axises = "xyzw"... looks like I'll stick with the classname: axises lookup table

Guess you've tried this already, so forgive me if it doesn't suit your needs. It's also using hardcoding via a dictionary, the test runs based on the type of the property and the axis to test on:
import bpy
from mathutils import Vector, Color, Euler, Quaternion

classMap = {
    Vector:'xyz',
    Color:'rgb',
    Euler:'xyz',
    Quaternion:'wxyz'
}

def returnIndex(_driverProp, _axis):
    dictVal = classMap[type(_driverProp)]
    return(dictVal.index(_axis))

print (returnIndex(bpy.context.object.rotation_quaternion, 'y'))

authors: Екатерина Яковлева


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Is 3D viewport render time exposed in python?
When 3D viewport is in render mode, ie SpaceView3D.viewport_shade = 'RENDERED' Can the  render time be gleaned or estimated using python?

3D view in rendered mode taking 12.63 seconds.

As far as I know this is implemented in C and no accessible with the python API.
However you can probably create a handler for scene_update which:

iterates over all areas and check if area type is 3d view
if so check if the view type is rendered
and if it is start a timer and use some approximation algorithm to record the time
however if the view type is not rendered or there are no 3d views and the timer is running, stop the timer.

Read more:
Render Time Estimation Addon
Cycles Time Estimation


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Array of curves deformed by texture image
I want to generate geometry with curve to mesh, where the path along which the curve is extruded is displaced in one dimension according to the pixel value of an image. Let's assume the image texture has a black square in the middle, the deformed paths should look something like this:
---------
---------
---------
---___---
---___---
---___---
---------
---------
---------

for a 9x9 pixel image. (the mapping doesn't have to be 1:1, but I assumed it would be the easiest)
I've tried to find ways to split the image into rows of pixels, using the "deform curves on surface" geometry node, the displacement geometry node, vector math node etc. but I can't figure out a way how to map the texture onto the displacement of individual objects according to the corresponding row of pixels.
The cross-section of these shapes is important which is why I chose the route of "Curve to Mesh" but I'm certainly open to other approaches.
Edit: blend file attached. There is not much there yet. I managed to create an array of curves that I can use "curve to mesh" on. But I don't know how to proceed from the texture map. Obviously there is something missing at the red link.
Edit2: cleaned up the file & packaged the texture.
V2:

Hello and welcome Norbert, could you please post your .blend here: https://blend-exchange.com/
so we can really see where you are at?

Difficult to see anything , you didn't pack your image, please pack it or post it...
perhaps take a look here: https://blender.stackexchange.com/questions/254256/geometry-nodes-image-texture-mapping-how-to
and try this: https://blend-exchange.com/b/5WdaGE1X/

Thanks for the example. That looks exactly like what I'm trying to do! Will try to replicate it.

It seems my issue was with the PNG I used, since it was black and transparent without any other color... Thanks again for your help!

Your welcome, I didn't do much...

Actually, I have one more problem. I can't resize the image texture and have to adjust the size of my object accordingly. The only way I can find to resize a texture is with the Mapping and Texture coordinate nodes, which are not available in the geometry nodes. Do I have to through a "material" node setup to accomplish this? (sorry don't know the correct terminology yet)

Could you update your blend (with packed textures)?

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


text:
Using a mesh to "Cull" a set of rigid body objects without affecting the physics simulation
I would like to create the effect of a small box that has a large amount of objects animating out from it.
Final project will have all the objects as rigid bodies being pushed out from a rigid body container (shown as the red block in the animated gif)

Desired Outcome

I have a container that is housing all the objects in side of it, then I animated the balls coming out.
The Final project will be done using rigid bodies hence why I have a container, the balls will be rigid body presents and then I use a plunger to push all the presents out of the box, Balls are just representing a proxy for various meshes
The issue I am having is that I cant find the correct way of using the container as a sort of "HOLDOUT" to hide the balls but still allowing geometry behind the container and balls to come through.
In a simple example as per the attached file I would usually just composite a clean plate, but the project I am working on has complex camera moves, environment and characters, so finding a solution inside of Blender is extreamly important.

I have attempted using a Light Path - Transparent Depth node in the shader editor without luck

I have tried turning it into a shadow catcher and turning off its shadow visibility also with no luck

Is there any particular reason why it has to be the complete number of objects? Are those all exactly the same like in the screenshots or varying ones? Is the camera view fixed or moving? I ask because people often show a simplified version of what they actually want and when you provide a solution they say, "well the real scene is a bit more complex..."

Hi Gordan, I have just simplified the entire file down to solve the specific issue I would like to solve, the final project is a scene with a moving camera, multiple shaped rigid body meshes and a rigid body container that I use to constrain the object inside of, then I animate a plunger to move all the object out of the box,
Heres an example of something similar, imagine a Uber food delivery motorcycle arriving at a location, they open up the box container in the back and an endless amount of food delivery packages stream out

You see, it's good to know that and posting that in the question because now I can throw my particle solution into the trash and do not have to work it out further.

Will update the heading to be more descriptive thanks for the feedback Gordon

You could use a Boolean modifier on your objects:

Thanks Moonboots, I was thinking about a boolean solution, in essence culling the objects within a specified mesh,
However I just need to confirm that the rigid body physics would still function, and that it wont do a "POP IN" explode due to the mesh verts changing

It may not work well with some meshes but we don't know how they look like. You could also try with the Compositor, it all depends on the storyboard

@MeestarP The rigid body physics will not work if you remove the geometry of the active rigid bodies with a Boolean modifier. For that you first have to bake the simulation into keyframes and then use a Boolean modifier on them. But of course you cannot change change the simulation anymore then.

it should work with physics, here is a try: https://i.postimg.cc/sfJMHf1h/anim.gif of course the boolean could not work fine with some topologies

@moonboots That's just one rigid body falling down with gravity. As I understood the explanations in the comments under the question, he wants to push objects out of the box with rigid body physics and interacting with each other... good luck with it when the object meshes to be pushed out are deleted by the modifier at first... The problem is, when the meshes are deleted/hidden by the modifier, then the rigid bodies will not show the meshes coming out of the box. At least not in my Blender. The objects behave as if they had meshes, but they are not visible.

This is how it looks in my Blender without removing the spheres with a Boolean modifier (I have x-ray enabled to show what's going on inside: spheres getting pushed out. And this is what it looks like if I remove the spheres with the modifier... all spheres except for the first one which was not within the culling object and a remaining slice of the second sphere are visible, the rest of them just show the origins but behave as if the spheres were there: spheres not visible.

Okay, now I'm interested in your file and/or Blender version... I have no idea what kind of magic you are doing there :D I tried the same simple setup: an icosphere falling through a cube. I have three versions, at the start one sphere is above the cube, fully visible, the second is half inside the cube and only half visible, the third sphere is inside the cube and completely invisible. All spheres fall down and remain in exact the same visibility state which they have from the start. How is yours disappearing and reappearing? three variations

here is my version, have enabled Rigid Body > Source > Base?

Sorry, did not see your comment earlier because I wasn't tagged... ah okay, I see. At first I had the Collision Shape set to Sphere for simplicity, there you don't have a Source setting. But I switched to Convex Hull because the OP said it would be "multiple shaped rigid body meshes", and left the default Deform option. Turns out now of all options, the default one is the only one where it does not work  Setting Source to Final works as well... //EDIT: It did work with final, now after switching back and forth it doesn't work anymore, only in Base mode... weird.


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Rotate/Twist/Swirl points but using "distributed on faces" and a Length Property from center
What I want to create: A swirling particle galaxy, where the particles not only swirl globally, but also additionally rotate around a smaller axis, that also undulates on the z axis Reference of movement similar to the Sentinal swarms in the Matrix movie

Restraints: In the example I have used a Mesh to Points to illustrate the final look, what I need to use is a Distribute Points on Faces in combination of distance to center and a color ramp so I can control the overall radius of the galaxy as it swirls to its center.
What I have tried: I have tried to use a curve profile on a curve circle to generate the points on the smaller curve circle (Creating a Torus shape) and rotate the profile shape.
This works but.... the restriction I have is that I need to generate the points on a disk shape so I can build a swirling galaxy particle system and the above solve doesnt solve that workaround

Here is the animation reference mockup:

it would be helpful if you could link to a video/animation how it should look like.

Thank you Chris, I have added a mockup of the animation to show the particles rotating

so you wanna an additional rotation around the circles tangent, is that right? like this: [1]: https://i.sstatic.net/19ftOcM3.gif

So if i understood your right, you want to have an additional rotation around the tangent of the circle for each particle.
I don't add "additional" noise here, just to make it easier to understand. So basically you need the rotation axis for each point.
Therefore i first save the "original" center point for each point which is exactly on the circle. The tangent on that point is the cross product from the center point to (0,0,1). So you just have to rotate around that axis.
This node setup does that for you:

for simplification for the calculation i moved the global z-axis rotation after that rotation.
The storing of the center for each point is made after the mesh to points node:

whole node tree:

result:

Hope that helps. Happy blending.
Note: if you understand this setup, it should be very easy for you to add random offseted rotation to your points. I just wanted to keep it simple to make it easy to understand what's going on.

Thank you Chris that helps me a great deal, I can definitely move past my blockage with this.
Mucho thanks :)

de nada, you are welcome


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How do I make an arrayed object fit a 3D curve?
I'm trying to add stitching to a shoe, and I started by making a single stitch, then using the array and curve modifiers to try and get it to conform to the 3-dimensional bezier curve I created.  It seems like once I select the fit curve option under array and select the curve, the stitch is only being arrayed a portion of the length of the curve which is in two dimensions.  The stitches are also no where near the curve after I selected the bezier curve in the curve modifier.  The deform axis doesn't help this.
I tried moving the 3D cursor to the origin of the bezier curve, though I'm not sure if I did it right or if that's even the way to fix it.  If anyone could please help me with this, that'd be greatly appreciated.

Update: Please excuse the janky model, but I'm still having trouble.  After following instructions from the answer, the origin of my curve (is the origin the little orange dot?)  won't go to the start of the curve as pictured.  I don't know how to attach the file here.

Could you add the .blend file?

Here is an overview I made on how meshes are placed on a curve: Curve Modifier- not starting at beginning. However your problem seems something else or more than this... I cannot see your curve exactly, but is it a single long curve or multiple segments? Because the Array modifier places the mesh only on the first segments, it does not continue on the next ones. So you will have to separate the curves to individual objects and give them all their own stitches mesh object.

It's a bezier curve that I extruded like 4 times so that I could get the correct deformation.  Are you saying I need to separate the extruded curve into 4 different segments and apply the array and curve modifiers to all four?  Also, I cannot figure out how to attach the file here.

First, you said that the "Fit curve" option of the array modifier isn't resulting your targeted result. That's probably because the transformation isn't applied. To solve this problem press Ctrl+A > All Transforms.
As far as i know, a mesh that should be deformed along a curve, needs to be in the same location as the curves origin.
The origin of the object isn't required to be in the same location, but I usually do that as well, just too keep my scene clean.
If your mesh isn't located at the curves origin, just select it and then shift select the curve, press Shift+S and Num9 or click on the Selected to active option. If your mesh and it's origin aren't aligned, right click > Set Origin > Geometry To Origin.
If you really just want to move your mesh without the origin beeing affected, you have to do that in edit mode. But before you enter edit mode, select your curve, press Shift+S and Num2 or Cursor to Selected, to move your cursor precisely to the curves origin. Now go into edit mode with your mesh, press A to select all, then again Shift+S and Num7 Selection to Cursor. If you want a specific vertex, edge or face to be exactly at the cursor rather then the median point, switch your Transform Pivot Point to Active Element.
At this stage, your mesh should deform along the curve mostly as desired. However it may be still a bit off or the orientation isn't quiet right. Either way you have to do these alignements in edit mode, it helps to display the curve and array modifier in edit mode.

Very good and detailed answer. One thing, depending on the mesh, Geometry to Origin i.e. placing the mesh centered on the origin might not always be the best solution if you want to fit it on a curve, because then there will always be geometry "before" the start of the curve. If you want the mesh to be starting at the curve's first point, you should place the mesh so that there is no geometry on the negative local X side, the mesh should start at local X = 0 and extend to local +X.

I tried following the answer above step by step but I'm still having difficulties.  When I tried moving the single stitch mesh to the curve's origin by selecting both the mesh and the curve, then shift+S > Selected to active, the mesh moved close to the origin, but not exactly on it.  Furthermore, my 3D cursor is not moving to the curve's origin.  It's staying put right in the middle of my stitch mesh which still won't move to the origin of the curve.    I'm also not sure what you mean by placing the curve so there's no geometry on the negative local X side.

If you mean part of the stitch mesh will extend past the origin of the curve, I'm not too concerned about that in this instance.

Thank you and sorry to the people who answered, but I figured things out a different way.  It decided to work after I changed the array's "Fit Type" from "Fit Curve" to "Fixed Count" in conjunction with the curve modifier.  I'm not sure how I got it to work, but I did.

Yes, the array modifier placed first generates clones, while the curve modifier change their transform individually. I also checked only the relative offset in the array modifier.


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Why is my boolean cut so messy?
I'm wondering what the best way to clean up my geometry from a boolean cut would be.  Or if using the boolean modifier is even the best way to go about receiving the results I'm looking for.
I modeled some specific shapes to use as cutting tools to be applied to the outsole of my shoe model.  As you can see in the images below, the cutting tools are organic shapes with beveled edges on the inside to make a cleaner, more of a 90 deg. cut.  The cuts are the approximate shape I'm looking for, but I'm getting bad shading on all the cuts except for one for some reason.  The one that's clean had it's normal flipped originally, but I had since corrected it.
I need the boolean on both the bottom and the sides and thought it would be easier to just do two separate boolean cuts.  I tried applying the subdiv surf modifier to both the outsole and the cutting tool before applying the boolean modifier and it did not help.  I cntrl Z and none of the modifiers are currently applied.

I flipped the normals of all the objects that were to be cut into, and that cleaned things up, but it made them hollow, so I'll just have to fill them after applying the subdiv surf and boolean modifier


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how do I effectively use the knife tool for fine detail near the edges of a beveled object
I'm currently working on modeling the midsole of a shoe.  I'd like the midsole to have line-indentions on the side of the midsole.  I tried subdividing the object a bunch and then using the draw sharp tool with the sharp falloff, but it wasn't giving me the effect that I wanted.  Instead, I decided to keep it not subdivided and use the knife tool to create the lines, bevel them to the thickness I was looking for, then extrude them inward.  This produced something closer to the effect I was looking for, but it ending up making some discrepancies in the mesh near the end of the lines.  I've tried filling in the parts of the mesh that have unconnected squares, to no avail.  I think I just need some advice for the best way to go about this.
This is the view of the discrepancies in the mesh

This is what the mesh looks like on the inside:

Can you share your Blender project file? Instructions for sharing.

My first instinct would be to give those slits a little bit more room from the bottom of the shoe,  like move the part that actually touches the ground away slightly and also maybe add another edge loop running parallel to the sole.

Welcome. Please use a title that matches the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue in such way that anyone searching for a similar problem may easily find it. Use the [edit] link above, remove anything superfluous, avoid words like "this","issue with" or "question about". Remember, your title is the first thing potential visitors will see, answers you get depend heavily on how inviting it is. See "What is the problem of asking “How do I do this?"

Also, please avoid using phrases like 'need tips' as this sounds opinion-based and is off-topic. This will help prevent your question from being closed.

I figured it out- basically, I just needed to clean up and simplify the structure of my mesh, while not having my knife cuts extend to the outer edge of the midsole, instead, connecting to an additional edge loop just inside the outer edge.


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How do I get rid of double edges/verticies?
This might be a dumb question, but my models always seem to have edges and vertices stacked on top of each other without me even adding a bevel, loop cuts or anything.  I know I can merge by distance but that doesn't seem to work for me, especially with the edges.  I'm just wondering if there's a quick way to get rid of all these duplicate edges.
The edges I think I wan't beveled:

The beveled result, note the black edges:

I'm trying to bevel the tread of this shoe, and i've already merged vertices by distance just enough so that my mesh isn't altered, but when I go to bevel, new unselected edges are appearing, making my bevel unsatisfactory.  I think part of the problem could be me manually filling faces from added vertices and not making sure they're actually connected to the mesh, but not sure.

hello maybe share a part of your object where it happens

I resolved my issue. It turned out that the problem was simply that not all the faces were connected.


text:
Hot key/shortcut for point, edge and face select?
Is there a default hotkey or shortcut for changing between point edge and face select in edit mode? It can be annoying to have to click the bottom every time. Thanks in advance


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How would people usually create smoke?
So I need to create smoke because I'm doing a render of a crashing plane. What I was wondering is that do people only simulate smoke or do they sometimes model it? I've seen people do both but I was wondering which way works well.
Thanks!
NOTE: I'm not sure if it changes anything but I use cycles.

It depends on what you want. For an animation simulation is more than likely the best route, but for a still you have some options. I'd say try simulating it, then fall back to a more manual technique if you can't get it to work the way you want.

@gandalf3 alright thanks! Do you want to put this as an answer?

It depends.
By manually creating the smoke you have as much control as you like, but it will take more time (at least more of your time. Smoke sims can take awhile)
For more realistic results, animations, or less manual work, the simulator sounds like the way to go.
I'd recommend trying to simulate it first, then moving to alternate methods if you are not satisfied.


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Chance of bigger sized particle?
What I want is there to be a particle emitter which emits random sizes but also has a small chance of getting a really big particle. Is this possible? I don't mind if it's integrated, an addon, nodes, scripts or whatever.

can it be on one spot ? or the position also has to be random ?

@Chebhou the position does not have to be random

use texture to control the size of the particles as follows :
 - add a texture to the particle system

in the texture tab change the influence to size

here is the result :

white regions -> full size particle
gray region -> small particles

Yes it is possible. A single object is not limited to one particle system. Add a second one for the really big particles and turn down the emission number.

This is correct but the other one used one particle system and added more detail/worked harder on their answer

I just found a much better way to do this. In the particle settings, under Render, select Group and then simply activate the "Use Count" box. It will then let you choose the ratio between the different particles.


text:
Possible to put XBOX 360 Controller inputs with logic bricks?
I am making a game on Windows with BGE and was trying to add a controller instead of a mouse and keyboard.  I cant seem to get blender to recognize the buttons on the controller when I press them like I would with a keyboard or mouse. Is it supposed to recognize that or is my controller driver not working properly? Help would be awesome!

I think you can use the Joystick sensor; However, you do have to configure it accordingly, using the button and axis numbers.

@CrazyPoo Glad I helped; If it solves your problem, you can upvote (up arrow) and accept (the check mark under the arrows) my answer ;D

http://www.elysiun.com/forum/showthread.php?205580-Use-Xbox-360-controller-triggers-and-analog-sticks-in-BGE

Yes it's possible! Just make sure and calibrate your controller first just to be safe. You need logic bricks, python script and game object (player and ground) to see the results bge-style. Follow these instructions to see how to rotate the cube and make it jump. Okay, let's assume we're starting a new Blender project using the original startup. (I'm using Blender 2.66a for 64bit windows 7 and an XBox 360 wired controller).

Prepare the scene - In the 3d view window, add a plane mesh object and scale it will be the ground. So now we have Camera, light, plane and cube. Then select the cube, in the property's window switch the physics type from static to dynamic.
Prepare the bricks - Then in the logic editor window add one ray sensor, two joystick sensors and one python controller for that cube we selected. Name the ray sensor (I'll be naming mine "Ground"), True & Neg Pulse On, -Z Axis, Range 1.0. Then name the Joystick Sensors (mine will be "Leftstick" and "Jump"). Here's the settings for joystick sensor named "Leftstick"-True Pulse on, Event type: Axis, Axis Number: 1 and all events enabled. Next is "Jump"'s settings-Just simply select Tap. Then link all sensors to the python controller brick.
Prepare the code - In the text editor window add a New script and name it. Back in the logic window, in the python controller brick, select your new script. Go back to the text editor window to write the script. The script should look something like this...
When you play it, you'll be able to rotate cube with left stick and jump with A button!


text:
My bullets dont make the enemy die?
I have a physical bullet that spawns and that has an always motion.  When it hits the enemy it does not make him die.  I am trying to have a collision sensor on the enemy to make it end the object with the Edit Object actuator.  Also, on the collision sensor on the enemy, no propertys are in the list even though I added a property to the bullet?  Should the property be in a certain way?  I left it default cause I did not think that mattered.  Please help!

You must type in that property which you added to bullet(there aren't any lists in this sensor) or set collision to bullet's material(M/P, than choose the one that bullet has).


text:
lost keyframes from timeline
I seem to have lost my keyframes from the timeline. They're still there on the dope sheet and dragging the frameline in the timeline still plays animation ok in viewport but I can no longer see the keyframes on the timeline. Everything is selected on the dope sheet and in the timeline view 'show only selected channels is unckecked (although this seems to make no difference anyway). What on earth have I done?
Thnx,
/gary

Is the object with the animation selected?

I think the object which the keyframes are on was not selected in the viewport.


text:
accessing computed output value from a "NodeSocketFloat" bpy_struct in a GeometryNodes network
I see this same question without no "satisfactory" reply, so i'll just throw it there again.
¿Is it possible to access a value from an output socket of type ? I see many properties out there for the node, except for the one i am really looking for.
¿How to you access it, for instance, via Python?

I tried many ways of accessing the property, this one i found the most intuitive but it is not working:

As correctly stated by the guys in blender.chat, the #python channel, storing attributes in Curve Shapes is not useful because it cannot be retrieved. In order to be able to use an attribute that you have previously stored onto the geometry, you need to store it in a Mesh Shape/Transform object type.
So the solution for me, was to create a new Node Group with all the GN Network and reuse it in a "dummy" geometry cube where, with its own GN network, i would inject the stored value into a new "Store Named Attribute" this time on the cube Mesh Shape.... and voilà.
Having understood this, the next step is to use a function that reads the "AngleBetweenVectors" parameter and substracts it to the "offset" parameter of a Follow Path Constraint. This, done by means of a Driver.
This last step is making Blender 4.1.1 crash when i hit "update dependencies". Not sure yet what the problem could be. Most probably with the "evaluation of the graph", being it maybe "cyclic". Not sure yet.

i found the solution in this post (to the last problem of evaluating the depsgraph): https://blender.stackexchange.com/questions/242227/accessing-geometry-nodes-attributes-in-drivers

Dont retrieve the depsgraph from the bpy.context, but rather, use the "depsgraph" available variable to be passed on to your driver function as an input parameter. This changes everything.


text:
Creating Planetary Rings as Seen from the Surface
I'm creating an exoplanet landscape similar to Mars but with a ring system that will include 2 rings encircling the planet.  This view will be from the surface of the planet looking skyward toward the rings and I'd like the scale to be awe-inspiring but am not sure the best way to go about constructing arcs of such immense size that suggest realistic rings.  Any suggestions?

yes, i have suggestions: please add at least one image how you want it to look like. thx.

Create circles and give them a grainy material?

You could use a Wave and Gradient node to create the concentric circles, use it as a factor between an Emission and a Transparent node, you could add a bit of Noise afterwards to make it a bit grainy:

File:

That's terrific!  I'll give it a try.  I suppose I could just scale it up and then place my landscape model right in the middle of it and it would look very realistic as seen from the surface.  Appreciate the help.

Put it in the background behind the landscape?

Sorry but while I have the material all mapped out, I'm getting tripped up applying it to geometry and then rendering out a ring.  If I begin with a circle, it's still a far cry from an actual mesh.  When I figure that one out, I can either build it inside my landscape and scale it up or save the ring as a Blender file then append the landscape with this model.  Guess I'm still too much of a Blender novice to make that leap from material-to-model.  Too many years with early Cinema 4D modeling with drag-and-drop texturing.  Can you help a bit further on this?

I've added the file, I hope it helps, I've created a circle and give it this material

I've downloaded the file but it does not open in Blender 3.4.  Do I need Blender 4 to open it?

Try to append it (File > Append)?

I did that too, but as soon as I selected the Collection and tried to open it, Blender crashed.  However, I just installed version 4.1.1 and it Appended just fine.  So far it doesn't appear to want to upscale though and I need for it to be extra large in order to fit to scale inside this enormous landscape, but the rings look great and I thank you so much for the kind assistance and follow-up on this issue.  Geometry Nodes Rule!

Thanks, but this is not Geometry Nodes! Just Shader Editor nodes  ;)

Thanks for the clarification.  I have just one more question, these rings need to be far off in the distance above the horizon of this Mars-like planet, so the opacity of the rings must be reduced by a large factor.  They should be semi-transparent.  Any suggestion on the best way to make that happen for this model?

add a last Mix Shader just before the Output, mix the current setup with a Transparent node, play with the Factor of the Mix Shader

I've assembled your transparent node setup but unsure if I have the correct connections.   By the way, I used instead a Translucent Node since planetary rings are more translucent than transparent.  I tried to attach a screenshot, but it said there were errors attaching it so I'll describe how I hooked everything up:  The output of the new Translucent BSDF is hooked into the topmost input Shader of the new Mix Shader, while the Shader output of the original Mix Shader is hooked into the bottom Shader input of the new Mix Shader.  Finally the new Mix Shader, Shader output goes into the Surface.

Thanks for all your help with this project.  Seems it's taken on a life of its own and I'm just not that capable in Blender yet.  Anyway, I've upscaled the ring and placed it about where it should go relative to the landscape, but the render turns the ring a bright white and so far I haven't been able to get that filmy, translucent look for the ring.  Any suggestions?  By the way, I'm still not able to attach a screenshot to these posts.


text:
Hair curves looks weird
I've watched the some tutorials about new hair system and tried to make same way. But i failed. They switch curve display to strip in the render settings before adding hair, but it looks different on me. What am I doing wrong? İn strand hair looks thin and rounded.

hair curves have a large radius by default for real-world sized humans. In the Asset Browser there are Geometry Nodes (GN) assets for hair. Look for the Set Hair Curve Profile and drag it on the Curves object. It will add a GN modifier. In the its settings you can define the radius for the hair.


text:
is it correct to set the camera intrinsics in this way?
I have a 3x3 matrix inside a calibration file that has the intrinsics of my real room inside it. We will call them fx fy cx cy. I would like to know if the code I have written is correct, as I am not sure about cam.shift_y. It comes out a negative value put in because blender inverts the y-axis.
def setCameraParams(cam, fkx, fky, x0, y0):
    pixel2mm = cam.sensor_width/RESX
    cam.type = 'PERSP'
    cam.lens = fkx*pixel2mm
    cam.lens_unit = 'MILLIMETERS'
    cam.shift_x = (RESX/2 - x0)/RESX
    cam.shift_y = (RESY/2 - y0)/RESY
    cam.clip_start = 0.01
    cam.clip_end = 4


text:
Details move separate
I want to set pose to my character. He has some details on his head and neck, its separate object that I joined to body. When I rotate neck bones this details move separate. How to let this details move like part of the body?

How to smooth their deformation?

blend file:

Their vertices are not assigned to any vertex group, first thing activate the On Cage and Edit Mode options of the Armature modifier, select these vertices, at last select one vertex that is not too far and that moves correctly, open the N panel > Vertex Weights > click on Copy:


text:
Cycles does not render with GPU
My blender system tab shows CAICOS in compute drop down...when i render with graphics processing unit compute.my render screen. is blank.but with CPU its rendering.I do not n have any error messages in console window.I have ATI 6490m graphics card with memory 1gb

AMD/ATI graphics cards are not supported currently due to driver limitations. You need a CUDA capable card. (Nvidia)

Is there any other option to use gpu rendering with ati card

Also related: http://blender.stackexchange.com/q/6978/599, and http://blender.stackexchange.com/q/452/599

May I know how to use builds from graphicsall.org

Make sure, that you are running on newest drivers.
On linux run:
CYCLES_OPENCL_TEST=all ./blender
On windows:
set CYCLES_OPENCL_TEST=all
then run blender
Switch to cycles, go to system settings and select your graphic card.
The performance is limited and initial compiling of the kernel can take few minutes. But according to this AMD statement, there is a fix slowly coming in. No words on performance improvements though.

I have the option for gpu compute but render window does not show anything on gpu..But with cpu my scene i rendered completely

What is your catalyst version and what OS do you have?

catalyst version 14.4 and OS windows 7.graphics card ATI 6490m

You may have to install latest beta (14.7) or wait for a  new stable version. But be warned, beta can be unstable.
I got it working on 7970 catalyst 14.6 beta + blender nightly version.


text:
Getting os.system to work in Python Console?
I do this in the Python Console in Blender 2.64 on Ubuntu 11.04:
>>> import os
>>> os.system('ls')
0

>>> os.system('ls /')
0

>>> os.system('echo aa')
0

If that 0 is return status, it implies the command should have executed successfully - yet nothing is printed to the terminal? However, if I do:
>>> os.system('echo aa > /tmp/test.txt')
0

... then there is a /tmp/test.txt file created, with the expected contents ?!
So, the problem is apparently getting the stdout of the system shell routed to the Python console. Is there any way to get this done, so I can see the output of, say, ls or echo in the Python console?

Ok, it seems subprocess can be used instead; note here you have to specify the shell explicitly, e.g. try pasting this script in Python Console:
import subprocess
p = subprocess.Popen(['bash', '-c', 'echo AAaa'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
print(out, err)

The output to that is:
>>> ...
>>> print(out, err)
b'AAaa\n' b''

Note that if you intend to do "piping" bash commands, things get a tad bit more complicated (see Python - How to call bash commands with pipe? - Stack Overflow); so for instance, to call echo BBbb | xsel -b and actually have it succeed (that is, have the string end up on clipboard), you should split the two processes, and establish the pipe via Python:
import subprocess
import shlex
p1 = subprocess.Popen(shlex.split("echo BBbb"), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
p2 = subprocess.Popen(shlex.split("xsel -b"), stdin=p1.stdout)
out, err = p2.communicate()
print(out, err)

The output to this looks like:
>>> ...
>>> print(out, err)
None None

... but the string BBbb does end up on clipboard, as intended.


text:
Local anchor for group master (move/translate/offset of group master moves group instances)?
Let's say I start with the default Blender (2.64) file, except I set the cube to be 1 for all dimensions. At that point, the cube is at xyz location (0,0,0).
Then, let's say I select the cube with right mouse button, and go to Object / Group / Create New Group, and confirm the name "Group" in the "Create New Menu" bar with [Enter]. The selection outline turns green, meaning it's a group "master" (as far as I can see).
Now, let's say I press Shift-A; and choose "Group Instance" > "Group", and set the new instance to Z=2.3; with all selected, the view looks something like this:

Now, let's say I deselect all with A, then select the group master with right-click; and let's say I move it to Y=-2; then the result is:

... that is, it is noticeable that the group instance/clone also moved in respect to its center (note the group instance axes, which remain in the set position)! Which means, I guess, that groups are defined in respect to the global coordinate center (0,0,0) as anchor.
My question is: is it possible to define a group, but in respect to the, say, bounding box center of the group as anchor - such that when I move/translate the group master, the group instances would remain anchored at their set position (basically, at the center of the group instance axes)? Also, is this documented anywhere in Blender documentation (I had problems finding this info)?

(slightly unrelated) note: if in this example, you select the group master only, and then clone it (deep link with Alt-D), then you'll get a copy of both the master and the group instance (4 cubes in all!)

Creating a group-instance is a different thing from creating a linked duplicate.
When you create a linked duplicate, the object data is shared between the two objects, but each object can be transformed or changed with modifiers without affecting the other.

group instances, on the other hand inherit all of the geometry and data characteristics of their defining group of objects and also inherit their transforms with respect to the scene origin, not the group objects center.
The empty of the group instance acts as an additional displacement gizmo so that you can transform the instance, but moving the parent objects in the global coordinate system will propagate that change to the group instances.

Unfortunately, there's no such thing as a group origin-even a temporary one, so you can't produce a group instance that doesn't behave this way.  Programs like AutoCAD have what are called 'blocks' which are collections of entities with a local coordinate system so that you can instance and transform them.  AutoCAD stores block data in a non-graphical part of its and replaces the defining geoemtry with an instance of the block.

You acheive this same effect in blender by creating a group in a seperate blend file and then instancing it in your scene.
It's not always convenient to have a file link between a group definition and an instance of the group, so what I've generally done is assign my grouped objects to a layer that's turned off or create them in a new scene and then use instances everywhere in the layout scene.

Many thanks for that, @JohnBurrill - great explanation of what is going on and limitations! I managed to solve my problem by creating a separate scene just for the group master alone, and centering it there... Cheers!


text:
Faces glitch when texture paint
When I texture paint I found some faces that changed color. It's like related faces-what I paint on one face duplicated on another. I already cut my model with seams for better grid. But I have overlapping because of related points.
On this screenshot you can see that if I select one point on my mesh its several points on UV. How to fix it?

I still can't realised how to make a one point from this several points in UV. My steps: Unwrap by smart uv project, check overlapping and fix them. but when I try to move them on UV map 3 or 4 point move together. What do I do wrong?

this is my file

"But I have overlapping because of related points. " I wonder what that means. Anyway, just make a UV map that does not have overlapping UVs - it's as simple as that. UV Islands should have some gaps between them as well.

Hello, it's not clear what is your problem, if you mean that the faces are overlapping, it won't be good for your painting, you need to make sure that it's not the case, by the way if the goal is to paint your object in the 3D view, you don't have to use seams, you can simply unwrap with a Smart UV Project.

Oh all right thanks I'll change it. Sorry for stupidity

sorry I still can't get it. I edit my question and added a blend file

Your UV islands are too close to each other, the color bleeds onto the adacent island, to fix that unwrap again and in the Operator Box increase the Island Margin to something like  0.001:

No, it doesn't work. With Island Margin 0.001 or 0.03 points still related somehow

Thank you very much for help. I fixed it. It was this "UV Sync Selection" bottom

what do you mean, not sure how the the Sync button fixed your problem?


text:
Boolean modifier doesn't work well
I want to make some patterns on this object (pants)

But after hiding the curves not all of them leave marks

How can I fix it?
This is my blend file

Could you share just the relevant objects in a stripped-down file on https://blend-exchange.com/ ? There are a few possible causes, and we can't just guess.

Please share a Blend file which just includes the pants and objects you have used for the boolean modifiers.  You can share it via https://blend-exchange.com/ following the instructions there to copy the full link on that page. Then edit your question here and paste the link into it.

Have you tried setting the Solver from Exact to Fast in the Boolean modifier?

Yes, I've tried change the Solver. I just added a blend file

File the holes of these cylinders, your objects need to be manifold:

Also the scale of your object is bad, apply it to bring it back to 1/1/1 (CtrlA) then in Edit mode select all and recalculate the normals (ShiftN):

At last activate the Hole Tolerant option of the Boolean:

Thank you very much for your time! It helps me.


text:
cloth physics clipping?
I have been working on physics for a skirt for a number of hours but I keep encountering the same issue seen in the video attached
https://imgur.com/a/Ra8p26F
I have object collision to 20 and self collision to 12, the distance settings between the collision and cloth object are the lowest they can be, and the mesh is paper thin so nothing should be overlapping. My only other thought is that this is an issue with the mesh itself and I would need to remesh the skirt to try and get a realistic result - what're your guys' thoughts? Any help would be appreciate because at this point I am just throwing myself at a wall lol.

Hello please share your file (remove the parts that are useless): https://blend-exchange.com/

Here is the link:

It probably has to do with the topology, the faces are overlapping (see the image below), also don't forget to apply the scale. Maybe try this solution instead: use a larger and simpler object that will be your cage, make it invisible, give it a Cloth simulation, and give to your skirt a Mesh Deform modifier with this cage as Object.


text:
How to make a 45degree oblique cut
I have some uni project where we have to make these oblique cuts on different objects, and it would be amazing if I could double check my results with a 3D model.
So the goal is to apply this logic to more complex objects too (Pics for it to make sense)
Its almost like a bevel, but trough the whole object

I'd investigate using a Boolean Modifier for that.

Using the Boolean Modifier as @John Eason said in his comment, you could use a mesh plane rotated and located as needed for the cutter.
I have made an object similar to the image showing Fig 11i. Note that the axes I use may differ from your object's orientation.
Add a mesh plane, Using Global Transformation Orientation rotate it on the X axis 45 degrees:

Then rotate the plane on the Y axis 45 degrees. Press Ctrl->A and apply rotation:

Move the plane on the Y axis to the location required:

With the object selected add a Boolean Modifier. Either click in the Object box and select the plane, or use the eyedropper and click it on the plane in the viewport. Select the Fast option:

Result after applying the Modifier:

amazing! Thats exactly what I needed! Thank you a lot:)


text:
Improve speed of creating keyframes
See edit below.
We are looking to visualize scientific data in Blender as animation tracks. The data on every frame is important, including even small fluctuations, so interpolating between keyframes is not an option.
Currently, we use a Python script in Blender to load the data and loop through it, adding a separate keyframe for every animation frame (30 fps), but this seems to quickly overload Blender's animation system, requiring 12 seconds for a 1 minute recording of data. This is just test data. Recordings upwards of 20-30 minutes will be normal.
We had started making a custom visualization pipeline, but we cannot maintain that, so the power and versatility of Blender will be needed.
I looked into a hack way of putting the data in a motion capture file and then importing that, but this will be too awkward going forward, I think.
So my question: is there any reasonable way to do frame-by-frame animations in Blender?
EDIT:
Based on the helpful comments from @TheLabCat, @Robin Betts, and @Alexandre Marcati, I made a minimal example that runs >10x faster and works as expected.
Keyframe interpolation mode was changed to "CONSTANT".
The important changes were:

Make sure Animation Data is first cleared whenever re-running the script.
Create new F-curves for an Action attribute of the Animation Data.
Add empty Keyframe Points to the F-Curve with "fcurve.keyframe_points.add()"
Insert the data into each Keyframe by setting the "keyframe_points[frame_num].co_ui" attribute of each animation channel corresponding to a given F-Curve.

Here is the data:
https://gist.github.com/rennis250/585b1d6efaeedf08441260aa5a7b0619
Here is the code:
import os
import bpy
import mathutils

from mathutils import Vector
from itertools import chain

import numpy as np
import pandas as pd

class AnimateData():
    def __init__(self):
        self.poses_df = pd.read_csv(os.path.join('./aligned_poses.csv'))

        self.init_ori = mathutils.Quaternion((0.0, 0.0, 0.1, -0.995))
        self.obj = bpy.context.scene.objects['Obj1']
        self.obj_curves = {}

    def init_fcurves(self):
        if self.obj.animation_data is not None:
            self.obj.animation_data_clear()

        self.obj.animation_data_create()
        self.obj.animation_data.action = bpy.data.actions.new(self.obj.name + 'Action')

        loc_fcurves = [self.obj.animation_data.action.fcurves.new('location', index=index) for index in range(3)]
        rot_fcurves = [self.obj.animation_data.action.fcurves.new('rotation_quaternion', index=index) for index in range(4)]
        scale_fcurves = [self.obj.animation_data.action.fcurves.new('scale', index=index) for index in range(3)]

        for fcurve in chain(loc_fcurves, rot_fcurves, scale_fcurves):
            fcurve.keyframe_points.add(len(self.poses_df))
            for i in range(len(self.poses_df)):
                fcurve.keyframe_points[i].interpolation = 'CONSTANT'

        self.obj_curves[self.obj.name] = ({
            'location': loc_fcurves,
            'rotation': rot_fcurves,
            'scale': scale_fcurves,
        })

    def execute(self):
        self.init_fcurves()

        for frame_num in range(len(self.poses_df)):
            bpy.context.scene.frame_set(frame_num)

            x = self.poses_df["translation_x"][frame_num]
            y = self.poses_df["translation_y"][frame_num]
            z = self.poses_df["translation_z"][frame_num]

            # convert to blender coords
            coordinates = [x, z, -1.0*y]

            rot_x = self.poses_df["rotation_x"][frame_num]
            rot_y = self.poses_df["rotation_y"][frame_num]
            rot_z = self.poses_df["rotation_z"][frame_num]
            rot_w = self.poses_df["rotation_w"][frame_num]

            # convert to blender coords
            curr_quat = mathutils.Quaternion((rot_w, rot_x, rot_z, -1.0*rot_y))

            # original approach, was slow, now faster
            #
            # self.obj.location = coordinates
            # self.obj.keyframe_insert(data_path="location", index=-1, frame=frame_num)
            # self.obj.rotation_quaternion = curr_quat @ self.init_ori
            # self.obj.keyframe_insert(data_path="rotation_quaternion", index=-1, frame=frame_num)
            # self.obj.scale = [0.001, 0.001, 0.001]
            # self.obj.keyframe_insert(data_path="scale", index=-1, frame=frame_num)

            # alternative approach, even faster and same visual results as above
            #
            obj_fcurves = self.obj_curves[self.obj.name]
            obj_fcurves['location'][0].keyframe_points[frame_num].co_ui = [frame_num, coordinates[0]]
            obj_fcurves['location'][1].keyframe_points[frame_num].co_ui = [frame_num, coordinates[1]]
            obj_fcurves['location'][2].keyframe_points[frame_num].co_ui = [frame_num, coordinates[2]]

            rot = curr_quat @ self.init_ori
            obj_fcurves['rotation'][0].keyframe_points[frame_num].co_ui = [frame_num, rot[0]]
            obj_fcurves['rotation'][1].keyframe_points[frame_num].co_ui = [frame_num, rot[1]]
            obj_fcurves['rotation'][2].keyframe_points[frame_num].co_ui = [frame_num, rot[2]]
            obj_fcurves['rotation'][3].keyframe_points[frame_num].co_ui = [frame_num, rot[3]]

            obj_fcurves['scale'][0].keyframe_points[frame_num].co_ui = [frame_num, 0.001]
            obj_fcurves['scale'][1].keyframe_points[frame_num].co_ui = [frame_num, 0.001]
            obj_fcurves['scale'][2].keyframe_points[frame_num].co_ui = [frame_num, 0.001]

anim_data_obj = AnimateData()
anim_data_obj.execute()

The title of the question doesn’t really reflect the actual problem very well, unless you are asking two questions in one, which you generally want to avoid. Are you asking how to change the interpolation to something like linear or constant instead of B-spline, or is that taken care of?

How many animation channels are you adding per frame? I’ve done per-frame animation of 8 or so at a time for a music visualizer, and Blender was done almost instantaneously, so I suspect poor code.

I'll try to come up with a better title. My apologies.
Thanks!
I would prefer no interpolation. The animation runs at 30 fps and there are 30 keyframes per second. Rather than say, 3 interpolated keyframes at frames 0, 10, and 29.
We have 6 objects, some of which rotate/scale and some of which don't. Total animation channels per frame is 37.
I used keyframe_insert. Profiling shows that this is where performance drops. I've learned about obj.animation_data.action.fcurves.new and using that interface is about 10x faster, but transform values get locked to 0.
I will update my question.

Right, I’ll go look at my script. Meanwhile, constant interpolation is about as close to “off” as you’re going to get: A channel stays at a value until it arrives at a new keyframe. That really should be a separate question, but here you go.

Would a sample chunk of input file, help, here, for folks to test approaches?

I'm using a keyframe_insert method as well. What system are you running this on? Can I have a look at your Python code, and as @RobinBetts suggested, a sample of the input data?

Thanks both! I will trim the code down to a minimal example and provide data. Will take me a few minutes.

After a brief test, rendering those 8 channels for a 5 minute audio file took a few seconds, so, I think the times line up.You can do things to make the UI update during a script run, I think, and even add a progress bar. I'll look into that.

In making the minimal example, I think you helped me realize the issue. It now runs much faster and works as expected. I will update the question above with the code + data sample.

... a summary answer from one of you, when the time comes, even if the  problem is solved (or just ameliorated) in the commentary, would be great.

For having no interpolation between keyframes you should set the interpolation mode of the keyframes to "constant" (that means the value will stay constant until it gets to the next keyframe). Not sure how to set that through code, but shouldn't be very complicated.

Summary answer:
Previously, I was blindly using keyframe_insert on objects to add animation data to each F-Curve channel (e.g., x/y/z location). This was inefficient. I wrongly assumed Blender must interpolate between a handful of keyframes, which would have conflicted with our animation intentions.
Solution (see code above):
(1) Clear Animation data when starting the script
(2) Create new F-curves for an Action attribute
(3) Add empty Keyframe Points with fcurve.keyframe_points.add()
(4) Insert the data into each Keyframe by setting the "keyframe_points[frame_num].co_ui" attribute


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mesh not moving with armature (using rigify)
I am a beginner using Blender for the first time. I have been trying for the past 2 days to get a mesh to move following an armature, but haven't succeeded yet.
I am using Rigify, and my ultimate goal is to export this model to Unity.
I have tried setting the mesh as a child of the armature using the "Armature Deform" and "Automatic Weights" options, but the mesh is not moving with the armature. The mesh is one that I downloaded from the internet. I tried with different kinds of clothing object, but it fails all the time.
Any advice or suggestions would be really appreciated. You can check out my Blender project file at the link below:
https://drive.google.com/file/d/1XSATqLbBKmFBakbcgGDgnMiSGWzlXltB/view?usp=sharing
Thank you in advance for your help!

Your mesh appears to be just a T-shirt and has a ridiculously high number of vertices (around 677,000) so there's no way that rigify can cope with that. The armature itself also has odd extra bones in it so I'm not sure where that came from?


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How do I combine 2 shaders so that only one principled bsdf shader is connected to the material output?

Hello everyone, blender noob here.
I have 2 shaders, both of which are connected to a mix shader, which is then connected to the material output. While this works fine and gives me the results I want, I would like to re-arrange the shaders in such a way that only one of the principled BSDF nodes (that is, the node with inputs into its Normal and Base Color) is connected to the material output.I would like the same result on the material, but I have found it quite confusing to do so (and frankly I'm not sure if that way of re-arranging the shaders while keeping the original result is possible).
I've included a picture of my node setup.
I've tried connecting the principled BSDF node at the top and the color ramp (with the blue gradient, underneath the image texture) to the shader inputs of a mix shader, and then connected the image texture's alpha to the mix shader's fac. I then connected this mix shader to the base color of the bottom principled BSDF shader. After that, I removed deleted the mix shader connecting to the material output and connected the bottom principled BSDF shader to the material output. However, this didn't give me the result I wanted.
Is there a different way to achieve having only one principled BSDF shader connected to the material output, while also keeping the material looking the same? Or is it not possible?
If there are also any additional criticism concerning anything else about my setup, please do let me know. thank you in advance!

First, why do you want to do that? Second, you could try mixing the inputs instead ie. mix(Principled(a1,a2,...), Principled(b1,b2,...),f) becomes Principled(mix(a1,b1,f),mix(a2,b2,f),...). But I don't think this will give the same output except in very simple cases.

I'm trying to bake this material, but for some reason some things weren't being baked properly (like the metallic of the bottom principled shader). I saw from another post that it baked properly when there is only one principled shader plugged into the material output, so that's why I was wondering if that was possible with my material.  Also, my apologies, but I'm not able to follow exactly what you mean. Is there perhaps an example that you could direct me to?

@user18074777 Basically you can use the image which you are using as mix factor for the Mix Shader node, instead use it before the Principled BSDF to mix all values in which they are varying. Only that instead of a single node for mixing you'll then need more, one for mixing colors, one for mixing roughness values etc. and plug those mix results in the appropriate inputs on the Principled BSDF.

@GordonBrinkmann this makes sense, thank you! I did as you said, and this worked for me.


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Unable to select multiple objects
So I’m not sure what is going on, but I am unable to select more than one object. The first object is select is orange and then any following that is blue. I am in object mode. I tried selecting multiple in the outliner, but the same thing happened. I am trying to turn these wireframe objects back into solid objects, but it will only do it for the orange highlighted one that I selected first.
Also, while trying to fix this problem, I somehow created a display of XYZ axis for each individual object which I have no idea how to turn off.

Uncheck 'Affect only Origins' for starters! You're also in Material Preview mode rather than Solid view (top right of the toolbar). I'd suggest you share your Blend file so that we can see what else you've changed.  You can share it via https://blend-exchange.com/ following the instructions there to copy the link on that page. Then edit your question here and paste the link into it.

Thank you! I appreciate the help.

The issue with the colors is that you've selected a non-default theme "Deep Grey" where the active object is yellow but non-active selected objects are blue.  To change this back, select Edit → Preferences... from the menu, select the "Themes" panel from the list on the left, and at the top of that panel, click on the "Deep Grey" preset and change it back to "Blender Dark".
It looks like you already figured out how to get rid of the axis annotation by unchecking the "Affect Only → Origins" option, as @JohnEason had suggested.
The remaining problem is that, when multiple objects are selected, switching the viewport display from wireframe back to textured only affects the active object by default, not all selected objects, but you can change this behavior by holding down the Alt key at just the right time.
So, select all the objects in your truck that you want to change back to solid objects, open the "Object Properties" panel in the properties pane, open up the "Viewport Display", and while holding Alt, click the "Wire" selecting in the "Display As" dropdown and change it to "Textured" (the normal default).  That should fix the issue.
Technically, as long as you're holding Alt either when you click on "Wire" to change it or when you select "Textured", all selected objects will be affected by the change, but you can just hold down Alt the whole time to be safe.

To add to that, you can select all the objects at once in the viewport by dragging the mouse over them with the left button down.

Thank you! I was losing my mind. I thought I had really messed something up.


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How can I move (attach) one object to another exactly without doing it manually?
I have two hexagons, I want the side of one to exactly coincide with the side of the second. Doing it with your hands is crooked and inconvenient. Is it possible to somehow move one to the other in a blender by selecting the sides of the connection. I can't find on the Internet how to do this, some of the suggestions are connections by stretching one to another, but I need to save the shapes of all the polygons. An example of what I want to achieve is manually applied

Search for snapping.

To generate many objects side by side from a single one use an array modifier

The thing you need is called "Snapping"
It was hugely improved in Blender 4.0
So I recommend you to use 4+ versions of Blender
Here is one-minute video explaining the Snapping: =link=

One thing this video is missing:
Before snap things you should choose your Snapping Mode
(it's next right to the Magnet icon on top of the screen)
Here:

If you want to snap vertices and edges – click Closest, click Vertex,
and shift+click Edge Center
In this case click is used to choose a single option, while shift+click adds/excludes another options.
Same by using click and shift+click choose things you want to be affected by snapping:
Move/Rotate/Scale
Then just snap things like it was shown in the video above.

P.S.
Since you struggle with very basic Blender things - I recommend you to learn Blender's basics first. And only after to model things in Blender.
Such approach will preserve you from TONS of suffering.
I highly recommend you a comprehensive video-course named "Complete Blender Creator" (link)
Though you can use any other course of your choice.

P.P.S.
Note that YouTube is great to enhance your Blender knowledge but not to build it from scratch.

Good luck on your Blender Journey ❤


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i want deform this metal strip by using this bending machine
I want deform this metal strip by using this bending machine. Which physics should I use soft body ? rigid body ? and what is method to use related physics? I applied rigid body and soft body physics but its not working what I want.

I don't know if you can do it correctly with physics, maybe simply use an armature to bend your object?

yes i know physics rules you can just tell me.. how to do it using physics

By using armature object does not bend in uniform way. i mean i does not become proper " L " shape.

You can make it look sharper, you just need to have the proper topology


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How can I select objects in collection to be visible with Geometry Nodes?
I want to create expressions set to make animations, but I want to swap between them easily with Geometry Nodes or any other add-on available, any idea? Thanks in advance.

Could you provide your Blender file using https://blend-exchange.com/ ?

Yes, already did it

You should be able to put the objects for the two expressions into two separate collections (e.g., "Eyes Open" and "Eyes Closed"), hide both those collections, and then use geometry nodes to select the desired collection to replace the "Face_Sets" geometry.  The setup would look like this:

Here's an updated Blend file.

Edit:
To ease animation, a Switch node can be used for two expressions. For more than two, an Index Switch node should be considered:

I took the liberty to edit your answer instead of writing a new one as mine is merely a slight variation from yours. Feel free to remove it if it bothers you.

Thanks you both, with this I´ll be able to do the animations that Im looking for!

@EdgarMontesdeOca: May I recommend to apply this : What should I do when someone answers my question?


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Blender texture distorted inside quad but correct at edges
Has anyone seen this effect before? I made polar UV coordinates for the ring and applied the standard brick texture. The polar coordinates basically take a square in UV space and squash it onto a trapezoidal face. I would have expected linear interpolation throughout the face, but something odd happens near the middle. In the top left quadrant, I used ctrl-r to split the faces and line up the split edges with the texture lines. That straightens them out, so I'm sure the linear calculation is correct along all the face edges.
After taking the picture, I tried splitting a distorted quad along the diagonal, switching between fixed and fixed-alternate. It turns out, one of the split directions matches the distortion, and the other direction distorts the other way. So behind the scenes, quads are made into triangles for the UV mapping.
Unless there is a different UV calculation mode for blender, I think the only fix is to split the trapezoids radially.

Hello and welcome to BSE. Can you share a simple example blend https://blend-exchange.com

Attached a blend file with a single quad showing the behavior. Try splitting the quad vertically with ctrl-r. then undo that and use ctrl-t to split on diagonal and swtich the diagonals back and forth.

Your node setup is wrong.
It's easy to fix :

* because for a generated texture (Mapping) Vector also should be set to Generated

No, the generated texture coordinates would end up with no distortion. The point here was to introduce distortion by moving the quad vertices. But each half of the quad is apparently calculated separately, so you see the texture being sheared in each triangle, but they don't match at the diagonal line.

@DHughes — Be informed: I do not make guesses. I've figured out the solution investigating your test file.  — So, please, just try to do the thing I've suggested in my answer. — After that tell me: weather it worked as good as it did with a test file, or did it not. — Ok?

Nope, did not fix it. If you load my demo blend and try your suggestion, you will see the bricks at the bottom are the same size as the bricks at the top. They need to be smaller (same count at bottom as at top).


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Shrink/fatten does not work

Here I am using a boolean on my subject with two cylinders and then duplicating the cylinders and shrinking them, one is working but the other one is not.

Hello, are you sure that this is a linked duplication? (Alt D)

I'm not sure what the OP means. Maybe they should describe the problem more in detail?

We do need more information, here.. what is the relationship of the 2 cylinders (instances? Part of one object?) perhaps a share on https://blend-exchange.com/ would save unnecessary discussion of details.

Robin Betts,  i make a cylinder and then use array modifier so both cylinder should part of one i guess

You have 2 different boolean objects here: Cylinder, which is only seen as a Bound box, and Cylinder.001 that you see as Solid. The object that is booleaned doesn't use Cylinder.001 as boolean object, so you can edit it as much as you want, it won't change the shapes of the wholes.

but i cant shrink cylinder 1 that i can see as solid . can you please try to shrink the cylinder one and make small you can see the problem i hope

it works for me, it reduces the size of the cylinder and the arrayed cylinders, for a cylinder shrink/fatten won't be different than scale


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Cannot bevel an object

The bevel doesn't work properly on these edges.

Hello, maybe bad topology? Could you please share your file?

Please share.. this could be, for example, hidden duplicate vertices or somesuch,.. a share will quickly nail it.

How can i share the file here iam new in it please help

blend-exchange.com

I uploaded the file. How to know you guys got it or not ?? please response if you got this file

Hi, nurul, If you follow the instructions on https://blend-exchange.com/ , the original question-link you pasted in the  text-box will be converted into an image-link to your upload, which you can then edit into your question.

Thank you Robin. I uploaded it successfully. Now please review it and help me to solve the problem. Thank you

Apply the scale in Object mode (otherwise the bevel will be deformed on some axis), select all in Edit mode and M > Merge by Distance to merge the overlapping vertices (otherwise the bevel will be bad) and at last create these edges to avoid the ngon, and the bevel should work fine:


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Bone won't show up in vertex group
I recently followed this tutorial series and I am currently rigging using rigify. When I got to the tongue rigging part with automatic weight paint my tongue was influenced by other bones around it. I have tried to fix this by manually removing the weight through the vertex group but some bones aren't showing up. I have tried to add the bone to the vertex group but it still didn't work. I've read somewhere that some bones need first to be deformed in the bone property tab, I tried that and it still didn't work. I try to only automatically weight paint the tongue and the bone I want by only selecting them when parenting and somehow other bones still influence the tongue. This has been driven me crazy the past few days now please help.
Also, how do I share files on this site?

You can share your Blend file via https://blend-exchange.com/ following the instructions there to copy the link on that page. Then edit your question here and paste the link into it. Your Blend file must be under 30 Meg in size for that site so remove any unnecessary objects first if it's larger.


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How do I Automatic Weigh paint to only the selected bone
I'm following a rigging tutorial and the person automatic weight paint the tongue to a rigify rig with no problem, but when I try to do it the tongue is influenced by other bones. I try to fix it through the vertex group but some of the bones are not showing. So I'm trying to auto weight paint the tongue to only the tongue bones.
Please help
Here is the file
https://drive.google.com/file/d/1d-KzTd30FuHp7l-3l2z1unicDz4j466u/view?usp=sharing

You do have only the tongue bones selected, yes?

Maybe select the vertices of the tongue and go into the dropdown panel on the right of the vertex groups list and Remove from All Groups? Then assign to the correct vertex groups?

I've already tried those but it still didn't work


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Using 8192 samples and denoising (0.05 threshold) and still get noisy/blotchy renders in the shadows
It's in a night scene at 4K resolution, on a terrace lit by wall fixtures and an night hdri.
I see people putting 1000 samples max and get clean results. How can I have 8192 samples with denoise and still get blotchy/artifacted/noisy shadows?
Can you help understand how to get rid of the noise?
Thank you in advance.


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How to make a bubbly shaped smoke mesh quickly?
What's the best approach for this kind of mesh? I know I can just bunch spheres together and boolean them but I'm wondering if there's a better way with geo nodes or something. I've googled this and only thing that came up is using voronoi as displacement but it's not close to the look I want. Someone in blender discord also suggested metaballs but I can't achieve the same corner shape with it. I'm looking to use this mesh in UE5 niagara for an explosion fx.

Are you intending to animate it like your second image above?? I might have a look at simulation nodes or particle nodes, using simple spheres as the instance. You can get some nice stylized smoke plumes that way.

https://blender.stackexchange.com/questions/194011/is-there-any-technique-to-give-a-metaball-effect-to-the-particles-emitting-from/ https://blender.stackexchange.com/questions/265925/how-can-i-combine-three-spheres-properly/ https://blender.stackexchange.com/questions/244655/whats-the-most-fun-way-to-make-a-snowman-in-blender-%ef%b8%8e%ef%b8%8e%ef%b8%8e/244710#244710

Metaballs was indeed the answer and I'm just a big bakasussy.


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How do I apply multiple selection criteria to a single node?
I'm looking to select the centre point of a face. I've been able to identify using the below that if I filter the selection to the 'dirt' material, and then select the first (0 index) point it is the one I am looking for. However, I have realised I don't actually want the 'points to vertices' conversion node that I am using as the entry point for the second 'selection' filter. Is there a node I can use that will allow me to filter the points from the 'mesh to points' node or will I need to do something silly like convert to vertices and then convert back to points? I also considered some sort of 'add' for the selection inputs, but I do need them to chain, i.e. select dirt first, THEN select the first index.
Long time viewer first time poster, I apologise if my question does not make sense or is very basic. Thank you for your time!

This is what my node tree looks like now

And this is what I'm after. Or is this essentially what I already have?
EDIT (2): Removed the extra about the end goal as I think this was confusing some people and added an image of what I want the nodes to look like
EDIT (3): Thank you Markus! The 'Delete Geometry' node was exactly what I was looking for!
I needed to use the 'selection' component twice in a row- I wanted to select the 0 index OF the selection of the material, like so:

tbh i don't get what you want. Where is the dirt in your picture? Maybe i am too blind/silly, but i don't see it. And so i don't know where the leaves should rotate to. Maybe a "before" and "after" image with "after" is what you want to achieve would help? but i am 99% sure that you don't have to make these conversions and that there are easier/better solutions.

Sorry, I do not know what you are actually asking. What kind of multiple criteria? And you say you want to select the center point of that certain face and you have identified it. Well what is left to do then? And even without selecting the material, if this is a single geometry (since all geometry comes from the Group Input), each point has its individual index so the only thing you need to find is the index of that specific point.

If you want to get only the first point (index = 0) then simply delete all other points:

Keep in mind the "Greater Than" node is not needed here, as indices are never negative, and any non-zero integer will implicitly convert to TRUE boolean.


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Sound triggers when particles collide with plane/object
I'm looking for a way how to activate a sound when a particle collides with another object in Blender.
In this case, I would like to know how to do this with a particle and a plane.
The scene is something like this

I'm using two planes: one as a particle emitter, which is being rendered as raindrops; and another as a collider with a dynamic paint modifier (canvas). The raindrops fall one by one at different intervals. I want a sound to be played when each raindrop hits the collider. The particle emitter and the X/Y/Z axes are controlled by OSC via Touchdesigner. I'm using JPfeP/AddRoutes to communicate between the softwares. I want to send a trigger from Blender to Touchdesigner when each particle hits the ground to play a sample. Alternatively the sound can also be played inside blender.
The OSC message struture for Touchdesigner, that can be sent via a plugin, or by script must have:
IP Address: of the machine running Touchdesigner.
Port Number: The port number which is listening
Address Pattern: A string that identifies the specific action or event, e.g. "/collision".
Arguments: for triggering a sound, this might simply be a numeric value (e.g. 1 or 0) or a string indicating the event.
Example of OSC Message
Address Pattern: "/collision"
Argument: 1 (indicating a collision event)

I'm using two planes: one as a particle emitter, which is being rendered as raindrops; and another as a collider with a dynamic paint modifier (canvas).
The raindrops fall one by one at different intervals. I want a sound to be played when each raindrop hits the collider.
The particle emitter and the X/Y/Z axes are controlled by OSC via Touchdesigner. I'm using JPfeP/AddRoutes to communicate between the softwares.
I want to send a trigger from Blender to Touchdesigner when each particle hits the ground to play a sample.
Please let me know if more information is needed.
Thanks.

Please edit your question and add your comment into that rather than adding extra information as a comment which people might not see. Also we can't really help with sending triggers to external software as we have no idea what "Touchdesigner" might be expecting!

The sound can also be triggered in blender, touchdesigner is only an option. Is the same osc data blender expects.


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Problem With Loop Cuts and Hooks
So I am following a tutorial to make a fluid parachute. The ropes are hooked to the parachute and an empty that is placed inside a box. When I play the animation, it works fine. However, the tutorial says to add loop cuts to the rope to make it's movement more realistic. However, when I play the animation after adding the loop cuts, the rope does not follow the empty properly. The hook is still connected, but it just extends the end of the rope down in a straight line.
The tutorial: https://www.youtube.com/watch?v=5HRIG04a4X0&t=1s

Hi. You haven't added the Cloth simulation yet. So, without it, that's normal behavior. The Empty pulls down the first few vertices that are hooked. All other vertices stay where they are. In consequence, only the faces at the end of the rope get stretched a lot to follow the Empty. The rope's end seems to get longer and longer. -- The solution is to simply continue the tutorial ;-) Create the Pin vertex group, add the Cloth modifier, and enter the pin group in the settings. The pinned vertices are not affected by the cloth sim and can be animated by the Rigid Body physics & hooks.

I did follow along, but the bottom pin still stretches out even after the cloth simulator is added.

Oh sorry, that's because you have 8 duplicated vertices. It stops the cloth simulation. Have a look here: https://blender.stackexchange.com/q/182090/107598. Additionally, you should move down the sphere empty to the end of the rope so it does not pull up this end. Finally, hook all vertices of the circle at the end of the rope. (You have only hooked 3). The vertices must be hooked and pinned. There are the Select and Assign buttons in the Hook modifier and in the Vertex Group settings so you can check & fix it. Don't forget to deselect everything with Alt+A or 2x key A for the check

I'm not sure how, but it is still causing problems. I followed along with what you recommended.


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I can`t get the Mesh Deform Modifier To work
I'm currently working on a project for a university. I use the Mesh Deform Modifier to simulate some kind of car destruction. I can see the changes in a viewport, but when I try to render an image it never shows.

↑Viewport shading image.

Rendered image, as you can see, some parts of a car (such as doors, hood, etc.) are actually affected by Mesh Deform Modifier, but not the car body.
To simplify.

↑ Red Car Body modifiers

↑ Red Car Deform Body modifiers

↑ Blue Car Body modifiers

↑ BlueCar Deform Body modifiers

↑ Black and blue car that deforms the way I want it to.
I've tried a ton of options, read a lot of similar topics, but I haven't found a solution yet.


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Why does my normal map have yellow values
I'm trying to figure out how to bake normal maps (beginner to Blender and 3d modeling). I made this high-poly and low-poly version of ramen bowls based on this post.
The process I'm following for baking is as follows

UV unwrap the low-poly model
Make sure the two models are overlapped
Render Engine → Cycles
Baking Type → Normal, Space → Tangent, Selected to Active

However, the resulting normal map has these yellow values. It looks like this usually means the normals are reversed? I tried to check the face orientation of my models but didn't see any red faces indicating so. The render tab also shows the low-poly bowl as having this black color

Not sure if it's because my low-poly model is kind of poking out of the high-poly one?

I tried to use a Cage object as some other posts have suggested. But that didn't really do anything. Would appreciate any help!
Edit: Here is my updated blend file

Hello, you may need to increase the Extrusion value a bit, but maybe share your file? https://blend-exchange.com

I would recommend reading and learning everything these two posts 1 2. For help understanding issues when baking normal maps.

So from my understanding of the posts, the main reason the normal map is coming out weird is due to geometry? Specifically, my low-poly bowl's curvature is very different from the high-poly one, so it'll be very hard to match unless I add more geometry. In terms of solution, I'm thinking of adding more loop cuts to basically make the curvature match closer to the high-poly ver. Is that the right way to go? Also, I see I have normals that are 90 deg to each other, would adding bevels help? https://imgur.com/a/SCjSDgk

I can't see the high-poly in the file you share

@moonboots it's the object named Bowl in the hierarchy https://imgur.com/a/XnQEaPM

@Jakemoyo so I tried to add more geometry to make the low-poly less boxy in a way (the curves on the top rim really stands out currently) and to help get a better normal map bake. I added bevels, and adjusted my seams so the UV unwrapping is better. The result looks a little nicer, but I want to smooth out the rim further. I'm thinking of adding loop cuts, but not sure how to proceed from there. Do you have any advice here? https://imgur.com/a/eIvG5HT

@moonboots just updated the blend file. High-poly should still be the Bowl object, lmk if you still can't see it!

ok but Bowl doesn't have any detail to bake so I'm not sure why you are trying to bake it?

I think this actually answers one of my questions, namely do I even need to bake. I was assuming that it’ll magically transform a low-poly and make it look like a high-poly, but I guess that’s not the case. One thing I was confused by was this low-poly bowl asset I was using (from the Unity store), has only about 460 tris, but they have a normal map, ao map, and rgh that made the asset look really good in Unity (even tho it’s just a plain white bowl). Do you know how they achieved it? https://assetstore.unity.com/packages/3d/props/interior/plates-bowls-mugs-pack-146682

I don't know but we can clearly see the angles, the bowls are not very smooth, but yes you can't make the silhouette of low-poly look high-poly with a normal map, a normal map will just add details


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Blender Rigging Weightpaint Not Working
I am working on a model megalodon shark for a animation project but can't rig the model. I have been trying to fix it for about a month but its not worked.
When I tried to use automatic weightpainting on my models rig it didn't work so I attempted to manually weightpaint on the model however when I finished and tried to move the rig it all became stretched. You can see that where I weightpainted and where I move the rig it doesn't smooth out to the rest of the model.
I can't add the file as it is way to large, the subdivision surface modifier has been applied as that's what the tutorial showed.
I have been following Critical Giant's guide on making a Trex.
Any help will be greatly appreciated, thankyou and enjoy the rest of your day.

hello please share your file, i suspect you have too many vertices, also put the Armature modifier above the Subdivision Surface modifier?

Rigging can be tough. Here are a few quick tips to help:
Check Mesh: Ensure no overlapping vertices or disconnected parts.
Recalculate Normals: In Edit Mode, select all A and press Shift+N.
Automatic Weights: Ensure bones are correctly placed and scaled. Simplify the mesh if needed.
Manual Weight Paint: Use larger brushes first, then refine. Use the Blur tool for smooth transitions.
Bone Envelopes: Enable Envelope in the Armature modifier and adjust bone radii.
Modifier Order: Ensure the Armature modifier is above Subdivision Surface in the stack.
Normalize Weights: Use Normalize All to fix weight issues.


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Shape Key not working correctly in GLTF export
I've got a character imported into blender via the Character Creator importer (https://github.com/soupday/cc_blender_tools/releases/tag/2_0_9). Everything works fine in blender when changing the values:

but once exported to GLTF the results are different.

Any idea what might be happening? If I uncheck the 'Shape Keys Drive Jaw Bone' and import my character, the mouth shapes seem to break in the same way the GLTF export does. My blender knowledge is very rusty so hoping it might be something simple! Feels like I need to somehow preserve the link between the bone and the blendshape?
Update: The same issue happens when exporting FBX and importing in Unity and trying to adjust the blend shapes.


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Volumes with space-dependent light intensity
I would like to use Blender to render pictures of atomic orbitals like in the following picture

or like in this video. This seems to need some light-emitting volume whose intensity is described by some formulas.
Which would be the smartest approach for this problem?

You can use an Emission shader for the Volume socket of your Material output node, and give it a volumetric texture.
It's pretty easy for a 1s orbital, (n,l,m) = (1,0,0). (spherical symmetry, monotonic decay: it's not actually exponential in my example below):

Create a sphere, and assign a material to it like the one in the picture.

The first three nodes to the left (Geometry, Object Info and Vector Math>Subtract) will output a vector (x-x₀, y-y₀, z-z₀) for each x,y,z point in the sphere's volume, where x₀,y₀,z₀ is the pivot point of the sphere. The following node Vector Mapping can be used to scale the texture. These are the cartesian coordinates that will be used to define a scalar function, like a wavefunction.
The last four nodes to the right ("Math>Absolute, Color Ramp, Emission, Material output) will take the output of your scalar function and assign it to the volumetric emission, colored according to a color map (I've taken the absolute value, you might want to take the 2nd power, or to have different colors for the positive and negative values).
In the middle, you will need your actual scalar function. It can be any node, or group of nodes, that takes a Vector (blue socket) as input, and outputs a scalar (grey socket). In my example, I've used a Gradient texture node. Unfortunately, complex functions are not built-in in blender. You can, however, create a Script node that implements the wavefunctions (you will probably need numpy.polynomial.legendre)*

* I've never done this before, so I can't guarantee it's possible to just make python do the math. If it's possible, I think this wiki page is a good starting point.

I have little experience in creating custom nodes in Blender, so I haven't given details on that. I can't seem to find much about the Node class (I don't want to create an OSL node, just a python node). If I have some spare time later, I'll try to integrate that part of the answer.

Excellent, this is just what I needed! Thank you very much

Here you may see a finished example http://tungsteno.io/post/vis-hydrogen_wavefunction_111/ together with the script generating this video https://github.com/TungstenHub/tngt-blender/blob/master/scripts/orb11.py Thanks again!!