text:
Simulating points moving along curves
I'm trying to create a system of points moving along curves.
In the first step, a single curve is duplicated into a track of 6 parallel curves with these geometry nodes:

Then I'm using the simulation zone to move the points:

But I can't get it to work the way I want it to. My best attempt looks like it creates new points along the curves instead of creating them at the beginning and moving them.

While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues.

By "points moving along curves" do you mean something like this? https://blender.stackexchange.com/a/270820/145249

@quellenform No, that is simple. I mean spawning them at the beginning and then moving them along.

@DuarteFarrajotaRamos How am I supposed to add clarity when I don't know what it is that people might not understand? If somebody had a specific request for more details, I would be happy to clarify it. Who does it help to just close the question? Do you realize that people go to this forum because they need help?

Hi @Lynx095, simply mentioning "system of points moving along curves" doesn't provide enough context for the community to offer meaningful assistance. It would be really helpful if you could share additional details or screenshots to clarify what you're referring to. Like screenshot of what is happening versus what you are expecting for example. Once you provide more information, we can get the conversation reopened. And as Duarte has mentioned don't make understanding your question rely on downloading a file.

@HarryMcKenzie I chose to share my file instead of a screenshot because the problem I have is in the movement. A good result and a bad result would look identical on a still image.

Your file was initially inaccessible, we encourage using blend-exchange.com instead. Other than that, the problem with sharing a file is that someone unwilling or unable to download cannot understand your question.  Same for some on mobile or unable to open your file. When it is eventually removed, your question becomes incomprehensible for future visitors.
For motion demonstrations share GIFs See https://blender.meta.stackexchange.com/questions/2449

(Using Blender 4.2.1)

Approach based on the Factor

Dark blue nodes: One point every frame is added to the Geometry recycled by the Simulation zone. Two attributes are attached to this point. fac is its normalized curvilinear abscissa along a Spline ; it is initialized at 0.
spline is the index of the Spline this point will travel ; it is drawn randomly.
Dark pink nodes: From its fac and spline attributes, the Position of a point is computed using a Sample Curve node, then it is updated using a Set Position node.
Dark green nodes: The fac abscissa is incremented and stored.
Dark red nodes: Points reaching the end of their spline, i.e. those whose fac abscissa is higher than 1, are deleted.
Resources:
(Blender 4.2.1+)

Approach based on the Length

Using Length instead of Factor to sample the curve requires to base the deletion selection mask on the Spline Length node.
Resources:
(Blender 4.2.1+)

Thank you, it works really well, except for the next step of the project I need it to be based on curve length, not factor. I've already changed it to use length instead but now the nodes that delete the points which reach the end are not working properly. Specifically I have a problem finding the proper length per curve to use for the compare node.

Side note: beware that the length of the curve (a collection of splines) and the length of each spline are not the same property.

solved it, thanks.


text:
BGE Problem with Automated Door (Can't Pass Through)
I've created an automated garage door that opens when a Near sensor is triggered by a vehicle that comes close to it. The door is composed of panels (meshes) parented to a chain of bones that slide them up and down. All of this works fine, but when I drive the vehicle up to the door and it opens, the vehicle can't pass through the opening.
Here's my blend file. You'll have to drive the vehicle to the garage door on the building to see what I'm talking about. If you can tell me what the problem is and how I might fix it, I would really appreciate it!
http://www.pasteall.org/blend/42002

The physics mesh for an object is created at game start, and is not updated based on animations. For some reason armatures, even if they move the whole object, don't seem to update the physics mesh
In this case, it would be easiest to make the elements of the door non-collision, and animate a separate object (eg a cube) that slides up and down to let the player in - without an armature.

Another thing that the BGE can't do. Great.

It is a question of efficiency. The BGE can refresh the physics shape (you do that with a Python calls). But this will eat a lot of processing time.

source: Stack Exchange

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

sort: votes


text:
python socket:send and receive multi objects data
i working on a multi player game project its strategy so i need to sending data for more that one object in the same time i created a client and server and that's worked for one object in the server and one object in the client but after i added the second object to the server i get a proplem not error just 3d objects position proplem and the controller for server objects get swapped for example the server have two objects that's i can get access to control it ["Cube"] and ["Server"] and the server have only one object that's called ["Client"] the proplem is when i run server then i controll my objects the engine swaping the objects in the client screen for example whe i click up arrow to move the ["Server"] object to up the ["Cube"] object who moves in the Client screen and when i click w key to move ["Cube"] object to up the ["Server"] object who moves in the client screen
that's my client code the ["client"] object are connected to it in the game engine
#------------Setup--------------#
from pickle import dumps, loads
from mathutils import Vector
from GameLogic import *
import GameLogic as GameLogic
import bge
from socket import *
import socket
import pickle

cont = GameLogic.getCurrentController()
owner = cont.owner
#obj = cont.owner

if not owner['OneTime']:
  ServerIP = GameLogic.IP
  Serverport = 2052
  Clientname = ''
  ClientPort = 2053
  GameLogic.sClient = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)

  GameLogic.sClient.bind((Clientname,ClientPort))
  GameLogic.host = (ServerIP,Serverport)
  GameLogic.sClient.setblocking(0)
  owner['OneTime'] = 1

PosYou = list(owner.worldPosition)

scene = getCurrentScene()
Cube = scene.objects["Cube"]
Server = scene.objects["Server"]

PosServer = [0,0,0]
PosCube = [0,0,0]
#------------RECEIVE/SEND--------------#

Data = pickle.dumps((PosYou))

GameLogic.sClient.sendto(Data,GameLogic.host)

try:
    #thefucking proplem
    Data, SRIP = GameLogic.sClient.recvfrom(1024)

    UPData = pickle.loads(Data)
    PosServer = [UPData[0],UPData[1],UPData[2]]
    Server.worldPosition = PosServer
    Data2, SRIP2 = GameLogic.sClient.recvfrom(1024)
    UPData2 = pickle.loads(Data2)

    PosCube = [UPData2[0],UPData2[1],UPData2[2]]
    Cube.worldPosition = PosCube

except OSError:
    pass
#---------------THE-END----------------#

that's my server code the ["Server"] object are connected to it in the game engine
#------------Setup--------------#
from GameLogic import *
import GameLogic as GameLogic
import bge
from socket import *
import socket
import pickle

from pickle import *
cont = GameLogic.getCurrentController()
owner = cont.owner
#obj = cont.owner

if not owner['OneTime']:
  Host = "localhost"
  ServerPort = 2052
  GameLogic.sServer = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
  GameLogic.sServer.bind((Host,ServerPort))
  GameLogic.sServer.setblocking(0)
  owner['OneTime'] = True

PosYou = list(owner.worldPosition)

scene = getCurrentScene()
Client = scene.objects["Client"]
Cube = scene.objects["Cube"]
PosClient = [0,0,0]
PosCube = [0,0,0]
#------------RECEIVE/SEND--------------#

try:
    Data, CLIP = GameLogic.sServer.recvfrom(1024)
    UPData = pickle.loads(Data)
    PosClient = [UPData[0],UPData[1],UPData[2]]
    Client.worldPosition = PosClient
    Data = pickle.dumps((PosYou))
    GameLogic.sServer.sendto(Data,CLIP)

except OSError:
    pass
#---------------THE-END----------------#

the second object code the ["Cube"] object and that's connected two the object in the game engine and i get this error when i run it

File "secondob.py", line 18, in AttributeError: 'module' object has no attribute 'sServer'

#------------Setup--------------#
from GameLogic import *
import GameLogic as GameLogic
import bge
from socket import *
import socket
import pickle

from pickle import *
cont2 = GameLogic.getCurrentController()
owner2 = cont2.owner
#obj = cont.owner

GameLogic.sServer.setblocking(0)
PosYou2 = list(owner2.worldPosition)

scene = getCurrentScene()
Client = scene.objects["Client"]
PosClient2 = [0,0,0]
#------------RECEIVE/SEND--------------#

try:

    Data2, CLIP2 = GameLogic.sServer.recvfrom(1024)

    UPData2 = pickle.loads(Data2)
    PosClient2 = [UPData2[0],UPData2[1],UPData2[2]]

    Client.worldPosition = PosClient2
    Data2 = pickle.dumps((PosYou2))
    GameLogic.sServer.sendto(Data2,CLIP2)
except OSError:
    pass
#---------------THE-END----------------#

Welcome to Blender SE! Don't forget to take the tour, so that you can avoid some of the simple mistakes ;-)

Please edit your question. Right now, there's no punctuation which makes it VERY difficult to read. If you make your question hard to read, it won't get read and it won't get answered. Help us help you!

Lastly, this question is NOT off topic (I think), but it is pretty advanced. While the Blender community here is pretty helpful, we generally don't get into advanced scripting like this. Don't delete the question! We'll certainly do our best! But it might be wise to also post this question over at StackOverflow and see if they can help, too.

The problem is global definitions in the beginning of the script. Move cont and owner definitions inside a function and you the function every time to get the reference or pass the reference around in functions. But you can't define them globally outside a function, otherwise 2 objects using the same script share the reference. Monster has written a good guide on this on blenderartists that should be a good read.

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


text:
Game properties break when pre-positioning pieces
I have a game with a 3D board and game pieces. I have the board divided into tiles. When a player clicks on a piece and then a tile, the piece moves there. Right now, it's under construction, so the early primative pieces are floating around in space. All attempts to position the pieces in a starting set up, (this includes positioning by hand, and using the shift-s 'snap to'their  feature,) result in the tiles and pieces losing properties. I cannot select a piece, nor can I select a tile. The rotation of the board still works though.
If it helps to visualize, I made a shot video of my progress for my friends: https://www.youtube.com/watch?v=hwFA1MlgZGY

You have accidentally hit this button:

Which has disabled the manipulator. Not sure if that is the problem you are describing? Note that even with it disabled you can use the shortcut keys 'G' 'R' 'S' for grab, rotate and scale.
I have never heard of moving a piece removing it's game properties though.

That wasn't it. I was using View Persp/Ortho because you can see more of the board.


text:
Geometry Nodes - Connect Points by index
to simplify, I have a set of points laid out like this and I want to be able to connect them with a line or a curve based on a certain index offset, for example: connecting index i with index i+1 only if i is an odd number: so 1 would connect with 2, 3 with 4, 5 with 6 and 7 with 0. (but NOT 2 with 3 for example)
here's what I would like to achieve:

This looks extremely simple but i've been stuck on it for a few days, I can't seem to wrap my head around it, the indices keep changing especially when I instance the lines and realize them: the i and i+1 attributes that I captured before change when the lines are added, so the results become unpredictable.
any help will be much much appreciated.
Update: the workaround I'm using meanwhile is I add a circle with as many points as there are in the input geometry, and I set poistion of the circle's points to match the input points. then I delete the edges with an odd number. this indeed creates the lines between the points but it's not ideal, as I'm planning to add parameters to the lines between the points. so a solution that involves instancing mesh lines or curve lines would be perfect.

Here is a geometry nodes setup that creates edges between every other vertex:

If you want to support both an odd and even amount of vertices this version ignores the last uneven vertex:

Wow, thank you ! I had just realized I could do it with a mesh circle and I read your answer, great timing hahah, is it possible to do it by instancing a line or a curve tho ?? that would be ideal for me, if not, then is there a way to take those edges and convert them to a curve or make them bend inward or outward ??
Thank you so much for your answer.

You can use the Mesh to Curve node to convert the edges to curves and then modify them like you would any other curve.

you're right, I did that and it worked, but I went with subdivide mesh instead and it's giving me more control, thanks again :)

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


text:
How I can create fire particles
How I can create fire particles like this site in blender?
There is a tutorial or an example of this effect ?

Hello and welcome. While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues.

Particle systems are a thing, and emission shaders are a thing. The trick I think will be getting the particles to move about in an erratic fashion, though a turbulence field just might do it. After that, I think lighting just needs to move about and change intensity on a noise function.

Maybe create 2 particle systems, one for the slow ash pieces and one for the fast spark particles. Here is a simple example for the setup (https://i.sstatic.net/CuaBm.jpg) and related question of how to give particles a rotation around their own axis (https://blender.stackexchange.com/q/265806/107598).

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


text:
Unreasonable shine on metallic material with shade smooth
I'm making a cartoony wrench for a video game and I'm getting this strange shine on one part of it because of the combination of metallic material and shade smooth. Auto smooth is on and at 35% and changing that value causes other problems. I tried applying a different material to the affected parts but I couldn't find any values of metallicness or material value that seemed to fix it. I'm guessing that something about the sharp angles is causing this So I tried making them less steep but it didn't seem to help. Is there a fix that doesn't involve changing any of the values I've mentioned?
This is what the wrench looks like at my desired material values and circled is the unwanted shine that looks unrealistic imo.

This is what the wrench looks like in Unity. As you can see the problem persists and I don't plan on adjusting models in Unity though if there is a fix from there I'm open to it.

This is the mesh in edit mode.

This is with Split normals.

Aaaaaand wireframe display.

Show us the normals by turning on the normal overlay (edit mode -> Overlays -> Normals -> Display Split Normals -> Increase Size if necessary).

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

To be honest the question seems a bit pointless, since shading in Blender probably has little to do with shading in whatever game engine you are going to use so solving this in Blender will not necessarily solve the real issues. "Unreasonable" is also not a very certain term. Visually, the geometry itself does not look very reasonable since wrenches usually do not have very sharp edges. Something like this looks more usual visually.

The topology of your model will be central to the way normals are interpolated across and between faces.. so, at least, please switch on wire-frame display, to show us that.

I updated the post with all of the information asked for, let me know if any of it helps and thank you for the help so far!

@GordonBrinkmann custom vertex normals (including auto smooth) actually are often exported, and editing them is a common technique in game modeling.

@gandalf3 That's why I prepared an answer to look out for some things. The split normals in the screenshot seem like there's more going wrong then just faces that are not flat. Problem for me here is, I use Blender and I'm here to help with Blender. I don't use game engines so I'm not familiar with what exactly is exported, I only read here and there that many things are not supported between softwares.

@Sticklad The best help would be if you uploaded the file like moonboots asked for.

@GordonBrinkmann I just uploaded it. I tried everything in the responses and nothing seemed to work except moving the vertices on the top so that they are more aligned, and changing the auto smooth but I mentioned that changes other parts of the wrench and moving the vertex makes the wrench have too sharp of a curve so if possible I would like to fix it with a method that doesn't cause that.

Now that I have downloaded your file I see that we have here one of the most common issues: the scale on your object is not applied. Not applying the scale is the cause for many issues, for example when you try to bevel or inset something - but even problems with smooth shading which I didn't about earlier.
I did not see it in the first screenshot because I paid more attention to the images showing the object in Edit Mode, which does not show the scale. Take a look at the difference before and after applying the scale:

Your object without applied scale. X and Y are not 1, especially Y is quite low.

In Object Mode press Ctrl+A > Apply > Scale so that each axis is now 1, and the shading looks much better.

All in all your object has some non-planar faces which can always cause issues with the shading, so this might not be perfect but applying the scale is one of the most important things if you want to make sure tools and shading behave like expected. By the way, the scale on your mouth is not applied either but I don't know if this is intentional to create mouth movements.

I just recently learned about applying the scale to my objects but I didn't know it could have a practical use like this I thought it was just to make things more uniform. Interestingly I found another solution just now by adding 2 extra sets of vertices along the sharp inner edges of the wrench (think where the object it grips goes). I was planning on making it more curved to see if that fixed things but your solution is much cleaner! Thank you so much for all of your help!

You have definitely some duplicate geometry there. It is hard to tell for all split normals where they belong to because they are so long and overlapping everywhere, but usually each vertex should show two split normals on each corner. But as you can see, some them show three normals or one normal is pointing in the wrong direction regarding the position of the vertex (actually both are pointing in the wrong direction, like all which are labeled "3"):

What I would suggest to do first is making sure that there is no duplicate geometry. To do this, select all vertices in Edit Mode with A, then merge them with M > Merge > By Distance.
And while everything is selected, make sure you don't have any custom split normals data on the mesh because they can mess up the shading as well. To do that go into the Object Data Properties and look under Geometry Data. If there is a button Clear Custom Split Normals Data, click it. If the button says Add Custom Split Normals Data everything is fine and you don't have to click it.

This is likely because the side of the wrench is not perfectly flat. I attempted to reproduce the artifact from your screenshot by moving the selected vertex here slightly:

And you can sort of see how the tweaked vertex's normal is unsplit and at a funny angle compared to the normals of the tip vertex on the opposite side, which is split into two normals at 90 degrees. It's a little hard to see in your screenshot, but I think I can see the some vertex normal lines at similarly funny angles there too. Here's a side view of my version which shows the difference more clearly:

If this is indeed the same artifact as your model, you have a number of ways to fix it:

Just move the vertex back in line. One way to do this:

Enable vertex snapping

Select the unaligned vertices and scale them to 0 along the appropriate axis (for my model, the Y axis) (I only had to move one vertex so I skipped this step in the gif)

Move the vertices along the Y axis and use snapping to align it with the rest:

If you don't want to change the geometry at all, then perhaps the second easiest way is to adjust the auto smooth angle to be a little lower than the angle between adjacent faces where the artifact is:

However finding a value which works will depend on your models geometry and you may have to tweak a few vertices.

Other more advanced options involving normal editing:

Mark the edges around the border as sharp Edge > Mark Sharp (or Ctrl E > Mark Sharp)
Split those verticies' normals manually Mesh > Normals > Split (or AltN > Split)

To make sure you normal edits are preserved when you export to unity, make sure you're using a format which stores vertex normals, such as gltf. If you are using gltf, also make sure vertex normal export is enabled.

I briefly skimmed your answer and will look more into it when I get back to working on it but thank you so much for such detailed help!!!


text:
can't undertand what is wrong weight paint fingers

hi, please someone can say me what's wrong? it's a file that i didn't open for two weeks, it worked well last time but now i have a problem with fingers. i added bones last time and i checked all the bones but no one except the right bones influence the fingers. why they deformate? how can i fast understand where is the problem?
EDIT: post another image, the right arm it's ok, the problem is the left. i can't understand.
i did a simple armature, then i worked with shape keys for face animations or biceps, i deleted them in the right way but have this. now i controll if i have older file of this

i solved reworking on the topology of the fingers, I didn't understand what happened but ok


text:
Blender 2.76b - Slow performance on Viewport Shading Material

I'm running Blender on Ubuntu 18.04 LTS; I use Blender 2.76b. My problem is when I turn the Viewport Shading to Material Mode, it is very very slow. It is even much slower (much!) than the Rendered Mode. Literally, I can't even move the view naturally.
The official site of Blender says that the version 2.76 is the last compatible with OpenGL 1.4 (That is the version that I have), therefore, should not present me any problem.
I do not have a dedicated graphics card, but the integrated Intel chip. This, for its time, should not present problems of incompatibility due to Driver issues.

[UPDATE]
The problem persists in versions 2.75a, 2.76, 2.76a and 2.76b, I have not tried other older versions. There is an irrelevant performance improvement between version 2.75a and 2.76b.
Thanks, first of all.


text:
Looking for help with my Ngons
So in my attached .blend file, (I have also attached .jpgs of my original design for you to see what I'm trying to model) you can see that I have two separate meshes. I can bevel the bottom one properly, but the top mesh cannot be beveled; this is most likely due to bad geometry on my part from creating too many of the top faces and crevices with curves (please note that no booleans were done on this model). I've already done a quick and dirty way of making all the faces into tris and quads with a few clicks from a youtube video tutorial. But of course that didn't solve the problem either; it still didn't bevel (likely due to the tris).
Should I just go in and manually change all the ngon faces to quads? And even then, would that truly make it possible to bevel, or would I just be wasting time? Is there a faster way that I just don't know about, or is this unsalvageable? It's the only option I can think of at the moment besides relying on the Bevel Node, which I'd rather not as I want to solve the root of the problem and not just hide it with a node.
Blender file: https://drive.google.com/open?id=1kKDFScmYSetTtOO8_wSyaIiJJBMm27r6

what part would you like to bevel and can't? perhaps give an example

@moonboots I would like to bevel the entire top mesh as I've beveled the entire bottom mesh with the bevel modifier, as I would like to remove all the harsh edges it contains to add a bit more realism.

May be the possible solutions :

Best option : Manually edit and make it quads.
Option 2 : convert to
triangles-> decimate modifier(try planner)-> convert to tris->convert
to quads-> remove doubles  ( try adding bevel modifier)
option 3 :
remove doubles if any -> add a bevel modifier
option 4 : subdivide
too much-> export to zbrush and use decimation process


text:
Where to apply seams when unwrapping a head?
Just wondered if there's a 'benchmark / gold standard' for where to apply seams when unwrapping a head, i.e; include ears in the main island or exclude them, - where to roughly start and stop the center-seam etc etc.
If there's a good tutorial that you've seen, or you've already got great methodology published on the web somewhere, I'd love to see it... I just can't seem to find a set of joins that I'm totally happy with.
Thanks in advance

it depends on how you plan to texture your head, if you plan to paint on it you can simply unwrap with the Smart UV Project, it doesn't need any seam

Hi Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the [edit] link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?""

One technique is to unwrap the face vertically and symmetrically so you can easily edit the image texture in an image editor. If you want to have the scalp, ears on separate UV islands depends on how much texture space and details you want to give them. To use the space effectively you can unwrap the face with closed eyes and mouth. Game modes are often unwrapped like this: https://blender.stackexchange.com/q/221373/107598 - Here is a live stream from Blender Studio: https://youtu.be/_LI28r-Nk5g and here a tutorial: https://youtu.be/ZyRtd8iYBOg


text:
Grooming a cowlick
Using hair geometry nodes, I'm having a problem grooming a cowlick like the ones on horses. When I tried to groom four guide curves in different directions, the interpolated hairs don't follow them at all. What do I do?

Can you provide the blend file? Coz I had no issues

@Akshay2005 I don't know how to do that.

Either use https://blend-exchange.com/ or if larger than 30MB just upload it to your drive and share the link.

I could not really understand the reason completely and so I won't be able to give you an answer. But if you just want to fix this, then for now just change the interpolation guides amount to 3 instead of the current 4.

Even with three interpolation guides, the interpolated hairs are still off.

Uh, I mean the amount in the modifier not the guides that you created.


text:
How do I animate a character without creating 100's of keyframes?
I have a basic rig with a character.  The only things that are moving are the torso, arms, and the knees.
For my beginning pose, I insert every available keyframe as the base pose.  On phase 2, I update the torso, arms, knees, etc.  Then I copy all the keyframes from pose 1, to set it back to normal.
Do you see the issue here? In pose 1 and pose 3, there are 100's of keyframes that need to be cleaned up because they're not being updated?  The only way I can think of cleaning these up is the go into the Action Editor and deselect all the bones I'm not updating and delete the rest.

I'd suggest you watch a simple animation tutorial! In Pose mode, at frame 1 select the whole armature with 'A' and hit 'I' > Location, Rotation and Scale. Move the Timeline marker to your 'phase 2' frame, pose your model, then hit 'I' > Loc, Rot & Scale again. (You only need to do this with the bones you've moved but selecting All and insert them all again is probably easier in your case.) Then you can go back to frame 1, box-select your keyframes, hit Shift-D to Duplicate then drag them to your final frame. There's no need to use the action editor at all.

Wouldn't this have keyframes for every bone in all 3 phases?  You're duping everything.  The way I had it before, at least phase 2 only had the bones I wanted to move.

Yes it would, but that's the easiest way in your case and doesn't really matter. You could also set keyframes for everything on the first frame. Turn on Auto Keying (Top of the Timeline to the left of the movement icons), pose your model, then move on one frame. Then do the duplication as before. Don't forget to turn off Auto Keying though as any movement will be recorded which might not be what you want and is why I rarely use it.

Actually you only need to use Location and Rotation unless you intend to scale any bones, and if you think about it moving the torso will also move all the bones above it in the model at the same time, so keyframing the whole model is necessary or it will try to pull itself apart!

No offense, but that is the way I was trying to avoid because of all the keyframes I don't need.  I guess there's no short way to do it without deleting them manually on the frame.

You may not think you need the keyframes, but the armature certainly will!


text:
Material preview doesn't work
When I add an image texture to my object, I can't see it when I press material preview. The image I'm trying to use to colour it is very bright and colourful, but it just looks black.

I've added a video recording so you can see all my steps and tell me if I'm doing anything wrong.
https://drive.google.com/file/d/1y6ggs8o_Q4pZsTZLtvdPAiBaqnkGVBZ-/view?usp=sharing
https://drive.google.com/file/d/1g7myoPiNIv1g0aqXMH6-J-4FLgIzaMXV/view?usp=sharing

could you please pack your image (File > External Data > Pack Resources) and share your file? https://blend-exchange.com/

Hello, just added it now. Thanks for your reply

As Yousuf Chaudhry says it's a problem of unwrap, but your mesh is high-poly, do you really need a high-poly mesh? Also, the way you'll unwrap will determine how the image will be projected on the object, a Smart UV Project unwrap will give unexpected result, unwrapping with seam will give you more control but as I said your mesh is high-poly so it seems complicated... But you have other ways like Project from View etc

@moonboots isn't the mesh low-poly?

@Yousuf Chaudhry no, it's 55,000 faces, plus it's triangulated, so it will be hard to seam  ;)

@moonboots You're right, but I though 10 million-plus faces were high-poly (1 million's my minimum base for every project, on average every project of mine, even if very small, is 10 million faces) ^_^

Sure, it all depends on the purpose actually, for 3D print it may be necessary, but for an animated character I don't think it's a good mesh  ;)

You haven't shared your file, so it is impossible to know the exact problem.
However, the closest possible to an answer is that the UVs are not unwrapped, so all you can see is a black preview.
To unwrap it, select your model, go to Edit Mode, and select all by pressing A. Then press U > Smart UV Project if you want to do it automatically without adding seams.
If that doesn't work, you can select an Edge Loop by pressing Alt + LMB and press U > Mark Seam. Then, after adding the seams to the appropriate places, select all and press U > Unwrap.
If you don't know UV Unwrapping, I recommend you search up some of the thousands of tutorials on them on YouTube.

Thank you, that first step worked

@beatrixhaxby If the answer solved your problem, kindly consider accepting it by pressing the checkbox on the top-left.


text:
Dark glass with weird imperfections
I am following Blender Guru's donut & teacup tutorial and have gotten up to part 3 level 3 where I am starting to make my teacup transparent. After following all the steps in the video I am left with a glass material different from his. It is darker in some spots and has weird squiggly lines. Here are the render, material settings, and light path settings respectively.
Could somebody please help me fix this?

Above in the render, the dark parts I'm talking about are where it suddenly goes from pink to very dark pink. This is also where you can find the weird squiggly imperfections.
Thanks.

hello, maybe it has to do with your topology?

could you please highlight the parts you're talking about? the handle has edge creases, to remove them, select all and Ctrl E > Edge Crease and in the Operator box, lower it down to 0

Yeah ok I'll edit the post including a photo that shows where I'm talking about

the squigglies are denoiser artifacts

Ok thanks, do you have any idea what could be causing the darkness?

Try an HDRI for the lighting. You will get nice reflections and it brightens the darkness: https://i.sstatic.net/491mt.jpg

Edge Crease makes the edges sharp when used with Subdivision Surface.
What I did was select a few edge loops in different places and X -> Dissolve Edges.  On most of the remaining geometry I removed the creases.
With the reduced geometry it's easier to place and rotate a few control loops and let Subdivision Surface fill in everything between.

If you turn Clamping -> Indirect Light and Caustics -> Filter Glossy to 0 it'll stop the glass from darkening your scene so much, but the scene will take some time to clean up the noise.  With the viewport denoiser on it looks like this at 128 samples.

Thank you, you're an absolute legend. Now that I have fixed it could you please briefly explain what changing these lighting settings did, I'm a newbie to Blender and I want to fully understand every step I take. Thanks again.

I have an answer with some comparisons, but basically it's clamping the light being added to the scene when the ray passes through something. https://blender.stackexchange.com/questions/219303/glass-casting-shadows-and-not-looking-real/219957#219957

@Matthew If this answer was helpful, be sure to upvote, and if it solved your problem to accept as well :)


text:
How can I add motion to a rigid body?
I'm trying to create a bowling animation and I want the ball to hit the pins.
I already added the Rigid Body physics to the objects but can't get the ball to move.
Obviously I could just add keyframes but

that seems to interfere with the Rigid Body physics
it doesn't look too realistic.

Is there a way to add some kind of motion to the ball?

Using keyframes is the only way I know of to do this currently, but you should be able to get good results by allowing the rigidbody object to be controlled by the animating system, then switching control back to the physics system while maintaining momentum gained from the keyframe animation.
This can be done by animating the Animated option in Physics > Rigid Body.
See the wiki:

The most common trick is to keyframe animate the location or rotation of an Active physics object as well as the Animated checkbox. When the curve on the Animated property switches to disabled, the physics engine takes over using the object's last known location, rotation and velocities.

Also see this post
For example:

Enable Animated on your rigidbody object and insert a keyframe by right clicking on the check box and selecting Insert Keyframe:

On the same frame, add a location keyframe (or rotation if you want some angular momentum) to the rigid body object

Go to a later frame and insert another location keyframe

On the same frame, disable Animated and insert a keyframe by right clicking on the Animated checkbox and selecting Insert Keyframe again.

The motion from the keyframed animation will be carried over to the motion of the object as it is controlled by the physics system.
Result:

Note that while Animated is enabled the object will still interact with other rigid bodies, however its motion will be controlled by the animation system.

Is there any way to simply set the object's velocity at the first frame?

@snapfractalpop Not currently.

Ok. I just tried your method, and I found that I needed to have at least two frames with "animated" checked. I guess that is needed to calculate momentum.

@snapfractalpop Yes, exactly. The object needs to be moving when the rigid body simulator takes over.

It doesn't appear to be working. Can you give a .blend download so I can analyze what you did for that bowling ball example.

@TheMinecrafterandBlendmist I've added a link to the answer

I can't find the "Animated" checkbox. What am I missing?

@AlexanderPruss It's in the physics tab (bouncy-ball icon) of the properties area (usually on the right), under the Rigid Body heading when Rigid Body > Type is set to Active.

@gandalf3: Under "Physics", I have "Physics Type: Rigid Body [dropdown]". Then I have checkboxes "Actor", "Ghost", "Use Material Force", "Rotate from Normal" and "No Sleeping". I don't see "Active" anywhere.

@AlexanderPruss Ah, it seems you are using the BGE (blender game engine). This answer is for using rigid body physics in the 3D view, outside the BGE. If the BGE is what you want, have a look at GameObject.setLinearVelocity()

I have created an addon to make this process described by gandalf3 easier. It's called Projectile. Download it from GitHub. The download is for 2.8x, for a 2.7x version see this branch
To use it

Select an object
In the sidebar (N panel) there is a panel called Projectile. In the panel is a button titled "Add Object." Click to initialize velocity.
In the Velocity Settings subpanel, set the velocity. By default, the operator will run each time a setting is changed.
Then play the animation! You will see the object start with an initial velocity.
There are many other settings like initial location and rotation, start frame, angular velocity, physics solver quality, auto updating, auto play, trajectory drawing. Experiment with the settings to get a good result.

For more detailed instructions see the readme on GitHub.

This is fantastic! Works as advertised.

I wondered a similar thing (Using "Rigid Body" for rolling ball. Flat surface. How to push the ball to roll?) and someone in the comment mentioned this question. The top answer worked, but only when I had sufficient length of moving animation right before the physics (moving between frame 1 and 2 did not work, I had to make it between frame 1 and 20). But that defeats the purpose of this physics movement. I was thinking about adding this physics movement because I wanted to avoid the unrealistic sliding animation, and now I have to add it to make the physics work.
So, I modified the top answer slightly. Instead of animating the ball itself, I added an invisible cube and animated that cube. Basically the cube hits the ball, and the ball starts to rolling. I extrude the top part of the cube a little bit so it would hit the top part of the ball. I am not sure if it affects the animation or not.

You don't need to add any special keyframes to the ball itself. Do

Add a cube to some tens of frames before, set keyframes on its location.
Make the cube a "Rigid Body"
At the frame you want the ball to start rolling, move the cube to a location where it slightly touches the ball and set keyframes on the cube's location.
Make the cube invisible in the render result (Outliner -> filter -> camera icon -> uncheck for the cube)

I would like to post a python script implementation of @gandalf3's idea.
I am new to blender, I have read What is the correct python code for pressing "I" and selecting LocRotScale? and How to use Keyframes and the Python API programmatically?. Referring to how to find the data_path for scripted keyframes, I finally get the following:
bpy.context.scene.frame_set(5)
cube.rigid_body.kinematic = True
cube.keyframe_insert(data_path="rigid_body.kinematic")
cube.keyframe_insert(data_path="location")
cube.keyframe_insert(data_path="rotation_euler")
bpy.context.scene.frame_set(10)
cube.keyframe_insert(data_path="location")
cube.keyframe_insert(data_path="rotation_euler")
cube.rigid_body.kinematic = False
cube.keyframe_insert(data_path="rigid_body.kinematic")

In this way, one can first control the rigid body motion manually, and then transfer the control to the physics system.
I also find the following links may be useful：
Simulations Rigid Bodies and The manual.

hellohawaii, your answer looks promising. Would you please post the entire script and give a complete but simple example of how to successfully use it? Even after adding "import bpy" at the top of script, I get "name 'cube' is not defined".


text:
Blender not exporting Ambient Coefficient in .MTL?
Here are my settings:

Export settings:

In '.mtl'
newmtl c0
Ns 19.607843
Ka 0.000000 0.000000 0.000000
Kd 0.000000 0.077046 0.638270
Ks 0.882353 0.882353 0.882353
Ni 1.000000
d 1.000000
illum 2

I don't think that Ambient Cooefficient is supported by .mtl. There's more info on .mtl files here: http://web.archive.org/web/20080813073052/http://local.wasp.uwa.edu.au/~pbourke/dataformats/mtl/

It would help if we knew what you were trying to do and what you expect the Ambient value to be. This Ambient value is related to the render engine and doesn't really have anything to do with the material as it could be used outside Blender.

Related, Export Wavefront .mtl file — Where is the reflectance coefficient?.

Basically you can see Specular which is 'white' is the value 'Ks', Diffuse is 'Kd', but Ambient which is 1.0 is just 0.0 in 'Ka'. How do I change the value of 'Ka' when my materials are exported?

@CharlesL: from the link you provided: "To specify the ambient reflectivity of the current material, you can use the "Ka" statement (...)"

@SyntheCypher, you should elaborate your question, specifying that "Ka" parameter correspond to Ambient reflectivity.


text:
Get name of bgl_RenderedTexture in Python
I want to let the GPU create a mipmap for the framebuffer texture that's available as bgl_RenderedTexture in the custom filters.
It shouldn't be difficult. I just put some code into the post_draw list:
glBindTexture(GL_TEXTURE_2D, bgl_RenderedTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glGenerateMipmap(GL_TEXTURE_2D);

But there's no variable bgl_RenderedTexture. Is there a way to get the texture name for the framebuffer?


text:
How to change the default value of Image compression?
Hello I found a little problem right now I'm working in a project using blender I bake a lot of textures but since this bakings are a lot of test I want compress at 100% why because I use a Git repository and that increases the repository size.(Of course I try to avoid binary files)
So after explain what I'm doing I'm tired of change the value every time that I open Blender.Compression value is 15% I want to change that default when I start blender

I already tried to use Ctrl+Alt+U. System Tab->save users settings that is OK with the plugins but I always have to change Compression value 15% When I open a new blender file.

Possible duplicate of How to change Blender's default startup settings?

So the compression value is not part of the User Settings is actually a value of the blend file.

Correct. The User Preferences doesn't really control default values for values visible in the UI (there would be too many to list in the preferences), that's the job of the startup file.

Set the compression level to 100%, then press ⎈ CtrlU> Save startup file.
Note that this will save everything, including view position, objects, etc. as default.


text:
Reset origin of objects after file import (from Cinema 4D)
After import of a house model into Blender, all objects have a reference I don't know how to handle. I setup all to Meters and yes, I can scale it down and move manually and find a camera which works. But all models has values like -13000 but only as origin as it looks like. Every movement and rotation becomes horrible. How to fix the origin issue in Blender for file import??
It occurs on obj, dae, 3ds files and others.
Download project

Can you edit your question and upload a .blend?

how to upload to giantcow?

Thanks. I did not know that it comes from single person. Anyway I uploaded the file. Is it possible that it an be the "parenting" or "transition" instead of origin?

I found I had the same problem when importing obj's exported from sketchup.
In order to fix it.
Select all the objects in object mode by pressing a.
Press (shift + ctrl + alt + c) or press space and type "set origin"
Chose either "origin to geometry" or "origin to centre of mass"

After you bring any object into a new file, whether by appending from another blender file, or by importing a file from another format, the first actions you should take are to apply rotation, scale, and location. If the object's origin point is not where you want it, you can set the 3D cursor where you want the origin, and use CTRLSHFTALTC to move the object origin to the 3D cursor.

sorry, does not work. I have uploaded the file.


text:
Fblah's tools in Blender 2.92
I've successfully downloaded and installed the Shape Key Tools by Ajit Christopher D'Monte into Blender 2.92. The tools menu shows up in the right margin as it should.
There should however also be a menu called Fblah's tools that I cannot locate. In some cases addons put their tools in different places such as Add menu but I can't even find a reference to it there. Does anybody know where to find this menu?
EDIT 1: This is what my tools-menu looks like.

EDIT 2: Still not really there - the "copy inverted bones rotation"-button is missing.

Looks as if it may not have been updated for version 2.9 according to the readme.md doc. It's a third-party addon so best to contact the author.

Ahh. Funny since it seems to be his own creation. I'll pass him a note asking where that menu is. If I get an anser I could post it here for others to know too. Thank you for your quick response John. :)

The addon seems to be broken on the latest version of Blender 2.93. I have been using Blender 2.92 and it works there. I am looking for a solution to the problem. Other addons also seem to have broken with this update. The issue is with the mesh picker and list box, I'm looking through the Blender documentation to update the code but can't find any leads yet for a fix.
You can get 2.92 here: https://download.blender.org/release/Blender2.92/

Please let us know whenever you find a solution so I can download an update of the add-on. :)

It has been updated. Please check and let me know if the issues have been resolved.
https://github.com/fblah/ShapeKeyTransferBlender

Great work. We're still not really there - I can't copy inverted bone rotations since that button is not there. :) Please have a look at the screen dump in my updated question.

The button will be visible once you pick a destination mesh. Here is a tutorial video with example use cases: https://www.youtube.com/watch?v=-zBlaedkkVs

Hey again. I don't know if we are talking about the same thing. The entire fBlah's tools is missing. No buttons related to that tool is even there as you can see in my screenshots. Only the shape key tools are there but no fBlah.

Is it possible for you to join my discord and screenshare the issue? The link is in the github.

I've tried to enter the Discord but I can't sign in. I reach a "Whoops - we can't sign in". Can I email my screenshots?

I just figured out what is wrong here. These are TWO different tools. I thougt it was part of the Shape Key Tools but i's not. It's a stand-alone add-on called Fblah's tools. Here's the Git: https://github.com/fblah/fBlahTools/tree/Blender293. Unfortunately I still can't get the buttons to show even though I've installed this add-on in Blender 2.93. Is this add-on broken?

Yes thats a separate addon and it is upto date. Can you send me an email with the screenshots? Also I don't know how to use blender 2.93 I find the interface a bit confusing so I still use 2.79. In blender 2.79 and 2.8 you have to be in Object Mode to be able to access the tool.

Regardless of being in Object view or not it’s still not showing up. I just sent you an email with a screenshot of my Blender workspace to explain what I’m seeing (or rather what I’m not seeing)

I'm sorry I haven't had the time to update this plugin to version 2.92 yet but I can confirm that the version built for 2.8 works fine on Blender 2.92. The menu will show up under the Tools tab. Press N on the keyboard to show it.

I've updated my question with a screenshot of my tools-menu since what is seen in your screenshot is not what I see in mine. Have I missed a setting?


text:
How to remove unintentional distortion from geometry?
Maybe this question already has an answer, but I'm uncertain of how to ask this question in a good way, so here we go.
My geometry seen below is rendered quite funny with a distortion that seems to be added across the geometry that can't be removed by replacing old vertices with new ones. There are no vertices duplicates in the mesh and I have reset the normals (funny thing the distortion moves around whenever I reset normals).
Is there any way to remove this distortion that I have missed? I am using Blender 2.83.

So, this turned out to be much easier than I anticipated. It is all about flipped normals where some faces have their normal vectors pointing inside the mesh instead of outside. It can be shown in Edit mode (face mode) with face dots and face orientation enabled in the Overlays like this:

It turns out all you need to do is select all the faces on the mesh and recalculate the normals (you want blue facing outward; blue is facing toward you and red is facing away from you). Another way to see the direction of the face normals (instead of turning on Face Orientation) is by showing their vectors:

Big thanks to Chris Kohl (ckhol_art) over at https://blenderartists.org/t/how-to-remove-unintentional-distortion-from-geometry/1241104/3 for providing me with this fantastic answer and explanation.

A much faster way to fix this is, while editing, select all vertices of the problematic object ('select all' / A will often work; in your case you might want to select only the vertices of a single body-panel), then Mesh > Normals > Recalculate Outside (Shift+N).


text:
Blender to Unity 5: Using more than 1 rig with animations
I have a model that is rigged and also a weapon that is rigged. The rig of the weapon is connected to the model's hand so that it moves accordingly (I connected it with CNTRL+P > Set parent to bone). I then made the animations for the model and then the bow and combined them using the NLA editor. The problem is, when I use the .blend file in Unity 5, the weapon doesn't move, only the model. Am I joining the two incorrectly or am I just using the NLA editor wrong? Thanks.
Edit: I don't actually save anything in the NLA editor because I assumed you didn't have to (and I don't see any save button xD). I'm very confused as to how I'm supposed to get whatever I just made in the NLA editor into something I can use in Unity.

I don't think the NLA strips do get exported to unity, only the Actions do get exported (keyframe animations)..

@Jerryno Okay, so then if I want to move both my model and weapon in the same animation I need to combine the rig or something?

Yes that's one way it would work, but then you can't swap weapons - it would be one skinned mesh with one armature. You can export both models separately with own animations and synchronize them in engine.

@Jerryno I see. Well I only need one weapon for this purpose as it's the first time I'm actually making stuff in blender. Thanks, I'll try that out.


text:
How do I create an empty blender file .blend from C?
How do I create an empty ~.blend file using C?
I need to create a blender file directly from my program. Is there a simple example or tutorial for this? Any library?

Do you want to create an empty Blender file, or do you want to create the default startup file?
This link may be of help to you:
http://archive.blender.org/development/architecture/blender-file-format/
Why don't you just open Blender, modify the scene to how you want, and then save that out to a file on disk? That way you could reference the saved file from within your C program, and add to it as you please? Or is there a specific reason why you need to programatically create the file from scratch?

emty file .blend  I need create program to produce blender object and all important setting. I canot run blender.

Why can't you run blender?  And why would writing a custom app that does exactly what blender does, not fall under the same limitations?

A dlaczego nie? Wyobraź sobie, że można zrobić aplikację webową. Możesz np. z jakis danych wygenerować plik blendera. OpenSCAD potrafi generować obiekty do druku 3D. Lepiej zrobić to od razu w Blenderze. Blender jest za wielki na serwer www.

Mając taką możliwość można zrobić interface też do innych języków np. Ruby.

Probably save your own custom empty blender file, package/embed that in your app and copy it as your new blender files.

I don't know why you'd want a completely empty file, but you should be able to create a new .txt, make sure you can view file extensions, rename the .txt to have a .blend extension, voila.

empty file is only begining ;-)

authors: Борис Ермаков


text:
How add primitives or other objects to scene using python
I found many old information. Where is simple example to add all primitives (completly working example with actual blender)
I need put cylinder, and move it into specyfic location, seting scale and assign color and name. Im not using mesh, faces etc, I need only primitives like box or torus....

This site is more for single questions at a time, importing would be a different topic to creating primitives. See if this answer helps with importing.

There are several operators that add primitive objects to a scene, look at the reference for each to see all available options.
An example of adding several objects -
import bpy

for x in range(10):
    bpy.ops.mesh.primitive_cone_add(location=(x,0.0,1.0), radius1=0.5, radius2=0.1)
    bpy.ops.mesh.primitive_cube_add(location=(x,0.0,2.0), radius=0.5)
    bpy.ops.mesh.primitive_ico_sphere_add(location=(x,0.0,3.0), size=0.5)
    bpy.ops.mesh.primitive_monkey_add(location=(x,0.0,4.0), radius=0.5)

You can also find similar operators available when using bmesh, which is a better option when you want to edit mesh objects, or build more complex models.
Note that after you add an object using one of the primitive operators, it becomes the active object, that means you can get the object using bpy.context.active_object and make further adjustments after you have created it.
This answer gives an example of creating multiple materials and assigning them to different faces.

How put color to this primitoves? This is trouble because colors is less than objects. I need 4 colorb but objects have 100. Trouble is how create materials without objects.

I have color in html #hexhexhex or in rgb in integer

@MarkoLustro This answer is an example of creating a BI material. Cycles nodes takes a bit more. Blender takes rgb values as floats, that is 0.0-1.0 matches 0-255 so if you have red as 127 use 127/255 to get the float equivalent. You use int('BB', 16) to turn the hex into an int or together as int('BB',16)/255.

Yes , colors working, thanks. The trouble is how add this color to the scene and save it in 'F' mode (alvays in blender file)

mat.use_fake_user = True - that property is common between all items that support a fake user.


text:
Weird artifacting when baking my normals
So, I'm attempting to bake a high poly onto a retopo version. I am running into issues, however, where the baked normals looks kind of blocky in parts instead of smooth. I'm kind of new to retopology and know parts of my model looks strange on the sides (it's a sweater where most of the material is gonna be covered by a jacket so I didn't bother being perfect in those spots).

the retopo version is a bit messy but shade smooth it try a new bake maybe? If it still doesn't work please share your file: https://pasteall.org/blend/

Oh, so I did the shade smooth at one point and it does look better. But if I want to eventually import this character's clothing into Unreal Engine, will the smooth shading continue to take effect? Also, my file is ~125 mb, so I don't think I can upload it to pasteall. Is there a workaround? I guess I could delete the highpoly mesh from the file but maybe that would delete the purpose of this?

fixed the image attachment issue. sorry about the imgur link!

Thanks for the fix :-) If the file is too big for pasteall.org you could share it by Google drive, dropbox or a file hoster like mega.nz or wetransfer.com

I don't know anything about Unreal, I guess you can shade smooth in Unreal. As Blunder says try another platform.

Thanks moonboots, I hope Unreal has that feature if all else fails haha! Also, here is the google drive link (file is slightly bigger 'cause I needed to pack all the files into it). Also note there is a texture in there that is imported from Substance. It's separate from the baked normals I'm having issues with though. https://drive.google.com/file/d/1X8hGhwD0DTNaZ33CaeTkI6qp0nSIfGpq/view?usp=sharing

So once you shade smooth the bake looks ok. I think you don't have to worry about Unreal as it will keep the Blender shading. You could probably simplify the topology but that's another question...

Hey that's a good enough answer for me! Whatever shortcuts I can take to help with the final product sounds awesome! Thanks a lot!

So once you shade smooth the low-poly, the bake looks ok. I think you don't have to worry about Unreal as it will keep the Blender shading. You could probably simplify the topology but that's another question.


text:
2.8 Sculpting Resolution?
Newbie sculpting question. When using dynotopo, it looks like a resolution of 10 is a low resolution? Am I understanding this correctly? If so, what number would be considered high resolution for final character detail? Cheers!

Which method detail size mode do you ask about, Constant or Relative, or Brush? I don't think there's any certain numbers which can be "ideal for character" or "perfect for organic creature". It all depends on project, artistic needs etc.

Sorry I'm using "subdivide collapse" and "constant detail." Is it more just about watching the Verts, Tris?

Usually sculpting is done without worrying about polygons count as the details are meant to be baked  into normal map to be used withh lowpoly mesh in the end app. Although it is not always the case, sometimes sculpting is done with as much details as possible and as few polygons as reasonable to have. Again, so far this question is too broad. What's the purpose of the mesh created with dyntopo?

The size used by dynamic topology relates to the visible size of the mesh details. You can also think of it as distance between vertices.
So the smaller the size used, the smaller the details, which means more vertices in your mesh that are closer together.
What the size value refers to depends on the detail type selected :-

Relative Detail uses screen pixels
Constant Detail uses blender units
Brush Detail uses the brush size


text:
Drive shape key based on relative camera orientation?
Let's say (for the sake of simplicity) that this cube with two blue sides is my character...

and the shape key in question raises a few vertices on top.

Whenever the camera views either Blue side, I'd like the shape key to activate regardless of world orientation through the use of a driver. The problem is, I have no idea how to get values I need (or which values I need to begin with) in order to automate this.

TL;DR - I'd like the mesh of a character I have to deform when viewed from the side much like what was done in Land of the Lustrous

*Note: While I do have some experience with coding, I've never used python. Layman's terms would be greatly appreciated. Thank you for your time!

UPDATE: In response to @Leander's post
Would it be possible to have this script work with multiple characters on the same camera? Let's say I have character "Cube2" with shape key "Key 2", would simply adding variables like below accomplish this?
import bpy
import mathutils

cam = bpy.context.scene.objects['Camera']
obj = bpy.context.scene.objects['Cube']

# -----------------------------
# Adding Cube2

obj2 = bpy.context.scene.objects['Cube2']

# -----------------------------

def drive_shapekey(scene):
    obj_mat = cam.matrix_world.inverted() * obj.matrix_world

    obj_eul = obj_mat.to_euler('XYZ')
    cam_vec = obj_mat.to_translation().normalized()
    obj_vec = mathutils.Vector((0.0, 1.0, 0.0))
    obj_vec.rotate(obj_eul)
    difference = cam_vec.dot(obj_vec)

    key1 = obj.data.shape_keys.key_blocks["Key 1"]
    key1.value = difference

# -----------------------------
# Adding Cube2 properties and shapekey 2

def drive_shapekey2(scene):
    obj2_mat = cam.matrix_world.inverted() * obj2.matrix_world

    obj2_eul = obj2_mat.to_euler('XYZ')
    cam_vec2 = obj2_mat.to_translation().normalized()
    obj2_vec = mathutils.Vector((0.0, 1.0, 0.0))
    obj2_vec.rotate(obj2_eul)
    difference2 = cam_vec2.dot(obj2_vec)

    key2 = obj2.data.shape_keys.key_blocks["Key 2"]
    key2.value = difference2

# -----------------------------

pre_handlers = bpy.app.handlers.scene_update_pre
[pre_handlers.remove(h) for h in pre_handlers if h.__name__ == "drive_shapekey"]
pre_handlers.append(drive_shapekey)

# -----------------------------
# Not sure if this'll work, but we'll see

[pre_handlers.remove(h) for h in pre_handlers if h.__name__ == "drive_shapekey2"]
pre_handlers.append(drive_shapekey2)

# -----------------------------

Drivers might help achieve this

This answer targets a beginners level and will include lots of lengthy explanations.
I understand that this answer doesn't utilize drivers as requested, but for this example a simple python script is very easy to produce and maintain, which is why I wanted to add this method.
A slight problem is, that a change of position implies a change of viewing angle with perspective cameras. In the next image there is no difference between both objects orientation, but through the camera, the objects appear clearly at an angle.

I would use a script which check's the camera's and object's transformations on each scene update.
Let's start with a condensed example. Create a camera Camera and a mesh Cube. Then add the Basis shapekey and a Key 1 key, very similiar to the setup in the question.
Paste the following python script in the text editor and click the Run Script button. I have made an effort to document it well.
# import the bpy module, with it we can access the data of the blend file
import bpy

# bpy.context.scene stores the active scene.
# The scene stores a collection of objects, from which
# objects can be accessed directly with their name.
# Get the Camera and Cube by their names and store them
# in "cam" and "obj" variables respectively
cam = bpy.context.scene.objects['Camera']
obj = bpy.context.scene.objects['Cube']

# define a method which will get called on every scene_update
def drive_shapekey(scene):
    # store the transformed obj.matrix in the obj_mat variable
    obj_mat = cam.matrix_world.inverted() * obj.matrix_world

    # print it to the blender console for possible inspection
    print(obj_mat)

    # get the location, rotation and scale from the matrix
    obj_loc, obj_rot, obj_sca = obj_mat.decompose()

    # access the shapekey "Key 1", note that there has to be a
    # shapekey with that exact name
    key1 = obj.data.shape_keys.key_blocks["Key 1"]

    # access the "Key 1" shapekey value
    # here, we assign the absolute value of the objects x location
    # transformed by the inverted camera matrix (!)
    key1.value = abs(obj_loc.x)

# We have to store the method in the scene_update_pre collection.
# First, loop through the collection and possibly remove other
# methods, then append our "drive_shapekey" method. This method
# will then get called on each scene_update_pre cycle.
pre_handlers = bpy.app.handlers.scene_update_pre
[pre_handlers.remove(h) for h in pre_handlers]
pre_handlers.append(drive_shapekey)

One of the more complex lines is
obj_mat = cam.matrix_world.inverted() * obj.matrix_world
The matrix_world is the global transformation of an object (global meaning with parenting already applied). If a location Vector would get multiplied by an object's matrix it will appear is if moved as a child of the object. By multiplying the object's matrix with the camera's inverted matrix, we get the object's matrix in camera space. This may be a confusing concept. The following gif demonstrates multiplying a position vector with the camera matrix or the inverted camera matrix.

The result of the above script is an interactive handler, which update the shapekey value, based on the relative position between the object and the camera.

In the next step, we'll chose the value, which we want to influence the shapekey: the difference between camera and object orientation. Once we have the object's matrix in camera space, we can ignore whatever values were on the camera, since they have been transfered to the object. Only change the code of the drive_shapekey method and leave the other lines intact. In this sample, we use the rotation value of the transformed object matrix by compared a vector with its rotated counterpart.
def drive_shapekey(scene):
    obj_mat = cam.matrix_world.inverted() * obj.matrix_world
    eul = obj_mat.to_euler('ZYX')

    vec_a = mathutils.Vector((0.0, 0.0, 1.0))
    vec_b = vec_a.copy()
    vec_b.rotate(eul)
    difference = vec_a.dot(vec_b)
    key1 = obj.data.shape_keys.key_blocks["Key 1"]
    key1.value = difference

Result of the change in the script.
Now we have to fix the rotational offset of the camera. The shapekey should extend if the camera faces the blue face. We'll compare the (transformed) vectors which we want to align. At the top of the script import the math module as well.
import math
Then turn on the axes on the objects, and choose two axes which you want to align. In my case it's the camera's negative Z (0, 0, -1) and the object's positive Y (0, 1, 0).
def drive_shapekey(scene):
    obj_mat = cam.matrix_world.inverted() * obj.matrix_world

    obj_eul = obj_mat.to_euler('XYZ')
    cam_vec = mathutils.Vector((0.0, 0.0, -1.0))
    obj_vec = mathutils.Vector((0.0, 1.0, 0.0))
    obj_vec.rotate(obj_eul)
    difference = cam_vec.dot(obj_vec)

    key1 = obj.data.shape_keys.key_blocks["Key 1"]
    key1.value = difference

The difference in initial orientation has been taken into account.
Next we are going to add the positional relation to the script. Previously, we compare a camera related vector, but now we need to compare a camera-object relation vector (on the right side).

In our case, the needed vector pointing from the camera to the object is simply the object's location (normalized). This is because the camera is at (0, 0, 0), since we earlier applied the camera's world matrix to the object and we're in camera-relative space from then on.
Now, the dot product is only 1 if the object is actually facing the camera from any position.

The completed script.
import bpy
import mathutils

cam = bpy.context.scene.objects['Camera']
obj = bpy.context.scene.objects['Cube']

def drive_shapekey(scene):
    obj_mat = cam.matrix_world.inverted() * obj.matrix_world

    obj_eul = obj_mat.to_euler('XYZ')
    cam_vec = obj_mat.to_translation().normalized()
    obj_vec = mathutils.Vector((0.0, 1.0, 0.0))
    obj_vec.rotate(obj_eul)
    difference = cam_vec.dot(obj_vec)

    key1 = obj.data.shape_keys.key_blocks["Key 1"]
    key1.value = difference

pre_handlers = bpy.app.handlers.scene_update_pre
[pre_handlers.remove(h) for h in pre_handlers if h.__name__ == "drive_shapekey"]
pre_handlers.append(drive_shapekey)

As suggest in the comments by batFINGER: Checking for the name in the second line from the end will prevent other handler to get removed.

There seems to be the need to control shapekey on multiple object (as seen in the question's edit). This isn't that difficult if the parameters are properly understood.
The lookup up name in the key_blocks 'Key 1' is simply the name of the shapekey on the object. If your shapekey has a different name, the code should be changed accordingly.

The next codeblock will update the cameraFacingKey shapekey on multiple objects: Cube and otherCube using a single method. It relies on both of them having the same shapekey name. The import and handler statements shouldn't be changed.
This code creates python list with a list comprehension. In the drive_shapekey(scene) method it loops over all objects in the objs list.
cam = bpy.context.scene.objects['Camera']
obj_names = ['Cube', 'otherCube']
objs = [bpy.context.scene.objects[name] for name in obj_names]

def drive_shapekey(scene):
    for obj in objs:
        obj_mat = cam.matrix_world.inverted() * obj.matrix_world

        obj_eul = obj_mat.to_euler('XYZ')
        cam_vec = obj_mat.to_translation().normalized()
        obj_vec = mathutils.Vector((0.0, 1.0, 0.0))
        obj_vec.rotate(obj_eul)
        difference = cam_vec.dot(obj_vec)

        key1 = obj.data.shape_keys.key_blocks["cameraFacingKey"]
        key1.value = difference

..A truly wonderful answer! Would it be possible, in principle,  to  do this in a driver, rather than have drive_shapekey called back by the scene updating? I've been trying to work out how much vector maths you can do in driver scripted expressions ..

@Robin I can't think of a way right now, the script relies on the matrix_world property, which enables it to work even if camera and/or object are in a parenting hierarchy. For a production rig don't parent the camera to anything sounds to restrictive. (I think the driver needs a different workflow.)

Very comprehensive. Adding if h.__name__ ==  "drive_shapekey" will avoid removing other handlers.  As is could be pre_handlers.clear()  @RobinBetts The use_sellf option of drivers lets you pass the object as self,  Henceforth can ref self.matrix_world  The above could be rejigged to a driver drive_shapekey(self) with cam = bpy.context.scene.camera

@Leander thanks for the comprehensive answer! It's greatly appreciated. Would it be possible for this script to work with multiple characters on the same camera? Let's say that I have "Cube2" with a shape key named "Key 2" (although I'm assuming if it was named "Key 1", this would still work because of the different path). I've moved around some variables in the code and added the modified code block to the post above. It's probably wrong because all I really did was add "2"s everywhere, but it's worth a shot.

@ItsWhy Your code example worked as expected. Nevertheless I have added a more pythonic approach and even more clarification for future readers to the answer.

This is spectacular, I'm going to make this into an addon. It would go over really well!

Using drivers you can get almost every property value from an object, so you could combine them in order obtain the relative orientation between the faces from the mutual object's rotations or position...
I think the easiest way to approach the problem is to take advantage of the Rotational Difference driver variable type, so we don't have to worry too much about the math.
Add an armature with two bones, one constraint to the transformation of the main object and one constraint to the transformation of the "camera" object.
Create the shape keys for the object and add a driver to the Factor value using the sin() function to parametrize the mutual bones rotation values between 1 and -1 like shown below:

Here's the setup in action and the blendfile for inspection:

Could you add information on how this can be avoided?

If you are interested in Z rotation only, substitute the Copy Transform constraints with a Rotation constraints for the Z rotation only, @Leander. I used the Copy Transform constraint so It would be visually easier to understand the process, but there is really no need to copy all the parameters.

Another driver approach
Using the methods outlined in Left / Right Test  Purely checks to see if camera is on left or right of an object, where local z is up and y is forward.

Result where shapekey is a simple 2x z scaling.
Copy the script below, paste in text editor and run script to register the driver.
import bpy

def drive_shapekey(name):
    cam = bpy.context.scene.camera
    obj = bpy.context.scene.objects.get(name)
    if not (cam and obj):
        print("Driver Error")
        return 0
    mw = obj.matrix_world
    loc = mw.translation
    left = mw.to_3x3().transposed()[0] # normal to the plane
    left = -left if left.x < 0 else left # flip claus
    d = left.dot((cam.matrix_world.translation - loc).normalized())

    return abs(d)

bpy.app.driver_namespace["ds"] =  drive_shapekey

In the shape key of the object you wish to drive, type in
#ds("Cube")

the hash "#" signals to blender that this is a python driver expression.

to drive that shapekey based on the left or right-ness of the object named "Cube" to the scene's camera.

Would this work with multiple meshes on one camera by running the script multiple times with each mesh's corresponding variables and adding a driver for each?

Not sure I quite get what you are asking. Really only need to run script once to add  method to driver namespace, then add driver on other fields as required.  Ideally  I'd use  this on a custom property of the object passing self to  the driver rather than  name,  Then use the  custom property as a var in  the shapekey driver or other drivers.  For simplicity, and because nothing was being modified on object being passed to driver via name. Side note taking out the abs on last line of driver could use max(0, ds("Cube") and max(0, -ds("Cube")) as left / right test

My answer is similar to Carlos.  It includes some improvements in order to address issues with the rotational difference driver type, which does not just give a straight angle like I expected :)
Even though I'm doing this with bones, I think that the better way to do this is with a script that measures the dot product between two vectors, and I hope somebody will come along and show us that script.  I don't do Python yet myself.
Okay, start by parenting your shapekeyed mesh to an empty or something.  We'll call this the global parent.  This will help us avoid dependency issues.
Next, create a new armature with 4 bones, located at the center of our cube and parented to global parent.  The four bones are baseline and track (root bones), axis and measure (both parented to baseline.)  The important things here are the tails and axes; baseline and track need to be coincident with identical roll, and axis and measure need to be coincident with identical roll, in a position orthogonal to baseline/track.
Here's a picture of my armature in pose mode, with an offset copy in edit mode:

Next we need constraints for these.  Track bone will track the camera, so we'll give it a damped track (Y axis) to the camera.  Axis needs to remain orthogonal to both track and baseline, so we'll do this by giving a locked track on our baseline bone, locking Y and pointing -z to the track bone.  Axis bone itself gets no constraints.  Finally, the measure bone gets a locked track, locking its Y and pointing its -Z at the tail of the track bone.
What we have here is a pair of bones (axis and measure) where we can measure their rotational difference and be confident that it represents only rotation in a single axis, avoiding problems that come up with using the rotational difference property on bones that might roll.  We can safely use the rotational difference property for our driver, but notice that we could as easily use the Y axis rotation of our measure bone-- our axis bone, strictly speaking, is unnecessary, but I think it better demonstrates what it is that's going on.
Time for our driver.  We want the shapekey at its maximum when the angle is at 0 degrees (0 radians) or 180 degrees (pi radians), and we want the shapekey in the range of 0-1.  You haven't specified a response curve that you'd like from this, so we'll use a sine wave, because that's easy.  If we use abs(sin(var)) here, it will give us a smooth curve that behaves as we'd like.  Note that the exact driver is visible in the picture above.


text:
How to use detailed brushes in sculpt mode without having to use multiresolution on the entire object?
In the sculpt -> retopology workflow, it is very convenient to use textures with height information to add details "creatively", meaning you can drag them around and place them where it looks best:

The issue is, that you have to apply a multiresolution modifier to the entire mesh, that you'd like to use this method on. This is not feasible in many cases, for example I'd like to use this method on a sculpt of a figure I already sculpted:

If I'd apply a multiresolution modifier, I'd quickly need more ram than Google has in their servers.
If I were to just use the brush on the existing mesh, the resolution would be too low and it would get really laggy:

Is there a way to use this creative, responsive method, with the visual feedback on a high-poly mesh? In an ideal world, only the extra geometry needed for the brush to look good would be added, which is neglible. I know an alternative is the boolean modifier, however you can't really use it with alphas, you have to go out of sculpt mode and it is equally slow.

Your best bet is to isolate the torso portion of the mesh and use the brush as required.
Then you can rejoin the torso to the entire mesh. I assume you are going to retopo it.
This combined with the mirror modifier can reduce the amount of vertices for your RAM to handle.


text:
How do I make a smooth shaded mesh not look weird?
I'm someone who wants to try and make a game and modelling is one o the aspects I'm trying to learn. I'm new here in blender and I don't know a whole bunch yet. But I'm trying to cut a shape of a lego (roblox) head:

and shading it smooth:

As you can see, the smooth shade makes the mesh look weird in some place and I'm wondering how to fix it.

Here's another picture in edit mode and yes, there are a lot of N-gons on the curves I made and I heard those make smooth shading look weird. Another thing to note is that I'm going to solidify the mesh so it doesn't look paper thin. But the result came out like this:

Here's what I did to make the shape:

I took a loop of the head, seperate it, and turned it into a curve
I modelled the curve using the edge slide tool to move the vertices on the surface of the head, return it to a mesh then join it with the head.
I then deleted half of the head and make a new vertex path for every edges that looks connected with the head and fill it.
I used the smooth shade option

Here's what I've tried to do:

Check if the vertices are on the right coordinates
Try to convert the N-gons to triangular faces
Try subdividing and converting to triangular faces

I really hope someone could help me with this, thanks!
Here's a link to my blend file (Don't mind my amateur models please!):

https://blender.stackexchange.com/questions/89/when-should-n-gons-be-used-and-when-shouldnt-they/

Sorry for the late response but thanks for the answer! Yes, N-Gons are not good for what I'm about to do (exporting after finished) which is why I'm now trying to remove them. I tried to make the whole mesh to triangles and turn them back to quads. The result in smooth shading is fairly better but the irregular shadows still appears. Any other suggestions on what should I do?

Select the object, right click and select auto smooth.

Hello! Again, sorry for the late response. I tried to use the auto smooth after but it still results on the same weird shading. Are there any other ways to fix it?

Oh. Try using a weighted normals modifer. If that doesn't work can you share your blend file?

Heya! Thanks for the help again. Unfortunately after trying the weighted normal modifier, the same weird shading still persists. Probably because I'm unfamiliar to the use of the modifier. I'll include the blend file on my edited question. Thanks in advance!

Or maybe try this:


text:
How to create this cone item in blender?
I'm pretty new to blender, but I'm done with boxmodeling. I tried to create an item of a game for my room, but I struggle a lot with it I tried it several times and in different ways but I have no clue how to do the stuff around the cone and the dark blue outside.

And this is one of my tries

Maybe I can get some help and tips?

Hi Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the [edit] link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?""

what I would do for the top point, is go into edit mode, and wire frame view, then select your knife tool, and cut a straight line just below the point, from there you can add loop cuts to play around with and round off that point. then from there I would play around with curves to get the strips around the outside, once you have what you want, add in a plane, stretch it out, then subdivide a couple times, then assign your plane to the curve.
I hope this helps out.

Thank you! I will try it this way.

To do the stuff dark blue outside the cone I will use Curves.

Thank you. That's really something I didn't work with yet >.< So I gonna try this.


text:
Haven't touched this project because it was so laggy. I managed to make the low poly the same amount as the high poly?

I suppose I overdid it with the subdivision and multi res modifiers. How can I fix it? The file is over 1kb

You said that "I suppose I overdid it with the subdivision and multi res modifiers" So did you try lowering the values?

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?""

Use a Decimate modifier on it.
The un-subdivide mode will revert the levels of subdivision if you applied a subdivide or multires modifiers:

The collapse mode will merge the faces and reduce the count while respecting the general shape of the object as much as possible:

Choose one depending on whether your object is just a simple shape that has been subdivided too many times or an object with relatively flat faces and some small detail sculpted on it.
(Planar mode does the same as collapse but with ngon faces so I don't think it's very useful)

Thank you! After I do this, would I have to do retopology again? If so, should I save the low poly into a new file after - so it's separate from the high poly model, reducing the file size?

You can take the lower res object, give it a multires mod and shrinkwrap to have the same shape as the high poly mesh:
https://www.youtube.com/watch?v=Bx835KV4aZg
But I don't see how that's going to lower your geometry count if you are still gonna add a multi res modifier to it again


text:
Rigify bones not inheriting parent rotation?
I'm working on a hair rig for my character for a game I'm designing. I've done this by adding multiple strands of bones to a Rigify armature, both front and back hair models.

Each strand is given the tail rig type and is parented to spine.006.

The problem is that after the rig is generated, when I rotate either the head or the torso, the hair rig does not rotate along with the spine. How can I resolve this problem.

Don't forget CTRL + A Apply all transforms to reset the position and rotation.

I had this issue today and found a solution. My rig has multiple tail bone sets parented to the head like this example, and once generated you need to select the master controls of each tail and set Tail Follow to 1, it seems by default the tails do not automatically follow. In addition I just tested it and this resets if you regenerate the rig.

I had to change the bones rig type to limbs.simple_tentacle.

It's good that you found a solution but I don't think the rig type was the problem. Tail should also follow the parent...


text:
Strange shading fragments on mesh
can anyone help me?
I've just finished texturing a model I made. After I import the mesh and the textures in UE4, I've encountered this shading fragments.
This are screenshots on UE4:

This is how it looks like in substance painter:

And this is the model on blender:

EDIT:
I'm not too sure with the all quads solution.
I've tried ripping a part of the model that is all quads but it's still giving me weird shading.
New blender screen capture:

They all appear where there are tris so you should try to make all quad base geometry

All quads? Alright. I'll try that. Thanks.

Some of the fragments were removed when I made the edges sharp and added an edge split modifier then baked the normals using that mesh as the low poly. But some of the fragments are still there, so I'm going to try making those parts quads

If you have a simpler version with everything quad, maybe you can try this: https://www.youtube.com/watch?v=3rlMzsBWtPY

A possible solution to your question could be that you need to try and make geometry that defines the shape of your  all quads and then, around corners, add edge loops to surround those defining points (namely sharp corners, etc.). Then, after that, mark those edges (not the esge loops) as creases. It should work after that. Using a subsurf modifier should help on top of this.

Normal baking is complicated thing. I'm think, usually your Low-poly must good look wihout normal map before baking. Not have bad shading. So you can for example add some bevels or sharp edges as you wrote. Also try to make quads flat in problem areas.
 You can check out this: https://polycount.com/discussion/81154/understanding-averaged-normals-and-ray-projection-who-put-waviness-in-my-normal-map

Instead of using edge loops or setting edges to sharp, use the auto smooth auto smooth option and set to angle to ~80 degrees. This should help with the weird shading artifacts.


text:
How can I create sets of orthogonal rings on a sphere that I can extrude inward?
I'm trying to make grooves on the surface of a sphere.  I can make one set of grooves by making a UVSphere with many rings, and then extruding every third or fourth ring inward individually.  However, I also need to extrude a set of rings that are orthogonal to those, like rotating the sphere 90 degrees and doing the same.  I can't just do it that way because the UV sphere is made with segments instead of an orthogonal set of rings.  If not a full solution, I am hoping at least for some ideas.  I also have learned how to make a sphere out of only quads by turning a subdivided cube into a sphere, but then there are no rings to use.

90 degrees on which axis?  You might be looking for some impossible contours, because you can't tile a sphere with a grid. So, your lines will always come to a point on one axis, like the UV sphere. Maybe find an image of what you are trying to achieve?

Try an Ico sphere with a subdivision surface.

Why is this tagged with Python, are you looking to achieve this through scripting?

I think Carlos's solution is exactly what I need.  I tagged python because at some point I'd like to be able to make it with Python so I can modify it easily.    Thanks everyone.

Use Booleans
I can't think of a topology that has the loops that you describe ready to work with.
So, depending on your project needs, I would advice to try other ways of modeling your object.
For example you could take advantage of booleans in the exact way you described.
In the main object extrude inwards the edgeloops of a sphere, then duplicate and separate those faces in another object.

Rotate the object on the Y axis by 90°, re-extrude the faces to build a watertight mesh and use it as target for a Boolean modifier to carve the grooves in the other direction while maintaining a certain degree of felexibilty in the modeling

Final result:

This is the first time I have seen anyone fit a square hole into a round peg...


text:
The correct Node workflow?
I stumbled upon this link which depicts the workflow for creating materials in Houdini.
Material Studies: Metals
How would you approach this workflow in Blender ?
Thanks!

Use the Principled shader with metalness all the way to 1.0. Just input those values into it and that's all. If you want a metal shader more accurate see this: Conductive Fresnel

https://blender.meta.stackexchange.com/questions/2449/what-is-the-problem-with-posting-an-image-or-link-and-asking-how-do-i-do-this

Thanks for the answer, i will get into it! @JaroslavJerrynoNovotny

I asked about a workflow which is complex and general, i didn`t ask "how i create iron mat" so yea, uncalled for on that one. :) @DuarteFarrajotaRamos

@Occultcg There's nothing wrong with asking "how to create iron mat", or "how to replicate this workflow", but please take the time to read the suggestions here. Adding some description of the content of the link — or better yet, what you've tried and what hasn't worked — will increase your chances of getting an answer.

Ok i will take that into account in the future, thanks for the tips! @gandalf3


text:
Geometry nodes: Taking attributes from parent object
Is there a way to take a value from a parent object for use in an embedded geometry node?
For example I have a geometry node which generates a city block which has an group input parameter that sets how many buildings I want in a row.
If I embed this geonode inside a plane, for instance, is there a way I can set it up so that the width of the plane can be used to determine how many buildings I have in a row rather than having to manually input the value?
I would calculate the number of buildings by dividing the width of the plane by the width of a building. But I don't know how to do this in terms of Geometry Nodes.
How do I extract the width of the plane and the width of the building (which is in a collection of similar buildings) in order to divide them?

excuse my ignorance, but I cannot see the problem. The plane knows its width. If you also have the width of one building then plane width / width of building = number of buildings, right?

Yes, but I dont know how to do this in terms of geometry nodes. How do I extract the width of the plane and the width of the building (which is in a collection of similar buildings) in order to divide them?

Oh, I see. You can get the dimensions of the plane with the Bounding Box node. Then use a Vector Math node (Subtract) to calculate Max-Min = dimensions. But I don't know how to get the dimensions of the instances in a collection.

Here is something similar but the example doesn't use collection. It uses the Accumulate Field node to stack scaled objects: https://youtu.be/kiSi0HC7-aM?feature=shared (5 parts)


text:
2 problems. One, my left leg armature moves my entire body, and when i tried to fix it i couldn't see my vertices
I'm quite a beginner in blender, I don't really know alot about bones and armature, so I made it with the skin modifier witch I have since applied. Basically I need to know how i can see my vertices and then fix the bones.
No vertices:

Leg bone:

Are the vertices in question the vertices on your model? If so, go into object mode, select your character then go back to edit mode. It looks like currently you are in the edit mode of your armature.

pls provide blend file

I tried to do that but, after a while my blender gets so laggy i can't tell if i've selected something. I guess i didn't notice, thanks.

@Chris

if you change viewport display to octahedral ...

you can see the reason:

your leg bones have the wrong direction, so select these bones in edit mode and choose armature -> switch direction

after that you have to correct the parenting like this:
select the child bone, then the parent bone, then press CTRL-P -> connected

Thank you so much! I've looked in so many places and couldn't find the answer.

You are welcome


text:
Why is my texture not showing correctly?
I am still learning blender and I followed a tutorial that adds textures. I followed it step by step but my texture just won't show correctly.
Am I missing something super obvious?

https://ibb.co/9grsrzg

Are the meshes UV mapped?  That may be the super obvious thing getting missed.

Have you applied the scale to your objects? Also read up on unwrapping UVs.

how can I check that?

open the UV Editor and select a whole mesh in Edit mode in order to see the UVs

Check that you are showing the render view not the lookldev view, try cycles renderer.  As others have suggested, Object -> Apply all Transformations, redo the UV Map and scale it in the UV editor.  Also enable 'Face Orientation' in the Viewport Overlays to make sure your 'floor' is blue not red.  If it is red, flip the normals on that object.

@JannisN Please do not link external images but use the image upload function of BSE and add them directly to your question.

My guess is that if you don't know how to check the UV map, then you most certainly did not unwrap. For a start, select the whole object in edit mode, press U (unwrap) and select "cube projection". This is not a perfect method, but it will at least let you see your textures, and you will actually have some shapes on your UV map to play with. For a more in depth (and I mean really in depth) description of UV's and how they are used, see here. It's long, but complete - https://artisticrender.com/the-definitive-tutorial-to-uv-mapping-in-blender/


text:
How to easily create and deform multiline wires?
Thanks a lot in advance for any suggestion you could provide for this topic:
I am modeling a robot with servomotors, and all the servomotors have 3-line wires (a red line for input voltage, a black line for the ground, and a yellow line for control pulses), as shown in the picture (the black boxes are the servomotors):

Currently, I am modeling each wire separately as a bezier curve. But it is time consuming to route the wires separately through the body of the robot because I have to do it 3 times (for each different wire) and I have to make them fit together through the route as if they were attached together.
My question is: How can I create a 3 wire structure like that (3 wires of a different color) and move and edit them as if it was a single wire?

Maybe try the Hook solution? Hook the curve vertices to an empty:

Now another solution that doesn't fit your needs as your curve have different colors:
Create your curve. Create its profile (create a Curve > Circle, duplicate it in Edit mode). Select the curve, in the Properties panel > Object Data > Geometry > Bevel, click on Object and choose the 3 circle curve as Object:

Thank you Moonboots. I have already tried that, but I can´t select a different color for each wire (unless I convert to mesh the wires, but in that case I loose the bezier advantage).

oh ok sorry, maybe hooks then?


text:
Problem with my tiny icing particles on the donut
I'm a complete noob to 3d software. I took the Blender Guru's tutorial and finished it once before. Now I am doing it again but by myself going back to things I found hurdles in, ie the geometry node segment.
My problem is that the cylinder is appearing but they are microscopic. Any ideas would be appreciated. Thank you.

Its likely that the problem here is that the cylinder has been scaled and that scale has not been applied. Select the cylinder, press CTRL-A, and select "Scale"

Hopefully that will fix it, You could also check the relative box on the object info node but that will take into account the position of the cylinder as well so you'd have to move it to the origin.

i applied the scale and it gave me the image i showed  i think the problem was i went into shading  and applied some nodes to the icing ? im really lost so far it looks good but the sprinkles are a kill joy

You could try applying the scale on the donut as well in case that is off. I wouldn't expect it to be a shading issue since your screenshot shows the problem in solid view and a shading issue would only appear in rendered or rendered preview.

YOU ARE A GOD THANK YOU SO MUCH

@AustinMgbolu If the answer was helpful please accept it or upvote useful answers. This helps other users that have a similar question to find a solution for their problem.

What @Stoat Paws mentioned is likely the solution, also it's possible that you're modeling your donut at an enormous scale. Make sure that the object dimensions resemble something like a real life size for both the donut and the sprinkles, or at least something realistic relative to eachother.

That or check the scale value in the particle system if that's how you're distributing the sprinkles.