Applyng Metaball nonuniform Scaling regresses to uniform #124319

New Issue

Philip-Schroeder · 2024-07-07T22:25:08+02:00

Philip-Schroeder commented

2024-07-07 22:25:08 +02:00

System Information:
Ubuntu 24.04 LTS x86_64
Graphics Card: NVIDIA GeForce RTX 4060

Blender Version:
Broken: 4.1.1 Release
Worked: -

Short description of Issue:
When scaling metaballs not on all axes at the same time (nonuniform scaling) and afterwards applying the scale,
the scaling would switch to a uniform scaling distorting the metaball.

Exact steps for others to reproduce the issue:

Happens with all kinds of metaballs and multiple scalings. just mentioning simple example.

Press Shift+A -> Mataball -> Ball
Press S+x while metaball is selected.
Scale metaball an arbitrary amount, so that it becomes an ellipsis.
Press Ctrl+A -> Scale.
The metaball will regress to a ball again.

Additional Information
The reason will most probably be that in source/blender/blenkernel/intern/mball.cc ,
function BKE_mball_transform scale is just a single float value instead of a matrix or a quaternion.

**System Information:** Ubuntu 24.04 LTS x86_64 Graphics Card: NVIDIA GeForce RTX 4060 **Blender Version:** Broken: 4.1.1 Release Worked: - **Short description of Issue:** When scaling metaballs not on all axes at the same time (nonuniform scaling) and afterwards applying the scale, the scaling would switch to a uniform scaling distorting the metaball. **Exact steps for others to reproduce the issue:** Happens with all kinds of metaballs and multiple scalings. just mentioning simple example. 1. Press Shift+A -> Mataball -> Ball 2. Press S+x while metaball is selected. 3. Scale metaball an arbitrary amount, so that it becomes an ellipsis. 4. Press Ctrl+A -> Scale. 5. The metaball will regress to a ball again. **Additional Information** The reason will most probably be that in _source/blender/blenkernel/intern/mball.cc_ , function _BKE_mball_transform_ scale is just a single float value instead of a matrix or a quaternion. ![image](/attachments/99c00d62-5ac4-4f4e-88c9-eb874e6a4125)

image.png

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Philip-Schroeder added the

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Design

label 2024-07-07 22:25:08 +02:00

Philip-Schroeder added this to the Modeling project 2024-07-07 22:25:08 +02:00

Hans Goudey added

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labels 2024-07-08 16:10:08 +02:00

Pratik Borhade commented

2024-07-09 08:03:55 +02:00

Hi, thanks for the report. Can confirm

Pratik Borhade added

and removed

labels 2024-07-09 08:04:10 +02:00

Philip-Schroeder commented

2024-07-11 22:11:44 +02:00

Hello, thank you for triaging my issue.
As I need it quite urgently, would it be ok if I would implement it myself?

As I am new, what would I have to do for that?
Normally I am used to opening a feature-Branch and then after finishing it, creating a pull request to merge into develop.
What we are using at work is basically GitFlow, like this:

https://nvie.com/img/git-model@2x.png

But I was told, in OpenSource repositories I might not have commit rights on the upstream server, not even on my own feature branch.
Therefore I should probably create a fork of the blender-repository and create my feature-branch from that.

Please confirm the process or tell me where I am wrong.

On a side note, I would also like to integrate the procedure into the developers handbook,
probably here in "Guidelines":

https://developer.blender.org/docs/handbook/contributing/#guidelines

Maybe I am missing something but it seems to tell me a lot about commit messages and not how to format the pull requests and so on, but not how to actually start with a new feature, issue or hotfix. Also for people who might not be already into the collaboratoring process that much, maybe an explanation of what a pull request is to begin with, and why we need it and stuff like that would be nice.
The current Guideline look more like a storage tank for different rules than an actual guide.
Hope I have not offended anyone by stating that.

Therefore my suggestion would be that I could document the process in a different feature-branch while I am going through the process for others to have it easier.

Hello, thank you for triaging my issue. As I need it quite urgently, would it be ok if I would implement it myself? As I am new, what would I have to do for that? Normally I am used to opening a feature-Branch and then after finishing it, creating a pull request to merge into develop. What we are using at work is basically GitFlow, like this: https://nvie.com/img/git-model@2x.png But I was told, in OpenSource repositories I might not have commit rights on the upstream server, not even on my own feature branch. Therefore I should probably create a fork of the blender-repository and create my feature-branch from that. Please confirm the process or tell me where I am wrong. *************************************************************************************** On a side note, I would also like to integrate the procedure into the developers handbook, probably here in "Guidelines": https://developer.blender.org/docs/handbook/contributing/#guidelines Maybe I am missing something but it seems to tell me a lot about commit messages and not how to format the pull requests and so on, but not how to actually start with a new feature, issue or hotfix. Also for people who might not be already into the collaboratoring process that much, maybe an explanation of what a pull request is to begin with, and why we need it and stuff like that would be nice. The current Guideline look more like a storage tank for different rules than an actual guide. Hope I have not offended anyone by stating that. Therefore my suggestion would be that I could document the process in a different feature-branch while I am going through the process for others to have it easier.

Pratik Borhade commented

2024-07-12 09:50:14 +02:00

Hi, first you'd need to setup blender to build locally. For that, refer: https://developer.blender.org/docs/handbook/building_blender/
Re pull request workflow, you would have to first fork the main blender repo then you can create and push commits on "feature" branches. More info at: https://developer.blender.org/docs/handbook/contributing/pull_requests/

Also see for general info for new code contributors: https://developer.blender.org/docs/handbook/new_developers/

Since this is about transform code, @mano-wii might able to help here. If in doubt, feel free to ask in modeling-module

Hi, first you'd need to setup blender to build locally. For that, refer: https://developer.blender.org/docs/handbook/building_blender/ Re pull request workflow, you would have to first fork the main blender repo then you can create and push commits on "feature" branches. More info at: https://developer.blender.org/docs/handbook/contributing/pull_requests/ Also see for general info for new code contributors: https://developer.blender.org/docs/handbook/new_developers/ Since this is about transform code, @mano-wii might able to help here. If in doubt, feel free to ask in [modeling-module](https://blender.chat/channel/modeling-module)

Philip-Schroeder commented

2024-07-13 13:17:07 +02:00

Hello, thank you for clarifying. I have already read the developer handbook, as you see that I was referring to it in the above post, and built blender. So it seems I need to work with forks and do not have commit rights on the original repo. Thank you, that was what I wanted to know. I will create the respective feature branches and get back to you once I am finished for the PR.