Hello, looking for some help. I’ve just started the Blender 4.0 Visual Effects course but I’ve already run into a problem. It’s for Lesson 1.8. Most of the boxes act as expected with the active rigid body physics applied but after adding a third row there are a few that seem to have their own agenda. Video linked here.
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Hi, yes it look wacky, can be a bug in Blender.
This shooting of the cubes is probably caused by the invisible cube boundaries to close to each other. Which is strange because visually they have enough room.
Each object has this boudary (forgot its originale property name) maybe something wrong there.
And maybe (while experimenting) you’ve added a (invisible) force field?
Try to remove the erroneous cubes and replace them (copy paste).
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It may be the extras are just making your computer struggle.
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@np5 I’m using an 2025 Asus Rog 18 laptop with 64 GB of RAM and Intel Core Ultra 9 275HX. I assumed that would powerful enough to handle some pretty meaty simulations, and I also assumed this introductory exercise was a relatively light sim. Am I mistaken in those assumptions?
@FedPete I also wondered if I had a leftover force field from earlier in the course, so I created a new Blender file and the problem persisted (in the original file, the problem was happening with more of the cubes). If it’s a boundary issue, I hope someone knows the property I can identify to troubleshoot this. If it’s a bug with Blender, well dang…
Here are my Blend files, if it will help diagnose the problem.
Before Error (before adding the third row of cube)
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If you remove this running puppet then the problem is gone.
So this puppet has some constrain (physics attribute) attached to it.
Probably add the puppet and scaled/moved/ relocated it from its main center point.
I think the goal is that this puppet hits these falling blocks …?
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Thanks FedPete, you’re right, it only happens when the character has the “animated” setting checked.
Actually, when I watch the instructor’s video very closely I realize that the same thing is happening in his simulation. What the heck? Apparently it is an issue with the software, even persisting when I open the file in Blender 5.0.
I wonder why the instructor wouldn’t address this during the presentation. This seems to be a major issue that ruins the simulation. But I guess I’ll move on to the next lesson as there doesn’t appear to be anything I can do about it.
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Okay, the way to avoid the problem is by changing the Collisions type on the figure mesh from Convex Hull to Mesh. EDIT: Nevermind, that actually didn’t work. DOUBLE-EDIT: It does work in Blender 4, it doesn’t work in Blender 5.
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There can be ‘breaking’ changes with the past when Blender has a major update, a full number. So that can make sense.
Never rush to upgrade. Especially main Updates.
It may be a bug, It may be a result of some change and it will take time for it to be ‘discovered’ and the ‘new way’ found out. Or a bug fixed.
Thanks, yeah I am using 4.0 for the course since that’s what the instructor is using, but I had opened the file in 5.0 just to see if the issue I was encountering was version specific.
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