For fun and learning stuff i thought i would recreate a C4D
tutorial in Blender. The tutorial is made by Roger Kilimanjaro.
Recreating the floor with the hole(boolean) was ofc easy as cake but
in c4d he animated the boolean and it interacts with the boxes that fall down.
I could not find a way to do this. When i move the boolean it does not interact with the physics.
If i apply the boolean and use AnimAll to animate the vertices so the hole moves it still
wont interact correctly. I have tried all collission types/shapes etc.
The only way that did kind of work is moving the floor with 0 friction but that only works with one box becouse else they start to slide apart.
Is there a way to make it work before spending more time with trial and error ?
I would think you’re going to have tons of trouble trying to do something like this. And I can’t think of any reasonable situation where a non-rendering collision mesh wouldn’t be a better solution. My own playing around for five minutes makes it seem like, yes, it can read an animated, live boolean operation, but that it is a very tricky thing, something it was never designed for, and it’s’ going to get screwed up.
If you want to continue to play with this, I can at least limit the number of things you’d have to be trying-and-erring:
On a concave collider, you absolutely need to use mesh collision type-- nothing else will do. Anything with a hole is concave. (Unfortunately, mesh collision is also not very reliable.) And you need to be setting the Source for the shape as “Final”.
When playing with primitives, people (incl. me) like to scale in object mode. That doesn’t work with physics. All physics (including passive/animated colliders) must have all scale applied or ti won’t work right.
Blender is not very good at knowing when its rigid body cache is out of date, and it has really piss-poor cache tools. (This is one of the places where Blender’s user friendliness is like a four year old happily shouting, “I’m helping!”) In particular, moving a boolean target won’t clear your cache. You need to reset your cache manually after most operations. You should be able to do this by moving a rigid body in object mode. (Why is there no clear cache operation? Why is there no way to tell Blender to please not cache while I do editing and testing? I don’t know.)
Thanks for testing this. From what you wrote i think the cache thing is what mucked it up for me as
i got inconsistent result when trying things. I kind of gave up on the boolean hole, i will do my own version with something else.
I “discovered” why things have not been working for me.
In the same scene i have added and removed
alot of physics releated stuff thinking when i deleted it, it would be gone. After getting alot of wierd
results i went into “blender file” tab and everything was still there. When i started to delete those things
the physics seems to work again i think…
Is this normal and is it something i should have known about from the start or is it special case with my scene ?
I literally spent hours trying to figure out why what i did was not working and the only reason
was that hidden objects i thought i deleted was still there. The only way to delete the items was in the Blender File tab. I hope someone else can benefit from knowing this… Or mayby i was just newbie that did not know