1
$\begingroup$

I have tried to reduce the margin. I have tried to update Blender and tried older Blender versions. I'm trying to get my sphere to touch the ground after it bounces off the plane and comes back down. I have tried to change the Collision Shape from Convex Hall to Mesh as well which does not make much sense to me as the sphere option is already there in shapes. Can someone please help me get this problem solved?

First Bounce: First Bounce:

Second Bounce: Second Bounce

Blender settings for ball: Blender settings for ball:

Blender settings for box: Blender settings for box:

$\endgroup$
3
  • 1
    $\begingroup$ did you apply scale? if yes, pls provide blend file $\endgroup$
    – Chris
    Aug 16, 2022 at 3:02
  • $\begingroup$ @Chris Screenshot for ball settings: Scale 1/1/1; screenshot for box settings: Scale 1/1/1. $\endgroup$ Aug 16, 2022 at 11:51
  • $\begingroup$ Have you made the changes on both the sphere and the plane? $\endgroup$ Aug 17, 2022 at 19:51

1 Answer 1

1
$\begingroup$

The ball has a Collision Margin of 0.04 as well as the box. I would set them to 0. Apart from that, with simple shapes like boxes and spheres the rigid body simulations are more accurate and faster to calculate if you set the Shape to Box resp. Sphere instead of Mesh.

Another problem could be, especially on faster moving objects, that Blender needs to calculate more steps in order to not "miss" anything, for that you could increase the values for Substeps per Frame and Solver Iterations under Scene Properties > Rigid Body World. Just be aware that in most cases the simulation can look quite different if you change these values, and going too high might even make it worse at some point.

solver iterations

And then there is just one simple thing with which none of these solutions can help: depending on the overall speed of the animation (Output Properties > Frame Rate in fps, the Rigid Body World > Speed setting, the speed of the ball relative to the height from which it falls etc.), it is simply possible that the ground hit is exactly between two frames.

For example: I moved the ball manually "somewhere above the box", resulting in a Z value of 6.83874 m. The output framerate is at the default 24 fps. Simulating this, the ball does not really touch the ground, on one frame it's still coming down, the next one it's already going up.

Just moving the ball a little further down (Z value: 6.71626 m) and simulating again, it now (almost) touches the ground, just because the timing is a little bit different.

Or leaving it at the higher starting point and now setting the output to 120 fps, the ball takes a lot more frames to come down of course since it's a five times higher framerate, but now the ball definitely touches the ground before going up again.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .