rigidBodies moving too slow

# 1 24-04-2012 , 01:08 PM

Registered User
Join Date: Jan 2005

Location: vienna

Posts: 1,095

Hi there!

I have a question concerning the animation speed of a rigid body simulation.

scene:
a box full of balls. one side of the box opens and the balls start rolling out on the floor and away.

now, when I run the simulation with "play every frame" (cached) everything looks natural. but when I switch back to real-time 25 frames the whole animation appears to be in slow motion.

question:
How can I increase the animation speed of the balls? I´ve already played around with the rigid solver settings (I don´t need inital speeds and spins!), but nothing makes a difference. friction and damping is already at zero. or is it the usual workflow to render just every 2nd or 3rd frame after the simulation is done? - which would be sad because I have interacting characters and animated objects in the scene and all should look quite natural...

plz help
thx!

everything starts and ends in the right place at the right time.

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# 2 24-04-2012 , 01:23 PM

EduSciVis-er
Join Date: Dec 2005

Location: Toronto

Posts: 3,374

As far as I know, 'play every frame' has no real timing relevance. It's just to make sure the sim works properly. Definitely playblast the animation to make sure you're getting true 25fps. If it's too slow, check the units of the scene. I think rigid body sims rely heavily on gravity (9.8 m/s/s) and so if your scene is actually tens or hundreds of meters wide, it will be more like dropping the times square ball. (no, I couldn't think of a good comparison).

-stwert

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# 3 24-04-2012 , 01:41 PM

Registered User
Join Date: Jan 2005

Location: vienna

Posts: 1,095

thx for your answer.

hm.. I have real world scaling here. scene units are "cm". the box is a bout 50 cm square and the balls are quite big for testing (about 10 cm). when I make the spheres smaller to like 1 cm they start sticking to the passive objects.. I cant understand whats going on. btw - all objects are medium to quite high resolution.

EDIT:

issue solved:

I tried your suggestion about scene units and upped the gravity field´s magnitude from 9.8 to 980. all looks good now.

big thanks again for your hint!!

everything starts and ends in the right place at the right time.

Last edited by Falott; 24-04-2012 at 01:44 PM.

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