I did in 3ds max simulation of solar panel which are trying to orient perpendicular to direction of the sun but only to the extent that they cast no shadows on each other.
I did this with use of massFX but simulation is unstable and everything is selfpenetrating.
There will be a lot of such panels, and the time they start rotating should be delayed for each panel...
And of course at some point the direction of the sun will start to change...

I'm trying to do this in Houdini with RBD Bullet solver but I think I need to study Houdini a bit more
Maybe some suggestions?
For example, I can't force the RBD angular constraint to work with an animated geo. It works with active dynamic objects but not with static animated objects.
Maybe there is another way to lock orientation of dynamic object to animated geometry?
Maybe I should use constraint network or somethig?

hi - I make a test setup (no RBD sim)




the panels look at at the Sun
and if a Panel get hit from a Ray of an other Panel - the rotoation stops

Thank you very much
Now I have to spend some time to figure out what's going on here...