[SOLVED] Collision doesn't work for 'Length' particles

[ashwin.sudhir]

Collision doesn't seem to work for Length type particles. The particles boundaries don't collide correctly even after checking the 'Collision' box(looks like collision still happens with particles center), PFA blah.node sample system. When I change particle type to Billboard, collision works just fine.

 

Thanks,

Ashwin.

[manguste]

Length particles calculate collisions by their center no matter what flag is set (Collision or Intersection), because they are always stretched along their velocity vector. If a length particle hits an obstacle, it would reorient itself along a new vector which will create flickering (X-shaped like). That is why collision by particle center is only available for them.

[ashwin.sudhir]

I have a couple of gripes about this.

1. This gotcha couldn't be found anywhere in the documentation, and hence left me wondering why collision wasn't accurate and had me wasting a lot of my time figuring this out.

2. The Collision and Intersection checkboxes should have be disabled for length type particles so that this error is not made.

3. What if I have Culling on? In that case I don't care how the 'Length' particles orient after collision, but for really long particles colliding with particle centers looks really odd (we are creating sparks on collision). Can we please have true collision for length particles in an update (at least for the case where 'Culling' is on)?

[manguste]

Our developers promised to add collision by the bounding sphere available for length particles no matter what the orientation is. Will be available in the next update. But it will really look bad without culling.

[ashwin.sudhir]

I understand the problem without culling. But this is awesome! Thanks :)

[manguste]

Already done :)