Box Collision vs Static Mesh simple collision (the static mesh is a box)

Development Programming & Scripting
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1

HI,

for my flamethrower effect I wanted to use a collision that would scales over time in the forward axis (X)

I can use a Box Collision positioned at the edge of a scene component:

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or a static mesh that would just be a box with the origin on one face (-X axis), so that it scales in the other direction. It would use simple collision that would be added in the Static Mesh editor.

Which is more performant?

2

What this effect is for? Best performance is GPU collision (not sure how it changed in ue5).

This may give some ideas. Ages ago (for ue 4.12) i made flamethrower weapon:

  • used GPU collision (that was whole reason for flamethrower), however back then if something was not rendered it did not collide with gpu collision
  • then i added fire/stream of burning particles in general direction of flamethrower
  • when particle collided with floor or wall i spawned burning napalm particle that was stuck to surface for few sec (short life span)
3

GPU collision? I thought all collision was CPU based.
What I do is lerp the scale of the collision box between 1 (default) and the target scale. Then I pass this variable to the niagara so that the GPU particle travelled distance in the X axis follows the collision box.

Still, the question is what is more performant, a box collision object or a static mesh object with simple collision (not complex collision).