A restitution of 1.65 means that an object would gain energy by bouncing. It would leave the surface it impacts with a velocity higher than it entered.
This is really bad for the stability of the physical simulation, so it seems very reasonable to cap this value.
if you need to give an object an extra “kick,” you can always register a collision callback and add a force to it.
Hi
Since 4.12 or 4.11, the Physics Material Restitution value is capped at 1.0 in the editor.
I used to use it with something like 1.65 which doesn’t work anymore since I upgraded.
Could you advise how to be able to break that cap? It used to work just fine over 1.
That’s what I ended up doing but in the case of an older pinball-type game I had in 4.10, the restitution >1 worked wonders. I admit it’s not physically correct maybe, however it sure was lighter than having to flip a vector and apply force.
I’m currently working on physical materials and encounter this old issue.
It occurs to me that we can set restitution larger than 1 with editor utility blueprint.
(This is unstable and just for fun)
Actually, the limit of resititution only exists in the detail panel of editor. It comes from the metadata of UPROPERTY, and we can set any value with blueprint/c++.
source code: PhysicalMaterial.h
/** Restitution or 'bounciness' of this surface, between 0 (no bounce) and 1 (outgoing velocity is same as incoming). */
UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = PhysicalMaterial, meta=(ClampMin=0, ClampMax=1))
float Restitution;