Abstract base class for 3D particle collision shapes affecting [GPUParticles3D] nodes. Particle collision shapes can be used to make particles stop or bounce against them. Particle collision shapes work in real-time and can be moved, rotated and scaled during gameplay. Unlike attractors, non-uniform scaling of collision shapes is [i]not[/i] supported. Particle collision shapes can be temporarily disabled by hiding them. [b]Note:[/b] [member ParticleProcessMaterial.collision_mode] must be [constant ParticleProcessMaterial.COLLISION_RIGID] or [constant ParticleProcessMaterial.COLLISION_HIDE_ON_CONTACT] on the [GPUParticles3D]'s process material for collision to work. [b]Note:[/b] Particle collision only affects [GPUParticles3D], not [CPUParticles3D]. [b]Note:[/b] Particles pushed by a collider that is being moved will not be interpolated, which can result in visible stuttering. This can be alleviated by setting [member GPUParticles3D.fixed_fps] to [code]0[/code] or a value that matches or exceeds the target framerate. The particle rendering layers ([member VisualInstance3D.layers]) that will be affected by the collision shape. By default, all particles that have [member ParticleProcessMaterial.collision_mode] set to [constant ParticleProcessMaterial.COLLISION_RIGID] or [constant ParticleProcessMaterial.COLLISION_HIDE_ON_CONTACT] will be affected by a collision shape. After configuring particle nodes accordingly, specific layers can be unchecked to prevent certain particles from being affected by colliders. For example, this can be used if you're using a collider as part of a spell effect but don't want the collider to affect unrelated weather particles at the same position. Particle collision can also be disabled on a per-process material basis by setting [member ParticleProcessMaterial.collision_mode] on the [GPUParticles3D] node.