Real-time heightmap-shaped 3D particle attractor affecting [GPUParticles3D] nodes.
Heightmap shapes allow for efficiently representing collisions for convex and concave objects with a single "floor" (such as terrain). This is less flexible than [GPUParticlesCollisionSDF3D], but it doesn't require a baking step.
[GPUParticlesCollisionHeightField3D] can also be regenerated in real-time when it is moved, when the camera moves, or even continuously. This makes [GPUParticlesCollisionHeightField3D] a good choice for weather effects such as rain and snow and games with highly dynamic geometry. However, since heightmaps cannot represent overhangs, [GPUParticlesCollisionHeightField3D] is not suited for indoor particle collision.
[b]Note:[/b] [member ParticleProcessMaterial.collision_mode] must be [code]true[/code] on the [GPUParticles3D]'s process material for collision to work.
If [code]true[/code], the [GPUParticlesCollisionHeightField3D] will follow the current camera in global space. The [GPUParticlesCollisionHeightField3D] does not need to be a child of the [Camera3D] node for this to work.
Following the camera has a performance cost, as it will force the heightmap to update whenever the camera moves. Consider lowering [member resolution] to improve performance if [member follow_camera_enabled] is [code]true[/code].
Higher resolutions can represent small details more accurately in large scenes, at the cost of lower performance. If [member update_mode] is [constant UPDATE_MODE_ALWAYS], consider using the lowest resolution possible.
The collision heightmap's size in 3D units. To improve heightmap quality, [member size] should be set as small as possible while covering the parts of the scene you need.
Only update the heightmap when the [GPUParticlesCollisionHeightField3D] node is moved, or when the camera moves if [member follow_camera_enabled] is [code]true[/code]. An update can be forced by slightly moving the [GPUParticlesCollisionHeightField3D] in any direction, or by calling [method RenderingServer.particles_collision_height_field_update].
Update the heightmap every frame. This has a significant performance cost. This update should only be used when geometry that particles can collide with changes significantly during gameplay.
