Camera Culling Operator

Path

 

Particle View > Click Camera Culling in an event or add a Camera Culling operator to the particle system and then select it.

 

Camera Culling reduces the geometry load in the viewports and/or at render time by filtering out all particles outside the camera frustum (that is, not visible to the camera). The operator can be used as a group selection tool to define a group by the camera view frustum.

 

 

Interface

 

 

 

Use Active Camera - When on, uses the camera assigned to the active viewport. When off, you can assign a different camera to the operator for frustum culling. Default=on.

 

Camera - Lets you specify the camera to use for culling particles. Click the "None" button and then select a camera in the scene to use for frustum culling. Thereafter the camera name appears on the button. Available only when Use Active Camera is off.

 

 

Clipping Planes group

 

These controls let you define "near" and "far" planes to remove particles that are too close to or distant from the camera. If particles are small and far away, they might not be visible in rendered output, but if they are not clipped their geometry is added to processing for the render. You can use existing camera clipping settings or define them here.

 

Use Camera Clip. Planes - When on, uses the camera’s clipping planes as defined in the camera controls: Modify panel > Parameters rollout > Clipping Planes group. The result will depend on the following camera settings: Clip Manually, Near Clip, and Far Clip. When off, the operator uses the following settings to define the clipping planes.

 

Near Clip - The option is available if Use Camera Clip. Planes is off. When the Near Clip option is on, all particles that are closer than the Near Clip value are excluded from rendering.

 

Far Clip - The option is available if Use Camera Clip. Planes is off. When the Far Clip option is on, all particles that are farther than the Far Clip value are excluded from rendering.

 

 

Cull By - This option lets you specify which part of the particle is used to determine whether or not to cull it. The available choices are:

  • Particle Pivot - The decision to include or exclude a particle from render is based on the location of the particle pivot point only. Thus, a particle's geometry could be partly inside the camera frustum, but as long as the pivot is outside it, the particle is not submitted to the renderer. The shape, size, and orientation of a particle do not matter.
  • Bounding Sphere - A particle is used for rendering if any part of the bounding sphere is within the camera view. Besides the position, particle shape and size does matter here.

 

Camera View Frustum Culling group

 

These controls let you specify whether to cull particles in the viewports or when rendering, or both (or neither).

 

Render - When on, the operator culls particles outside the camera view frustum at render time.

 

Viewport - When on, the operator culls particles outside the camera view frustum in all viewports.

 

 

Use For Group Selection - When on, the operator defines a selection group by using the geometry of the camera view frustum and particle position. It works in a manner similar to the Group Selection operator. Particles designated in this way can then be submitted to the Display Script, Group Operator, or Split Group actions.

Note: The Group Selection option can work only if you have Particle Flow Tools®: Box#1 installed in your system (commercial or demo version).

 

Inside Camera Frustum - All particles inside the camera view frustum are selected for group operation.

 

Outside Camera Frustum - All particles outside the camera view frustum are selected for the group operation.

 

Subframe Precision - When on, the operator calculates the time of entering or leaving the camera frustum with increased precision. The precise time can be important if the group selection data is used by the Split Group test from Particle Flow Tools®: Box#1.