CameraCulling

CameraCulling

Command Index · Blitz3D · Cameras

CameraCulling:Void camera:Int32, flags:Int32

Parameter	Mode	Type	Default	Description
camera	In	Int32	required	Camera handle.
flags	In	Int32	required	1 = frustum culling (default), 2 = culling of faces on the GPU (default), 4 = with 2, also leave out the faces that look away on the GPU (default off). Other bits are ignored.

Description

Chooses what is left out of the picture of a camera before it is given to the GPU. flags is a set of bits (the default is 3, bits 1 and 2): 1 turns on frustum culling (meshes that are completely outside of what the camera sees are not drawn at all) and is on by default, 2 turns on culling on the GPU, which leaves out the faces of big meshes that are outside of the view and is on by default too, and 4 (together with 2) also leaves out the faces of big meshes that all look away from the camera, which is off by default too. The flags are only an optimization and never change the picture. See Culling for how they work and when they help. This is a BlitzLLVM extension: the originals leave this to Direct3D.

CameraCulling camera, 0 draws everything, which is useful to measure what culling saves. The bits of flags can be used alone: CameraCulling camera, 2 lets the GPU cull but still gives every mesh to it. The setting is used by the camera that CameraCullingSource names for the cameras that take their culling from it.

Examples

Graphics3D 320, 240, 0, 2
SetBuffer BackBuffer()
camera = CreateCamera()
PositionEntity camera, 0, 0, -10
cube = CreateCube()
PositionEntity cube, 100, 0, 0        ; Far outside of the view.
RenderWorld
Print TrisRendered()                  ; 0: not given to the GPU
CameraCulling camera, 0
RenderWorld
Print TrisRendered()                  ; 12: given to the GPU, which finds nothing to draw

Related Commands

CameraClsColor, CameraClsMode, CameraCullingSource, CameraFogColor, CameraFogMode, CameraFogRange, CameraProject, CameraProjMode

Command Index · Blitz3D · Cameras