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SoGLRenderActionSetSortedLayersNumPasses Method

Sets the number of rendering passes used when transparency type is OIV.Inventor.Actions.SoGLRenderAction.TransparencyTypes.SORTED_PIXEL.

Namespace: OIV.Inventor.Actions
Assembly: OIV.Inventor (in OIV.Inventor.dll) Version: 2023.1.3.0 (2023.1.3)
Syntax
public void SetSortedLayersNumPasses(
	int num
)

Parameters

num
Type: SystemInt32
Remarks

Default is 4.

Note: Since Open Inventor 9.4, if the hardware supports the necessary OpenGL features, these transparency modes are implemented using a single-pass, order-independent fragment sorting (A-buffer) algorithm. Therefore the value of this field is not used except in two special cases:

  • If hardware support for single pass transparency is not available, then the previous "depth peeling" algorithm is used (which normally requires multiple passes), or

  • If volume rendering (see OIV.VolumeViz.Nodes.SoVolumeRender) is combined with geometry rendering, then multiple layers of transparency information are required and this field specifies the number of layers.

Use more passes for more correct transparency. Usually four passes (which is the default value) gives good results. For example, the number of passes needed for rendering an opaque sphere behind two cubes is the number of planes separating the sphere from the viewer. So, when backface culling is enabled, 2 faces separate the sphere from the viewer: the front face of the first cube and the front face of the second cube. The number of passes needed in this case is 2.

The default value for this field can be set using the environment variable OIV_NUM_SORTED_LAYERS_PASSES.

See Also