The class allows you to specify the transparency algorithm to use for all subsequent shapes. Transparency handling can be completely disabled by setting NO_TRANSPARENCY.

You can also specify the transparency algorithm globally using SoGLRenderAction or the viewer clases (e.g. SoWinRenderArea).

However, there are some differences in behavior depending on which class you use to set the transparency type.

• Setting transparency type SORTED_PIXELS_BLEND in an SoTransparencyType node is equivalent to setting transparency type SCREEN_DOOR. This transparency type is only effective when set in the SoGLRenderAction or viewer.

• When transparency type SORTED_PIXELS_BLEND or DELAYED_SORTED_PIXELS_BLEND is set in the SoGLRenderAction or viewer, you must be careful using SoTransparencyType nodes in the scene graph. Objects that are assigned to a DELAYED_ or SORTED_ transparency type by an SoTransparencyType node will not be taken into account in the SORTED_PIXELS_BLEND or DELAYED_SORTED_PIXELS_BLEND processing (they will be rendered after this processing).

See SoGLRenderAction for a detailed description of when different shapes, including transparent shapes, are rendered during scene graph traversal.

NOTES:

• Depth buffer. When using a delayed transparency mode, e.g. DELAYED_SORTED_PIXELS_BLEND, the depth buffer is not updated (depth buffer writes are disabled) while rendering transparent objects. As a result complex 3D shapes may not be rendered correctly.

• Traversal order. Delayed transparency modes implicitly modify the order of the scene graph traversal by rendering transparent objects after all opaque ones. As a result, using a specific node to achieve an effect that relies on the order of rendering (for example SoDepthBuffer) may lead to incorrect results.

• Compact paths optimization. When using a delayed transparency mode, paths to transparent objects are saved in a list. After all opaque objects have been rendered, this list is rendered. In order to avoid unnecessary rendering, the common part of each path is rendered only once. This can increase performance on very complex scene graphs. However, in some cases, it can lead to incorrect rendering. In the figure below, node B is a transparent object and node A has a side effect on node B (clipping, shader...). When the compact path optimization is on (the default), node A will not be traversed during the transparency pass, which will lead to incorrect rendering. When a case like this occurs in your scene graph, set the environment variable OIV_USE_COMPACT_PATHS to false to disable this optimization.

  

This class is not available in Open Inventor version 10 and later. Starting with Open version 10, transparency type can only be specified as a property of the whole scene. See the setTransparencyType() method in SoGLRenderAction or the viewer class.

FILE FORMAT/DEFAULT

TransparencyType {

type	SCREEN_DOOR

}

ACTION BEHAVIOR

Sets: SoTransparencyTypeElement

Reference