SoSlicealphaUse Property |
Specifies how to use the alpha component of each voxel's RGBA value.
Namespace: OIV.VolumeViz.Nodes
. Default is ALPHA_OPAQUE.
Compatibility Note: The default value changed with the release of Open Inventor version 10. In previous versions the default value was ALPHA_BINARY.
The alpha component will typically come from the transfer function, but (since Open Inventor 8.5) could come from direct rendering of an RGBA volume. The alpha values used for rendering the slice will vary depending on the value of this field.
The following table shows how the alpha value is computed according to this field and the incoming voxel alpha values:
When alphaUse field is: | ALPHA_BINARY | ALPHA_OPAQUE | ALPHA_AS_IS |
Incoming Alpha value | Alpha Value Actually Used | ||
= 0 | 0 (Invisible) | 1 (Opaque) | 0 (Invisible) |
> 0 | 1 (Opaque) | 1 (Opaque) | same as incoming |
Note that this field only affects alpha values coming from the transfer function or an RGBA volume. Global transparency assigned by an OIV.Inventor.Nodes.SoMaterial node is not affected.