Alpha

Alpha

This node controls the transparency of rendered objects.

The Alpha node controls the transparency of all subsequent objects in the Scene Hierarchy. To achieve correct transparency effects the right drawing order must be respected. Transparent objects must be rendered after those objects which lie behind them. For more information, see Introducion to Realtime Rendering.

The Alpha node provides the following Input Properties:

The AlphaValue controls the amount of opacity. 100% results in a completely opaque object.
AlphaRelation specifies how the resulting alpha value is calculated if more than one Alpha node affect an object. In Relative mode the Alpha values are multiplied. In Absolute mode the last Alpha node specifies the transparency. All former nodes have no effect anymore.
If the AlphaBlock property is enabled and AlphaValue is set to 0% the subsequent tree is blocked and thus neither validated nor rendered. This is a performance optimization.

The nodes Color and Material also have the Alpha properties available.