An Alpha Image is a raster image which has an Alpha Channel to define transparency.
When an alpha images is loaded into SketchUp, or used as the texture for a material, the parts of the image which are transparent are also ttransparent in SketchUp, and are rendered properly as transparent in IRender .
The image on the right is an raster image of a speaker with arcs to represent the sound.
The second image show two versions of this raster image imported into SketchUp. The first version is imported normally, and the white in the image appears as white in SketchUp. The second version was imported from an alpha channel image where the white was declared to be transparent. Notice that in the second image, the area that was white is now transparent when loaded into SketchUp.
IRender Alpha Images
IRender can save its renderings as alpha channel images with the background transparent. This lets you easily place the image over a background.
- See: IRender Alpha Images