These three example show how SketchUp handles transparent materials. At 70% opacity and above, SketchUp blocks the light. Below 70% opacity, SketchUp allows 100% of the llight to pass through.
Wall with open hole - no transparency or translucency.
(The image of the window, around the shadow of Sang is fully illuminated.)
Wall with 50% transparent hole - allows 100% of light to come through.
(The image of the window, around the shadow of Sang is still fully illuminated.)
Wall with 25% transparent hole - (75% opacity) - no light comes through.
(SketchUp does not process partial shadow effects through transparent glass.)
Translucent examples allow light to pass through, but block part of the visibility. (In SketchUp this can be performed with a single face with a material set to 90% or 100% opacity, but with shadows disabled. There is no way in SketchUp to get partial shadows.)
This is a translucent effect. we cannot see through the window, but light passes through the window.
We can see Sang through the window, but Sang does not cast a shadow on the translucent window itself.
Ray Trace Examples
A Ray Trace
Renderer will cast partial shadows based on transparency. Here is a sample of the 50% transparency run through a Ray Trace Renderer (IRender nXt
50% transparency with Ray Trace - note some light is blocked and we get a partial (blue) shadow.
Ray Trace Translucency
90* translucent window - very little can be seen through the window, but light passes through it.
We can also see Sang - just slightly - and Sang casts a shadow on the window as well as the ground.
A better example of translucency is with lamp shades.
The shade on the left is 90% translucent - we can wee the light bulb vaguely.
The shade on the right is 100% translucent - we cannot see the light bulb.
However, light from the light bulbs illuminates the walls throught the translucent shades.
Render Plus March 31, 2007