Shadows

With the standard rendering options (that is, without a radiosity or particle tracing solution present in memory), shadows can be generated with Phong and Ray Trace rendered images only. When a radiosity or particle traced solution is used, you can use Smooth or Ray Trace to produce an image with shadows.

Ray tracing produces the most accurate shadows. With Phong rendering, shadow maps are generated. These approximate the shadows cast by objects in the model.

Normally, constructions should be turned off for a view when it is rendered. Doing this, ensures that any light source cells, for example, do not cast unwanted shadows.

Shadows and Phong shading

In Phong shading, shadows can be generated only for Solar, Distant, Spot and Area light sources.

For shadows to be generated by an object in the model, the Shadows setting must be on for the material definition (if any), the light source, and in the Rendering View Attributes dialog box.

Shadow maps are calculated the first time a view is shaded. Since they are valid for any view, they are not recalculated unless there is a change to the lighting.

If you change the geometry of the scene, you should clear any existing shadow maps so that the shadows are recalculated to include the changes. You can do this by keying in LIGHT CLEAR, or by selecting Clear Shadow Maps from the Mode option menu in the Define Light tool dialog box.

Shadows and Ray Tracing

In a ray traced image, shadows can be generated by Solar, Distant, Point, Spot and Area light sources.

For shadows to be generated by an object in the model, the Shadows setting must be on for the material definition (if any), the light source, and in the Ray Tracing dialog box.

Point, distant, spot, and area lights are actually the light cells PNTLT, DISTLT, SPOTLT and AREALT, respectively, from the supplied lighting cell library "lighting.cel". You can adjust the various settings for these light sources by editing enter data fields in the lighting cells, but it is much easier to use the Define Light tool.