Lighting and Shadows

There are 3 light types, Point, Spot Light and Directional.  Lighting and shadows are added using the Light Properties dialog

Window: Light Effects menu command activates the dialog. 

Note: Atten = 1 / ( atten1 + atten2 * distance + atten3 * distance2),  Light at location = ColorRGB(N . Ldir) * Intensity * Atten.

Note: A frame is limited to a total of 31 point/spot lights and 1 directional light.

Point Light

Point lights are radial and omnidirectional.  To setup a point light in the scene select an object as Solid A, the object center is used as the point light's location.  Configure the light prosperities and use Apply Point Light button from dialog.

Note: A frame can have a maximum of 8 point lights with shadows.

Example Point Light using half sphere object shown


Spot Light

Spot lights are directional with an umbra/penumbra angle ranging from 1°-89°.  Penumbra is outer region of the umbra which typically is configured to fade or fall off between penumbra and umbra regions.  Penumbra is ≥ umbra angle.  To setup a spot light select a surface from the scene as Surface A, the surface center is used as spot light's location and normal vector is spot light's direction.  Configure the light prosperities and use Apply Spot Light button from dialog.

Note: A frame can have a maximum of 8 spot lights with shadows.

Example Spot Light using surface shown

Note: When shadows are enabled Spot Light is limited to 75° umbra/penumbra

Directional Light

A directional light has no location, uses a fixed 90° umbra and does not attenuate with distance.  Only attribute is direction which is used as parallel light direction for entire scene.  It is best fit to model outdoor sunlight.  The sun can be though of as a point light but it is so far away that on earth it acts like a parallel light source.  To setup a directional light select a surface from the scene as Surface A, the surface's normal vector is used as direction.  Configure the light prosperities and check Directional Light option and use Apply Directional Light button from dialog.

Note: There can only be 1 directional light active in scene.  When shadows are enabled all geometry must be in front of the directional light plane.
Note: Object representing Directional light can be placed in non-visible areas

 
Example directional light using surface shown