Creating Real Time Shadows 

This task shows you how to create real time ground shadows to simulate in a very realistic way the reflections of an object on its environment walls.
Open the Lamp.CATProduct document.
  1. Create a directional light source by clicking Create Directional Light .

    Only directional light sources can cast real time ground shadows.
  2. Create an environment (you can also apply textures on the walls). The model should look something like this:

    In case no environment exists, a default environment (very big and with transparent walls) is created.
  3. In the specification tree, select the Bottom wall and display its lighting properties by right-clicking then selecting Properties.

  4. Click the Lighting tab and make sure that the On check box is selected.

  5. Access the lighting properties dialog box (by selecting the light in the specification tree then Properties or Light object > Definition), click the Shadows tab then select the On Environment check box:

  1. Set the following parameters using the corresponding slider or enter directly a value in the corresponding box:

    • Smoothing: defines the shadow attenuation, i.e. the limit between light and shadow. The higher the value, the more attenuated the limit. For instance, "0" means a clear break with no attenuation
      at all

    • Color: lets you define the color of the shadow by clicking the button to select the desired
      color. The slider sets the color intensity

    • Transparency: sets the opacity of the shadow. The higher the value, the less opaque the shadow.

  2. Click OK to validate when satisfied with your parameters.

    The shadow of the lamp now appears on the bottom wall as shown below:
    You can move the created shadow simply by dragging and dropping the compass onto it.


Macros are provided to automate the activation/deactivation of real time shadows. Refer to the "Use Cases" section in the Real Time Rendering Automation documentation for detailed information.