Light, ShadowΒΆ

Remove an object from the lighting

The Light set corresponds to the set of objects direclty illuminated by a light.

Let's remove the sphere from the area light.

  1. Double-click into the previous NewRenderGraph.
  2. Create a Set node, a binop.remove node and connect them as in the graph below.
  3. Select the new Set node and select 'Lights' in the Set combo checkbox.
  4. Render the image.

The sphere is no more directly lit by the area light. The only remained shading comes from the diffusions (the indirect lighting) and glossy reflections.

This RenderGraph can be explained like this :

In the lower branch that selects the sphere Primitive via the sphere Tag there is a Set node, which associate the sphere in the 'Lights' set, then the binop.remove node removes the sphere from the 'Lights' set, associated in the upper branch, and hence from the lighting of the AreaLight of the scene, since the AreaLight has 'Lights' in its Light Set combo checkbox.

Remove an object from a shadow

The Shadow set corresponds to the set of objects casting shadows in a light.

Let's remove the shadow cast by the sphere with respect to the area light.

  1. Double-click into the previous NewRenderGraph.
  2. Create a Set node, a binop.remove node and connect them as in the graph below.
  3. Select the new Set node and select 'Shadows' in the Set combo checkbox.
  4. Render the image.

The sphere do not more cast shadows.

This RenderGraph can be explained like this :

In the lower branch that selects the sphere Primitive via the sphere Tag there is a Set node, which associate the sphere in the 'Shadows' set, then the binop.remove node removes the sphere from the 'Shadows' set, associated in the upper branch, and hence prevent it to cast shadow with respect to the AreaLight of the scene, since the AreaLight has 'Shadows' in its Shadow Set combo checkbox.