Two Types of Dummy for GI

The dummy props are now can be assign to two different types for using in the GI environment for specific purposes: to emit lights or to block lights.

Keep GI - Hiding Emissive Prop with GI Effect

Usage

  • Keep the GI effect from an emissive prop (Glow or Self Illumination) without rendering the prop itself.
  • Can be included in the scene as auxiliary lights.
  • Can be used as the main source light.
    Please click Here to view the comparison.
  • Suitable for Final Render quality.

Instruction:

  1. Under Modify > Material > GI Settings, enable Illumination.
  2. Adjust Glow / Self-Illumination Scale and Self Illumination to ideal values.
  3. Under the Modify > Edit > Prop, enable Set as Dummy.
  4. Select Emit GI in the drop-down list.
  5. Show or hide the dummy object by pressing Ctrl+D.

Block GI - Blocking Lights for Fixing Leaky GI

Usage:

Previously mentioned GI Known Issue about light leakage with thin walls can be fixed by wrapping the walls with a thick encasing.

However, this solution is rather unsightly. With Block GI you set the encasing prop as a dummy object and hide it.

ClosedNote:

You can show or hide the dummy object by pressing Ctrl+D.

The original blocking panels as shown below

Under Modify > Prop, enable Set as Dummy and select Blocking GI in the drop-down list as shown below:

ClosedNote:

Please note that the light leaking issue can only be fixed for Directional Lights and Spotlights. There is currently no resolution for other lights sources such as Point Lights and Emissive Objects.

Mechanism

In the following illustration, the left one is when the directional light is occluded by a blocking dummy then the GI emitted by the red block is weakened; while the right one is when the blocking dummy is behind the red block then the full force of the directional light is exposed on the red block creating very strong bounce lighting.

ClosedNote:

Blocking dummies work best when they are closer to the occluded object.

The following illustrations demonstrate the importance of light exposure sequence. You can see an encasing blocking board that is set to a Blocking GI dummy and a directional light that pointing towards the bottom left.

Since the green wall on the right is occluded by the blocking dummy, it does not emit any bounce lighting. On the flip side, since the red wall is being hit directly by the directional light, it does emit bounce lighting even though behind it resides the encasing blocking dummy.