| The “Scanning Electron Microscope” setting.
| Bump maps under radiosity. |

| What It Does TG Virtual Light is a shader which comes with its own inbuilt light source, which is used to calculate diffuse lighting only. It is best used as a layered shader. Features and Suggested Uses 1. Point or Infinite light sources can be used. 2. Fall-off can be None, Linear, or Squared, and the fall-off distance can be set. 3. Unlit areas can be coloured - in effect, it can act as two opposing light sources. 4. The lighting responds to bump maps. 5. The lighting can “break the laws of physics” - areas which face away from the light source can still receive illumination. The angles at which the illumination reaches its maximum and minimum is user controlled. This makes it easy to simulate hemispheric lighting from one virtual light alone (although without the shadowing associated with hemispheric lighting). 6. You can give any object its own light source, which only illuminates that object. This allows you to easily highlight a particular object, without having to try and set the trueSpace light sources to achieve the effect. 7. Because the virtual light is not a trueSpace light, it is unaffected by radiosity. This allows you to add a “conventional” light into a radiosity scene, and it also means that the bump mapping from the virtual light is retained under radiosity. 8. The light is calculated just as if it existed within a trueSpace scene - so a moving object painted with this shader will act as if it was moving relative to the virtual light. 9. The shader can produce a “scanning electron microscope” effect. 10. The virtual light source can be set to come from the camera position - now you can easily add such lighting to simulate a flash gun fill-in light or similar. Limitations 1. The virtual light does not cast shadows. 2. The illumination from the virtual light does not affect the amount of light “bounced” from an object under radiosity. 3. The shader cannot be layered with any material which uses transmission (and may give unwanted results if the object it is painted on reflects another part of itself). |

| TG Virtual Light Intro |
| TG Virtual Light Parameters |
| TG Virtual Light Tips |
| TG Virtual Light FAQ |
| TG Virtual Light Samples |
| TG Pack Index |