Our last lecture was on lighting and texturing. Alec went over the basic shaders such as Lambert, Blinn, Phong and the Layered shader.
- A point light is an omni-directional light source (like a lightbulb).
- A spotlight is
like that used on stagea cone of light that is very easy to aim.
- The area light is like a point light but cut in half. It is used to simulate light that comes from a larger area. It is also the only light source able to support the volumetric light fog effect.
- Directional light has no point source (good for something far away like the sun) and is used for illuminating all objects across a scene.
- Ambient light can fill in areas of illumination that would be completely black however a limitation is that it can cancel out the effects of bump mapping (global illumination can be used as a substitute).
- Specular value accounts for the reflected highlights.
- Depth map shadows take less render time than ray trace shadows, allow they don’t take into account the transparency of objects. Use depth map shadows of volumetric light fog.
Three point lighting involves a key light, a back light and a fill light. Your key light is the main light source. The purpose of the backlight is to give the subject a rim light in order to separate it from the background. The fill light (lower than key) is then used to illuminate shaded surfaces to lessen the contrast.
Four point lighting has the same layout but with an additional background light that’s used to illuminate shadows cast by foreground subjects as well as giving depth to the shot.
For my other module, where my team is creating a 30 second creepy animation, we could use the three point lighting technique on our character. By dimming the fill light and creating a bigger contrast, or by removing the key and fill we could create a silhouette, to emphasis that uneasy feeling for our short.
We were given this model to practice our lighting on:
Testing the light fog:
Three point lighting tests:
Creepy lighting tests:
High contrast between light and shadows along with silhouettes and long shadows (due to lowering the light source) can create a chilling atmosphere. One of the best techniques in my opinion is the classic blood-red rim light.
Trying to create a scene where a street light is creating a eerie mood:
Itchy article: http://www.itchy-animation.co.uk/tutorials/light01.htm