Yet another blog about WPF, Surface, SL, MVVM, NUI....

Introduction

When you defines a material in Ogre or in 3D engines in general, you can play with at least four differents parameters : Ambient color, diffuse color, emissive color and specular color.

In this post I will give you the definitions and show you some example for those who - like me - requires some visual example to understand better...

Definitions

Here are the definitions (found on the web...) :

Ambient color : Ambient color is the color of an object where it is in shadow. This color is what the object reflects when illuminated by ambient light rather than direct light.

Diffuse color :Diffuse color is the most instinctive meaning of the color of an object. It is that essential color that the object reveals under pure white light. It is perceived as the color of the object itself rather than a reflection of the light.

Emissive color : This is the self-illumination color an object has.

Specular color :Specular color is the color of the light of a specular reflection (specular reflection is the type of reflection that is characteristic of light reflected from a shiny surface).

All object material can so define these 4 parameters. The color will then depend on them but also of the light they receive.

Examples

All the example are done with a point light, placed at the position (350, 400, 800);
With this type of light you define two colors, the ambient one and the diffuse one.

First example

The light parameters are :

• Ambient color : White
• Difusse color : White

Second example

The light parameters are :

• Ambient color : Red
• Difusse color : White

Third example

The light parameters are :

• Ambient color : Red
• Difusse color : Red

Conclusion

As a conclusion : nothing is better than experimentation !