The Col tab contains color and other surface property related settings. These controls provide a simple and easy way to modify surface appearance (shading) of objects. When more control is needed, VSL materials provide a more powerful way to define shading properties.
Surface attributes defined in the Col tab are evaluated before the materials assigned to the object. This has two consequences:
Attribute: This gadget contains a list of ordinary surface attributes. Color is the most commonly needed attribute, but you can also define Illumination (=self illuminating color), Reflection, Transparency, Fade, Alpha etc. properties here. For more information about channels, check the Channels documentation.
Clear: Removes the value for the attribute defined by the previous field from the object. The object will then use a value possibly defined by a parent level, or if the parent value is not set, the default value of the attribute.
Attribute Value: This field controls the value of the selected attribute. A floating point, vector or color gadget is displayed depending on the attribute type.
Method: Selects the type of the texture mapping. A color map defines the usual diffuse color. 'Environment map' makes the object mirror like (black diffuse color, full reflectivity) and uses the defined texture file as a spherical reflection map for the surrounding world.
Texture: The name of the image file for texturing.
Translate, Scale, Rotate, Skew: These four gadgets define a texture transformation matrix. For example, the texture can be tiled and repeated several times by decreasing the two first components of the Scale vector.
Render Caustics: Enables caustics rendering for the object i.e. makes the object receive caustics illumination. Note: the top level caustics switch in the render settings must be also enabled.
Width, Height: The accuracy of the caustics effect for this object. Caustics illumination is stored to a object specific illumination map, and these values define the resolution of the map. The higher the resolution, the finer details caustics illumination contains. However, high resolution usually requires that the caustics Sampling value is high enough - otherwise the illumination details may become too weak or noisy. A good thumb rule is that Width and Height are about the sampling value multiplied by ten. For example, the default sampling rate 20 is enough for a 200*200 caustics map.