This section describes the parameters situated on the gradients page that are used by all colours textures. In addition this section describes colour maps and how they relate to RJJ textures. To go directly to a particular section click on the links above. "BACK" will take you back to the contents page.

A colour map defines a set of colours, alpha values and blend points that allow colour to be applied to an object based on a prefined function (i.e. the texture). The easiest way to understand a texture in the case of all RJJ textures is to think of each pattern being a function that returns a value between 0.0 to 1.0. In the case of rjlinear this value increases linearly along the axis selected for the pattern whereas in the case of rjbozo its a random value. This value is then used as the basis of the colour maps (or in fact the bumps in bump textures). With a single colour texture, four blend points and four colours map directly to this value. The same relationship is true for the alpha values and blend points. The mechanics of this mapping are described below.

For each texture four colour values are allowed, these are colour1 to colour4. colour1 relates directly to blend1, color2 to blend2 and so on. To understand how the alpha value are mapped to the textures refer to the section on Blend Values.

For each texture four alpha values are allowed, these are alpha1 to alpha4. alpha1 relates directly to blend1, alpha2 to blend2 and so on. The alpha values provide an extra channel for controlling the reflectivity, transparancy and layering of the textures independantly of the colours. These are discussed below:

Alpha Filter When the affect filter option is enabled and the alpha channel has been selected the alpha values will be used to control the objects transparency based on the texture's function. This means that the object will be totally transparent where the alpha values are 255 and totally opaque where the alpha vales are 0. Values in between will affect the transparency proportionally.

Alpha Reflect When the affect reflect option is enabled and the alpha channel has been selected the alpha values will be used to control the objects relectivity based on the texture's function. This means that the object will be totally reflective where the alpha values are 255 and non-reflective where the alpha vales are 0. Values in between will affect the reflectivity proportionally.

Alpha Layer The most important use of the alpha values is for layering tetxures. When the affect layer option is enabled the alpha values are used to determine how much the colour is blended with any underlying textures or colours. When the alpha value set to 255 no colour will be applied and the underlying colour/pattern will shown through. If the alpha value is set it 0 then the texture is applied full on. Values in between will affect the layer proportionally so that layers are blended together. In this way a texture can be applied with bits showing through or partially obscured.

A simple example of this is shown below. The first figure shows a simple with a vertical red/green stripe applied, The second figure shows a the same plane with a second horizontal yellow/blue stripe applied. The final figure shows the same object with the alpha value set to 255 where the the colour was yellow on the horizontal stripes. Here, it can be seen the the underlying stripes show through. More examples of the layering can be found in the controls page section under affect layer.

To understand how the alpha value are mapped to the textures refer to the section on Blend Values.

The blend values control when the colour and alpha values are applied and blended based on the tetxure's function. These blend points are based directly on the texture's function value of 0.0 to 1.0 which is why they have a maximum value of 1.0. On a single colour texture the blending works in the following manner: Colour1 is applied until blend1 is reached. Colour1 is then blended to colour2 between blend points 1 and 2 such that colour2 is applied "full on" at blend2. Colour2 is blended to colour3 between blend points 2 and 3 so that colour3 is apllied "full on" at blend point3. Finally, colour3 is blended to colour4 between blend points 3 and 4 so that colour4 is applied "full" on at blend4. The figures below show examples of different blending. Here a rjlinear is applied across a simple plane. Colour1 is red, colour2 is green, colour3 is blue and colour4 is white. Notice how the blending occurs for the different examples.The same blending occurs for the alpha paramters.

With blending switched off the blend point operate is a different manner. In this case colour1 is applied up until blend1. Colour2 is applied between blend1 and blend2. Colour3 is applied between blend2 and blend3. Colour4 is applied from blend3 onwards. The same blending examples shown above are used but this time the blending is switched off.The same blending occurs for the alpha paramters.

Finally, when large colour maps are being created by stacking textures, there is one extra blend to bear in mind. This is the blend between two textures when the second texture has its use last layer option enabled. Here, a blend occurs between colour4 of the first texture and colour1 of the second texture. This is achieved between blend4 of the first texture and blend1 of the second texture. If blending is switched off then colour4 of first texture is applied until blend4. Colour1 of the second texture is then applied between blend4 of the first texture and blend1 of the second texture. The same blending occurs for the alpha paramters.