Models and Texture Maps
Models are made up of polygons where each individual polygon can have one color and one material assigned to it. In a similar fashion, Texture Maps are made up of pixels where each individual pixel can have one color and one material assigned to it.
But what is really being assigned to the polygon or the pixel is just an index number which then references a table with an entry describing the material assigned to it. The render engine looks at each polygon or pixel and, based on the number it finds there, renders the appropriate material from the library onto your screen.
By default, when you create a new model, all its polygons are automatically assigned material index zero. A new texture map will also have material index zero assigned to each of its pixels.
Material Index Zero
Material index zero, named Flat Color, is both unique and a little weird (sometimes difficult to understand).
The Flat Color located at material index zero is the only one that cannot be replaced by a custom material. It will always be Flat Color.
When you pick any other material from the material table, material index zero temporarily ASSUMES the identity of the chosen material, even though the embedded index number for the model polygons or texture map pixels remains zero.
Each time you click on another material, those polygons or pixels embedded with material index zero ASSUME that new material appearance.
In other words, Material Index zero acts like a chameleon and is ALWAYS DYNAMIC OR “LIVE”. (note that two of the buttons on the Embed-Mat menu will cause the model, subtool or the texture map to blink if material index 0 is still assigned to it!)
If you want to permanently assign any other material (above index zero) to a model or texture map you need to EMBED the new material’s index number in the model polygons or texture map pixels.
Normally, to embed a model you first select a material from the table, then press the Draw:M button and finally, press the Fill Object button in the Color Menu.
To embed a texture map by hand is a little more complicated. One quick way is to select Plane3d, convert it to a PolyMesh3d model and display it on canvas in edit mode. Choose the material (you want to embed in the texture map) and embed it in the PolyMesh3d (as explained above). Next, choose the texture map you want to embed so it is displayed on the Plane3d. Click the Draw:M button. And finally, click the Tool>Texture>Col>txr button.
After embedding your model or your texture map with a new material, they will no longer change material appearance when you choose another material.