There are different types of materials you need to be aware of when working with Showcase.
Showcase materials are built specifically for Showcase and have a variety of realistically looking presets. Showcase materials are very customizable, giving you complete artistic control to present them artistically or realistically. Showcase material textures can be placed independently of object UVs and therefore allow for more flexibility. Showcase materials can be mapped using planar, triplanar, and cylindrical projections in addition to parametric UV mapping.
Extended Showcase Materials are based on a selection of Autodesk Material presets, but allow for the same flexibility as Showcase materials. You can find them in \Program Files\Autodesk\Showcase 2012\support\ExtendedMaterials\.
Autodesk materials are common to products such as AutoCAD, Inventor, Revit, 3ds Max, and so on. Showcase supports Autodesk materials imported in models from the preceding products. Autodesk Materials are more restrictive than Showcase materials as they are based on real-world physical parameters and are presented to you that way in their properties. Autodesk material textures only adhere to object UVs for placement. Autodesk materials have the same appearance in Showcase as they had in the originating Autodesk application.
With this information in mind, choose the appropriate type of material for your intended purpose. There may be times where you would like to replace an imported (Autodesk) material with Showcase materials, as described in Replace imported materials. Or you may want to map imported materials to other materials, as described in Define a material replacement mapping algorithm.
