Material
Materials and texture paths in the OBJ format will be defined in a separate file (*.mtl). Here you can define if and how materials should be imported. Many times it's important to correctly import the material assignments so they can subsequently be replaced by other/better materials (complex materials cannot be transferred loss-free from one system to another).
The Target option in the general import/export settings defines if an imported material should be transferred to a Standard/Physical renderer material or the higher-end Redsiift Default Material.
Imported materials will be assigned directly via Material tag (UVW projection) an, if necessary, with the help of Polygon Selection tags. This is done in the following ways:
No *.mtl files will be read and no materials will be imported.
One material is created per imported object (the material color can be affected using the Default Material setting described below).
Enable this option if the corresponding *.mtl file should also be loaded. Materials and textures will, for the most part, be imported as they are in the source file.
If no *.mtl file (or object with no materials) is found, the Default Material setting will define the material colors.
Only the material names and polygon assignments in the OBJ file will be imported. Corresponding material properties (color, textures, etc.) will not be imported. The materials created will assume the color defined by the Default Material setting.
If Material is set to One default per object, you can define which color the material should have:
- White: a bright white
- Random Colors: Each imported material will be assigned a random color. With this option it is, for example, easy to determine how the objects are broken down.
When textures are imported, this selection menu defines how the Mix Mode (e.g., in the Color channel) will be set in each material channel. The default setting is Normal.
The purpose for this selection menu: Programs such as Maya set the color in the respective channels to black if textures are used. The OBJ specification also defines the mix mode Multiply. In spite of the texture, both of these combined would be black in Cinema 4D. The Normal setting would make the texture visible.
Enabling this option might help if odd effects occur with regard to transparencies upon import (the material is too transparent or completely transparent when imported). It can occur that an application outputs transparencies inversely or interprets them so. If this option is enabled, the default Transparency channel's Brightness will be inverted (if 90% is defined in the OBJ file, Cinema 4D will define 10%). With this option disabled, 90% will also be defined in the Transparency channel.