The texture editing tool has two modes to work with, Overview Mode and Edit Mode.
Overview: Only the modified parameters are displayed; the rest are hidden.
Edit: All available parameters for bitmap editing (Texture Properties, Tonemapping, and Coordinates) are displayed.
Any parameters modified here will be displayed in Overview Mode.
By default, the Thea Material editor is in Overview Mode, displaying only the path to the file and any modified parameters. To start editing the bitmap, click the hamburger menu icon and select Edit Mode.
Projection: Press the down arrow, and then select a projection for the selected texture: UV, Cubic, Cylindrical, Spherical, Flat, Front, Shrinkwrap, Camera Map, Cubic (Centered), and Flat (Centered).
UV Channel: You can link a texture to a channel (e.g., Diffuse, Refraction, Bump, etc.).
Channel: Two main channels exist for a texture, the RGB channel and the Alpha channel.
Interpolation: Select a type of interpolation for the selected image: None, Bilinear, or Trilinear.
Repeat: Force the bitmap texture to tile in all directions.
Invert: Invert all the colors of the texture to their complementary colors.
Gamma: Use a value from -100% to 100%. In the next images, you can see how the gamma affects the appearance of the texture.
Red/Green/Blue Shift: You can increase/decrease a texture color value to correct its tone.
Saturation: Use a value from -100% to 100%. In the next textures, you can see how two extreme values for saturation affect the tone of the texture.
Brightness: Use a value from -100% to 100% to control the tone of the texture. A brightness of -100% makes the image completely black.
Contrast: The contrast of the texture.
Clamp Min and Max: Specify the minimum and maximum clamp of the selected texture. RGB colors normally range from 0 to 255. By setting, for example, the minimum clamp to 20%, the colors with RGB values less than around 51 will be “cut” and get this value. By increasing minimum clamp percentage, the image turns whiter, while decreasing the maximum clamp percentage results in darker image colors. By decreasing the maximum percentage and increasing the minimum at the same time, textures tend to appear grayer, as gray colors has RGV values around the middle of the 256 colors (128, 128, 128).
Offset X and Y: Offsets the bitmap over the x- or y-axis.
Spatial Size (X and Y): Spatial size is used to correctly account for scaling when changing from UV to cubic coordinates, while UV scaling affects the scaling once UV projection is used.
UV Scale X and Y: Scales the bitmap over the x- or y-axis.