Textures are image maps you can use to vary shader parameters across a shaded surface. For example, you could photograph the surface of a rock, then that image as a texture on the Color parameter of a material to make the material look up the colors from the rocky image as it shades, making the 3D object take on the texture of the rock.

Using textures usually requires first assigning UV coordinates to the geometry you want to shade.

UV coordinates map positions on a polygonal surface to corresponding positions in a texture map. In Houdini, UV coordinates are stored in a uv attribute. For example, a point in polygon mesh might have a uv attribute of (0.5, 0.5), meaning that point corresponds to a position in the center of the texture map (which has coordinates ranging from 0 - 1).

• If you are using an “über-shader” such as the Principled shader, it will usually have controls to let you use a texture for a certain parameter.

• If you are building your own shader, you can use a shader effect to quickly add a Texture VOP to an input.