An Introduction To 3D with Lyndon Daniels

Part 6: Texturing and Shading

Texturing

iThe process of texturing a model is partially done within your 3D Software but often the bulk of your texturing work will require 2D photo manipulation software such as the GIMP or Photoshop.

We already have a shader assigned to our head model which we created during our UV texturing session. We are simply going to modify our Shader to create an additional channel often refered to as a bump or normal map which will make our surface seem uneven, bumpy and more organic-looking when rendered.

We're going to start off by creating a UV snapshot of our head model and taking that snap shot into our photo-manipulation software to paint over it. A UV snapshot, as the name implies, is simply an image exported from your 3D software representing 0 to 1 texture space. Which, at this stage, should contain your characters UV shells layed out.

Texture Creation Guidelines

There is no given methodology for creating a successful texture map, each one is unique and should be addressed as such.
There are however several guidelines that can apply generically across the process of creating texture maps within photo-manipulation software.
  • Setting the resolution of your texture map can generally be as simple as using a 75dpi image, however there are some use cases where a higher resolution texture map might be required for output on a high pixel density screen.
  • Although it is possible to use layered image files as texture maps (such as PSD or XCF files). Rendering times could be imporoved when using flat images such as PNG, TGA or TIFF.
  • If you need to change the canvas size of your bitmap texture after exporting a UV snapshot make sure that you maintain the same aspect ratio (of your original image) in your resized version to avoid UV islands not lining up and therefore creating seams.
  • Avoid moving your UV snapshot around in your photo-manipulation software, as this could result in texture seams showing through on your rendered 3D model.