Materials

After the 3D model has been finished, normally you start applying materials and textures. These will give to the model the "skin" with the paintschemes, and create the differences between parts like transparent canopies, carbon fiber parts, glass fiber parts, wood parts, plastic and so on. Depending on the 3D software used, this part of a project could be one of the most important parts since:

"..a good model and bad materials or textures makes a BAD rendering but a poor model with good textures makes a GREAT rendering."

This means that a lot of research and development of the materials has to be made for not ruining the whole rendering process. Many photos of the real Aircraft (if already built) are necessary, like knowing exactly of what materials each component is made of and possibily having some test samples.