Surface inspection planning systems should take in the account geometry and material properties of the inspected object in order to guarantee complete surface coverage. Modeling and rendering realistic material still represents an open question. The appearance of the object depends on numerous parameters and it can significantly influence the visibility of the surface from a certain viewpoint. Therefore, realistic appearance modeling and rendering are crucial for the planning process. To achieve the realistic appearance of the surface, it is important to utilize models developed in the field of optics and combine them with physically based material modeling in the field of computer graphics.
Our goal is to explore existing and create new material models for the realistic appearance of the rendered images. Realistic appearance is a result of complex light-matter interaction. Appearance modeling in computer graphics is aiming to reproduce this complex phenomenon which is traditionally divided into light scattering models and texture. Light scattering models take in the account the amount and the direction of the incoming light, as well as viewing direction with respect to the surface normal. These models result in smooth surfaces. On the other hand, the texture is used to introduce a variation of material parameters over the surface (i.e. color or normal). We are interested in modeling surfaces that exhibit spatial variation on a wide range of scales and patterns. We believe that this goal can be achieved using parametric (i.e. procedural) material models.