In fact, for any triangle, graphics cards are specially designed so as to be able to do this interpolation the normals from the three vertices at each corner, very fast. If, instead of looking at face normals (the direction the face is pointing), the renderer looks at vertex normals (the direction the corner is pointing) then it can interpolate (a kind of averaging) this direction across the triangular face it is rendering, giving it something of a smooth look. This second option is often what we want, and this is where vertex normals are used. Either it can render each polygon (or face) of this shape as a flat surface and do lighting calculations based of that, or it can try to render some smoothed version of the same shape.

When a computer renders a shape on the screen there are two options. They can be thought of as the corners of geometric shapes. The main two examples of this being the default method by which vertex normals are calculated and the way in which Catmull–Clark subdivision (after which the technique is named) works.Ī vertex is a point in space where various lines (or edges) meet. The technique and subsequent art of subdivision modelling arose more or less naturally due to several aspects or phenomena in how digital art is typically rendered. Other popular techniques are per-poly modelling, nurbs modelling and digital sculpting. Saying this, it is often at the discretion of the artist or the tool, as to what modelling technique they choose to use. It is used to some degree in almost all industries that employ digital artists. Subdivision modelling is a technique of digital 3d modelling used to create clean models with scalable detail that look good when rendered. Subdivision Modelling Created on March 31, 2011, 3:17 p.m.

Sub d modeling rhino