GPU PRO 3

86 I Geometry Manipulation

us from entering this “dangerous” state since it is now valid on the API level to

have the same texture bound on both input and output.

An optimization for GPAA is to prefilter the mesh geometry and only draw

lines for edges that are deemed necessary to antialias. For instance, shared edges

between coplanar polygons can be excluded. It is also possible to store the poly-

gon normals for each edge and only draw silhouette edges, i.e., where one normal

points towards the camera and one points away. Using a geometry shader and

adjacency, it is also possible to accomplish the same. In this case no additional

memory is required