Visual programming interface for a three-dimensional animation system for defining real time shaders using a real-time rendering engine application programming interface

Abstract

A visual programming interface allows an artist to create real time shaders using a tree of shader nodes. Each shader node represents an operation that can be performed in real time through the real time rendering engine. The visual interface allows the arbitrary combinations of these shader nodes to be made and allows the parameters of the shaders to be manipulated or animated. The visual programming interface may be activated in an interactive animation environment through a designation that a real time shader is to be applied to a surface. By integrating the visual programming interface with an interactive animation environment, an artist can experiment readily with different custom real time shaders. An artist also has the flexibility to create arbitrary real time shader trees and to view them interactively without requiring a programmer to develop or modify a custom shader. Basic operations represented by such shader nodes include drawing to a frame buffer (which may include a blending operation with the contents of the frame buffer), a transform operation and lighting operations. A tree of shader nodes may be processed in multiple passes. Each drawing operation in the tree defines a separate pass. The result of each pass is blended with the results of prior passes according to parameters defined for the drawing operation.