Projective texture mapping: Difference between revisions

Revision as of 20:21, 10 November 2022

Revision as of 03:20, 3 September 2024

Line 6:

== Fixed function pipeline approach ==

Historically{{ref|nvsdk_ptm}}, using projective texture mapping involved considering a special form of eye linear texture coordinate generation{{ref|glEyeLinear}} transform (''tcGen'' for short). This transform was then multiplied by another matrix representing the projector's properties which were stored in texture coordinate transform matrix{{ref|glTCXform}}. The resulting concatenatedconcentrated matrix was basically a function of both projector properties and vertex eye positions.

The key points of this approach are that eye linear tcGen is a function of vertex eye coordinates, which is a result of both eye properties and object space vertex coordinates (more specifically, the object space vertex position is transformed by the model-view-projection matrix).

Because of that, the corresponding texture matrix can be used to "shift" the eye properties so the concatenatedconcentrated result is the same as using an eye linear tcGen from a point of view which can be different from the observer.

== Programmable pipeline approach ==