Lesson plan
Sphere mapping
In computer graphics, sphere mapping (or spherical environment mapping) is a parameterization of directional radiance obtained by projecting the reflection of a mirrored sphere onto a plane using an orthographic projection. The resulting 2D texture encodes incident light as a function of direction and is used for reflection mapping by converting a surface reflection vector into texture coordinates. The method assumes the environment is distant (so radiance depends only on direction), but it introduces non-uniform distortion and contains a singularity in the direction opposite the viewing direction used to create the map. To use this data, the surface normal of the object, view direction from the object to the camera, and/or reflected direction from the object to the environment is used to calculate a texture coordinate to look up in the aforementioned texture map. The result appears like the environment is reflected in the surface of the object that is being rendered.
Article summary
In computer graphics, sphere mapping (or spherical environment mapping) is a parameterization of directional radiance obtained by projecting the reflection of a mirrored sphere onto a plane using an orthographic projection. The resulting 2D texture encodes incident light as a function of direction and is used for reflection mapping by converting a surface reflection vector into texture coordinates. The method assumes the environment is distant (so radiance depends only on direction), but it introduces non-uniform distortion and contains a singularity in the direction opposite the viewing direction used to create the map. To use this data, the surface normal of the object, view direction from the object to the camera, and/or reflected direction from the object to the environment is used to calculate a texture coordinate to look up in the aforementioned texture map. The result appears like the environment is reflected in the surface of the object that is being rendered.
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
No sources recorded.
Key claims and bibliography are generated from the same tracked claims and sources as the article page.