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paroj / gltut

Learning Modern 3D Graphics Programming
https://paroj.github.io/gltut/
MIT License
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Confused with Tutorial 4, Perspective Projection #70

Open paroj opened 11 years ago

paroj commented 11 years ago

Originally reported by: Anonymous

Which is at (0, 0, 0) in camera space - the camera, or the center of the projection plane?

The tutorial says that "the location of the center of the perspective plane is fixed at (0, 0, -1) in camera space. Therefore, since the projection plane is pointing down the -Z axis, eye's location relative to the plane of projection is (0, 0, -1)." If the eye is pointing down the -Z axis and the eye is at (0, 0, 0), then shouldn't the eye's location relative to the projection plane be (0, 0, 1)?

Later, the tutorial says "The eye is fixed at (0, 0, -1)." What's the right position?

jicksaw commented 5 years ago

I'm also confused about this. In Figure 4.6, if Ē is (0, 0, 0) wouldn't Ez instead be Rz (-1). That is, z-component of R̄.