CODEWITHSUNDEEP
mathmatrixcoordinatestransformprojection
genesys
genesys

Reputation:

mapping from normalized device coordinates to view space

I'd like to map from normalized device coordinates back to viewspace.

The other way arround works like this:

viewspace -> clip space : multiply the homogeneous coordinates by the projection matrix

clip space -> normalized device coordinates: divide the (x,y,z,w) by w

now in normalized device coordinates all coordinates which were within the view frustum fall into the cube x,y,z € [-1,1] and w=1

Now i'd like to transform some points on the boundary of that cube back into view coordinates. The projection matrix is nonsingular, so I can use the inverse to get from clipsace to viewspace. but i don't know how to get from normalized device space to clipspace, since i don't know how to calculate the 'w' i need to multiply the other coordinates with.

can someone help me with that? thanks!

Upvotes: 0

Views: 4513

Answers (2)

wip
wip

Reputation: 2442

The flow graph on the top, and the formulas described on the following page, might help you : http://www.songho.ca/opengl/gl_transform.html

Upvotes: 0

Andrew Khosravian
Andrew Khosravian

Reputation: 1099

Unless you actually want to recover your clip space values for some reason you don't need to calculate the W. Multiply your NDC point by the inverse of the projection matrix and then divide by W to get back to view space.

Upvotes: 2

Related Questions