Transforming point position to NDC

[phong]

Hi!

I searched through the expression functions, but couldn't find anything to transform a point from one coordinate system to another. In particular I want to transform a point from world coordinates to NDC. Is there an expression or do I have to go through the matrix stack?

Thanks,

Phong

[SpencerL]

if its at render time, there is a toNDC VOP which does this. If you want to do it at the SOP level, you could use your camera to project the uvs via uv texture SOP, then use a point SOP and in position replace $TX, $TY, $TZ with $MAPU, $MAPV, $MAPW.

[phong]

I want to use it at the POP level would be too cool if there was a uvproject SOP..

[symek]

I want to use it at the POP level would be too cool if there was a uvproject SOP..

Don't have to use projection in pops. In both Sops and Pops land you can use toNDC() with additional parameter for camera name:

$ndcP = toNDC("/obj/cam1", P);

You can paste it to inlineVOP to check how it works.

hth.

skk.

Edited February 26, 2010 by SYmek

[SpencerL]

Don't have to use projection in pops. In both Sops and Pops land you can use toNDC() with additional parameter for camera name:

$ndcP = toNDC("/obj/cam1", P);

You can paste it to inlineVOP to check how it works.

hth.

skk.

Didnt know about that one, Thanks SYmek!

[phong]

Wow how cool. Thanks SYmek