Perspective Correct Mapping

Hi,

Is there an option somewhere to enable perspective correct mapping?
http://en.wikipedia.org/wiki/File:Perspective_correct_texture_mapping.jpg

I use [sites/default/files/user-files/GridDeform.v4p](https://vvvv.org/documentation/sites/default/files/user-files/GridDeform.v4p) to modify a mesh, but I get distortions on my mapping.

Thanks

Homography

Thanks io, but I’m not talking about projection mapping.
Check the wikipedia link. It’s about 3d rendering and how to display texture in perspective.
Try GridDeform with a texture applied on the mesh. As soon as you move a vertex, texture is deform, but you can really feel triangle distortions.
Perspective correct mapping is an old feature that appeared back in the first days of realtime 3d rendering (remember 3dfx graphic accelerators ;-) ?)

Thanks

Hi there… what is GridDeform?

BTW here I need some info:
seems that homography is the answer for simple problem:

but it’s not working for more than one quads… so I can use GRID with some high X and Y resolution:

but when it come to join 2 grid, in order to make a cubic shape, there is a problem with joining the texture on the corner (look the green line)
how can I make it look better?

HomoQuadGrid.rar (29.6 kB)

Hi
what I d do is to use real 3D objects with the proper perspective corrected by the camera.

real3d.zip (34.6 kB)

Ren0,

Unfortunately, I’m still struggling with this stuff myself, but I also don’t understand what you mean by gridDerform…

Luper,

and this might be an idiotic answer, but wouldn’t the texture align itself if you used it like this while adjusting it on an actual ‘cubic’ shape, not a skewed one? Like so: see patch

Homo_GridNew.v4p (18.8 kB)

You are right purf. it can get correct if you adjust all four corners precisely. so having the actual corners to adjust after helps a lot. I have tried from time to time adjust with no fixed point, then it can take quite a while to get the adjustment completely right.