Forum

Warping the Renderer output so you can project on a wall and skew it?

Hi there, how would I go about this?

I’m using a projector and it’s not directed straight at the wall but more at a 40 degrees angle to it.

My projector only has options to adjust the vertical skewing but not the horizontal skew.

Is this something that vvvv could handle in realtime? Ie outputting a video file and giving me the options to adjust the skewing while it’s playing until I get it to look unskewed?

The transform3D gives me some control when plugged into the “View Transform” Pin of my “Renderer” Node, but I can’t get it to “skew” as in scale one side smaller while other is larger, if that makes sense?

basicly you can try with 3d rotate, just imagine you need to orient the quad as you looking from projector point. Homography node is used for that

huh. have a look at Homography (Transform 2d)

Perfect, thanks guys! Problem solved.

@antokhio and @others:
Is Homography (Transform 2d) like a rotation? Or like a distortion?

I’m a bit confused about View and Projection Pins on Renderer (EX9)

Where to apply the homography when using a Camera (Transform Softimage)?

Now I’m achienving this thanks to * (Transform) but maybe also the Distorsion on Camera node can work as well…

…Could anyone point me in the right direction?

Keystone and Camera (9.3 kB)

Make a homography node, highlight it and press F1 to get the help patch. That will show you how to connect it to the renderer.

@sune
I know very well the help patch of homography, I always copy and paste from there. I made also a Keystone for myself…

In the help patch the pin used on the rendered is the Projection

…I was asking:
When there’s a Camera involved that needs a _View _and a _Projection _, Where to link the homography?