Projecting onto a curved surface

Ive just had a quick look around but still cant figure which nodes to use and how to create a patch to project on to a curved surface. All i am looking for is to experiment using one beamer to project on to a concave screen. Can anybody point a newbie in the right direction?

Thanks

Andy

Hi,
A possible way would be to build a concave or convex mesh, and then apply your renderer as a texture on it…

Ah, that would make sense, so you would just build a mesh inverse to the desired area and then render the texture onto the mesh? Is there any tutorials you would recommend for dealing with mesh’s?

Andy

the way to go would be building exactly the object on which you’re going to project (nothing inversed!), with a texture as explained, and then using a vvvv camera (have a look at the projector module) at the position of the physical beamer. the image you then get is correctly distorted and masked.

building the meshes can become quite difficult, with additional neccesary software like maya, cinema4d or 3dsmax.
but if you just need simple a concave surface, you perhaps can also use vvvv primitives like a sphere (or cylinder), potentially with some texture transformations.

i would suggest to use two renderers. always have an inspector open to be able to give nodes a Descriptive Name. do so for your two renderers. one is your “final output” (looking at the virtual scene from the point of view of a projector), the other is your “overview” renderer (which gives you a view onto the scene from another flexible point of view).

please check out the modules:

  • Projector (EX9).v4p, which has a Transform input to position your projector in the room (i would suggest to map meters to units in the virtual scene). connect its View and Projection Outputs to a renderer which you should name “final output”.

  • GridEditor (EX9).v4p, which has a FileName input where you should specify a file with absolute path but without extension to be able to store you modifications.

  • use a Camera (Transform Softimage).v4p and connect it to your “overview” renderer and to the grideditor “View Projection”.

if you wonder how to edit points have a look at the help patch of GridEditor (EX9) by selecting the node and hitting F1.

always make sure to look at nodes also with the inspector, which gives you a faster overview what the node is capable of, or what the parameters are.
make sure you read the tooltips before drawing a connection.
you will just get a better feel for it that way. when you know you have to connect two modules with each other prefer drawing connections between pins which share the same name, if two modules offer that.

i would hope that is then more or less just plug and play.

and at the end you will need to put a texture onto the grid…

just have a try. maybe start with rebuilding the help patch for the grideditor or copy and paste…

Thanks for the pointers, I had a play with putting a video texture onto a cylinder which in theory should work, i want to take this further. I was blown away when i saw ales9000 [http://www.vvvv.org/tiki-view_blog.php?blogId=4#234LEA Ceramiche Installation](http://www.vvvv.org/tiki-view_blog.php?blogId=4#234LEA Ceramiche Installation) and found out he used only 1 beamer.
Ive attached patch i came up with just playing about. Looking forward to playing with out those nodes you suggested and the dual renderer Gregsn.

Thanks again

Andy

Video-geometry-mapping.v4p (11.3 kB)