Bart

For a small project, I'm looking for a way to create a multi-surfaces videomapping on some triangular surfaces. Using jit.gl.cornerpin 

 do the trick, but it has (as far as I know) only 4 pins to create a square. For this project, it would be much easier if I could create a triangle and use 3 pins to map it in the space.

Is there a way to do it with jit.gl.cornerpin ? I assume not, because a video is a rectangular. Do you have an idea ? My first intuition would be to slice in a triangular shape my media. But then ?

Hi there,

For a small project, I'm looking for a way to create a multi-surfaces videomapping on some triangular surfaces. Using jit.gl.cornerpin could do the trick, but it has (as far as I know) only 4 pins to create a square.  For this project, it would be much easier if I could create a triangle and use 3 pins to map it in the space.

Hi there,

For a small project, I'm looking for a way to create a multi-surfaces videomapping on some triangular surfaces. Using jit.gl.corn

jit-gl-cornerpin-alternative-to-create-a-videomapping-using-3-corners-instead-of-4

simplest way i can think of is simply draw a triangle with gl.mesh and provide texcoords as desired. you can then capture this to a texture and further process using gl.cornerpin:

Thank you ! Of course, that's a thought, and your exemple can do the trick. Even more, because, I think I don't need to use the cornerpin function for further process. I could only change the coordinates of each corner of the triangle (but I'm loosing the ability to use the mouse directly on the output, but I don't care). I need to dig a bit now ;-)

you can easily hack something together using jit.gl.handle to modify the positions of the triangle vertex:

Thanks a lot for this idea. I didn't get any time to dig more into it, but I will be on it this month.

Using jit.gl.handle can definitely a way to achieve the idea. I will work on it and come back to you with my result ;-)

Thanks a lot for this idea. I didn't get any time to dig more into it, but I will be on it this month.
Using jit.gl.handle can definitely a way to achieve the idea. I will work on it and come back to you with my result ;-)

Hi guys, really cool technique! I figure this can be expanded with a polygon draw_mode to allow for more complex mapping, but after messing around with it I find that figuring out the proper texture coordinates for different amounts of vertices is not very intuitive, actually I can't figure it out at all! It's all looking very kaleidoscopic to me. Any pointers?

Never mind, this article all made it very clear. 

https://learnopengl.com/Getting-started/Textures

It works super well! I'm getting ideas to expand this with draw mode quads to allow for multiple rectangles, poly~ to easily change the number of corners, and update texcoords automatically. Will post the results if I end up putting in the time. I'm going to do projection mapping of an oval scene soon, I suspect it would be possible to use jit.gl.gridshape @shape circle with some scaling to make the same technique work there. With the old projection mapping patches getting discontinued, I'm very happy to have found this approach.

Never mind, this article all made it very clear. 
https://learnopengl.com/Getting-started/Textures

It works super well! I'm getting ideas to expand this with draw mode quads to allow for multiple rectangles, poly~ to easily change the number of corners, and update texcoords automatically. Will post the results if I end up putting in the time. I'm going to do projection mapping of an oval scene soon, I suspect it would be possible to use jit.gl.gridshape @shape circle with some scaling to make the same technique work there. With the old projection mapping patches getting discontinued, I'm very happy to have found this approach. 

jit.gl.cornerpin alternative to create a videomapping using 3 corners instead of 4 ?