tomslater

I have drawn simple square and want to know the x,y,z coordinates of each vertex as it rotates. I know that jit.gl.sketch does not support matrix output, which would have helped me.

So I'm trying to rotate the square by moving the vertices manually instead of using glrotate. I've had limited success with poltocar, in rotating one vertex. See patch

I'm stuck on how to rotate the remaining 3 vertices while maintaining the square shape.

rotating-vertices-with-poltocar

one method could be the use of "jit.matrix" to generate vertices, and using the great "qrot" in "jit.gen"...

Hi,
one method could be the use of "jit.matrix" to generate vertices, and using the great "qrot" in "jit.gen"...
look  this patch :
mathieu


I can only seem to look at one vertex transforming . I would like to be able to see the movement of all four of the square's vertices.

I added something to your patch that usually works for me but not this time, any ideas?

you can find the 4 vertices position like that :

This works great, but I have one final question about the order of vertices:

As I understand it, vertices are numbered counterclockwise.

The order of vertices in your patch is confusing me?? they are:

vertex 2 = -1 1 0 (should be top right, but is top left)

vertex 3 = 1 1 0 (should be top left but is top right)

Somehow these coordinates come from a correctly drawn square, but if I use these same coordinates in a script directly to jit.gl.sketch I get a crossed shape like two triangles.This is confusing matters in my patch.

Sorry for my weak knowledge, I am kind of new to Jitter and OpenGL.

Please see the patch as an example of what I mean.

The order of vertices in your patch is confusing me?? they are:
vertex 0 = -1 -1 0 (bottom left)
vertex 1 = 1 -1 0 (bottom right)
vertex 2 = -1 1 0 (should be top right, but is top left)
vertex 3 = 1 1 0 (should be top left but is top right)

this vertices order is how "jit.iter" itering matrix...

So you can draw primitive in "quad_grid", otherwise you can use "zl.lookup" to reorder vertices...

hi,
this vertices order is how "jit.iter" itering matrix...
So  you can draw primitive in "quad_grid", otherwise you can use "zl.lookup" to reorder vertices...


Your help is much appreciated, thank you


Rotating vertices with poltocar