The code I was looking at freed the buffers during initialization (before any paint operations). That might work better if there's no additional buffers being created, but it's probably not ideal.
Do you have anything like that in your code? Thanks, -- Raul On Sat, Feb 29, 2020 at 12:41 AM Thomas McGuire <tmcguir...@gmail.com> wrote: > I added your tetrahedron object data into my test file for shader.ijs. The > goal was to get a tetrahedron and a cube up there rotating. What I got was > 2 badly formed tetrahedron rotating. I had thought from my reading that the > shader should keep these entities distinct. > > I don’t know why I can’t keep the shapes distinct. I have a feeling the > vbo buffer is not working the way I think it is. Or the kernel needs a > different vertex/color variable for each object. > > I tried changing the definition of the tetrahedron a bit. I suspect that > it has to do with the shuffling of the vertex data to create the faces. But > I can’t come up with the right vertex ordering to make the faces line up > either > > Tom McGuire > > > On Feb 28, 2020, at 2:09 PM, Brian Schott <schott.br...@gmail.com> > wrote: > > > > Thomas, > > > > I agree with Bill that this is a great step forward in understanding how > to > > use opengl. > > > > My main interest is in doing a turtle graphics app which enables multiple > > turtles to appear on the screen. In the previous version I had to keep > > track of the position and heading of each turtle for each of the user's > > moves. > > I am mostly thinking of your use of glu_Lookat to translate the turtle > and > > rotate the turtle. I am toying with the idea of replacing the Eye in > glu_Lookat > > with the current turtle's heading. But I really need to think about this > > more and could use any ideas you have. > > > > Of course I am still struggling with painting the faces of the > tetrahedrons > > as solid colors. They are my tentative turtles. I am now wondering if my > > problem is related to the use of four-element color vectors instead of > > three element. I have not found any description of how to set those > things > > in the kernel as you seem to have done. And does this setting conflict > with > > the attribute setting that I changed from 3 to 4? > > (B=) > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
