Re: [PyOpenGL-Users] Problem with numpy arrays and OpenGL textures

[Adeola B. <the...@gm...>]

Well,

Now I have a recognisable image that just seems to be "twisted funny"
(not again...), after I decided to use GL_UNSIGNED_BYTE instead of
GL_FLOAT. I think the strange orientation of my picture might just be
due to placing the corners in the wrong order or some such. Last time,
I resolved the whole "twisted funny" problem with an offset of +/-1.
It's also a bit dark, but that's definitely fixable. Here's a picture
of the "funny looking" image to compare to the "good" image I sent
earlier.

Thank you so much for all your help - I think the ctypes call made the
difference between rendering gook and rendering the texture.

Adeola

On Jan 5, 2008 5:03 PM, Mike C. Fletcher <mcf...@vr...> wrote:
> Adeola Bannis wrote:
> > Thanks Mike,
> >
> > It wasn't so much a script I sent as a class definition. There
> > probably should have been some main function for testing, but I didn't
> > feel like writing up the wxApp.
> >
> > I don't currently have OpenGLContext installed, so I can't (yet)
> > directly run your code.
> > The +1 in the dimensions were necessary in my code before, at least in
> > the horizontal direction - otherwise the image had a characteristic
> > "twist".  I had already tried it without them, but with little
> > improvement. If you're interested I've attached the image I get with
> > pylab.imshow() and the image I get on my GLCanvas.
> >
> > I tried the image.ctypes.data_as() conversion, but then my program
> > segfaults whenever it gets to the gluBuild2DMipmaps call.
> >
> The problem I'm having here is that I can't reproduce your failure, as
> your code doesn't seem to include the failing code (though as I
> mentioned, the off-by-one dimensions are suspicious).  I've got my
> float-based image displaying properly with the code I sent you.  The
> most likely sources of segfaulting is that you're passing a
> non-contiguous array, or you are passing dimensions that are too large.
> Either one will cause OpenGL to overstep it's array bounds.  In your
> code you are calling contiguous and then throwing away the result IIRC,
> any chance you intended to use those results?
>
> Good luck,
>
> Mike
>
> --
> ________________________________________________
>   Mike C. Fletcher
>   Designer, VR Plumber, Coder
>   http://www.vrplumber.com
>   http://blog.vrplumber.com
>
>