Re: Large textures getting soft

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Dewey Anderson (dewey++at++evt.com)
Thu, 29 May 1997 18:35:08 -0600

On May 29, 12:42pm, Dirk Reiners wrote:
> Subject: Re: Large textures getting soft
> On May 28, 1:19pm, Dewey Anderson wrote:
> > Subject: Large textures getting soft
>
> >......(munch)
> > The problem is that textures that have a dimension of 1024 come out soft,
as
> if
> > they've been filtered. I've got two rectangles with textures on them. The
> > rectangles are 511x486 and 720x486 in size and have textures applied to
them
> > that are 512x512 and 1024x512 in size respectively. I'm setting the
texture
> > coordinates so that one unit of texture = one unit of rectangle = 1 pixel
on
> > the display.
>..........
>
> Another thought: OpenGL has a limit for the dimensions a texture can have. I
> don't know about Octane, but when we exceed the limit on out iR (2048) the
> texture is just scaled down. Try to put a 'printf("Max texture size:%d\n",
> glGet(GL_MAX_TEXTURE_SIZE));' somewhere where OpenGL commands are legal (draw
> callback or so).

Say Hallelujah! When I do this, it comes back with 512. That certainly seems
like the problem.

Now the question is, what sets that limit? Is this something I can change to
1024? And can anybody verify that this would cause filtering?

(I guess I'm still puzzled, because when I do this in my little test program,
it ALSO says 512, but there is no softening.)

BTW, I do have the MINFILTER set to MIPMAP_TRILINEAR but since the pixels and
texels are the same size, I wouldn't think this would come into play.

Thanks to Dirk & Dirk for replies.

Dewey Anderson
dewey++at++evt.com
Evolving Video Technologies

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