PDA

View Full Version : Windows 7 OpenGL Texture Distortion



talley301
11-18-2009, 03:52 PM
My 3D App has worked fine in XP and VISTA. In Windows 7, large flat triangles or quads textured with a tiled bitmap look fine when viewed straight on. When viewed at an angle the various tiles appear at different angles crating a strange distortion which changes depending on the viewing angle. I use the DirectX SDK (June 2007) since the newer versions no longer include DirectSound.

Alfonse Reinheart
11-18-2009, 05:22 PM
Did you turn on perspective correction?

talley301
11-19-2009, 06:00 PM
Thanks for your response!

I set perspective with ::gluPerspective(VIEW_ANGLE, aspect_ratio, 1.0f, 1000.0f); where VIEW_ANGLE is 32.0f and aspect_ratio is the aspect ratio of my window, 1.74 at present.

The did not use GL_PERSPECTIVE_CORRECTION_HINT or glFrustum().

talley301
11-19-2009, 11:57 PM
I was able to fix it with

::glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

Thanks Alfonse for the idea!

mfort
11-25-2009, 03:21 AM
Fortunately, the glHint is removed from OpenGL 3.2 Core.
It only makes troubles, vaguely defined, implementation dependent, no defaults set. Big relief it is gone.

talley301
11-27-2009, 02:53 PM
Unfortunately, I just discovered that, while glHint solved the distortion problem, it also made my rendering dog slow when I made my window full-screen. In fact, my animation frame rate fell from my desired 18 frames per second to about 4.

I checked the driver, and Windows 7 claims that I have the latest driver for my video card.

ZbuffeR
11-27-2009, 03:29 PM
And your card is ?
Driver version ?

talley301
11-27-2009, 04:59 PM
Graphics Card: Radeon X1300/X1550 Series
Driver Provider: ATI Technologies
Driver Date: 4/24/2009
Driver Version: 8.56.1.15

Stephen A
11-27-2009, 05:44 PM
Have you downloaded and install drivers from Ati's website (or your manufacturer's website if this is a laptop)?

If not, you are getting OpenGL emulation via Direct3D. In case this is not obvious, yes this is very bad.

talley301
12-03-2009, 01:20 PM
ATI no longer supports new drivers for my card, so I am stuck with the Microsoft driver. My conclusion is that I need to buy a new card. I am considering the FireGL 3100, 3200, or 3600 for which ATI does supply a Windows 7 driver.

skynet
12-03-2009, 03:26 PM
http://support.amd.com/de/gpudownload/wi...mp;lang=English (http://support.amd.com/de/gpudownload/windows/Legacy/Pages/radeonaiw_vista32.aspx?type=2.4.1&product=2.4.1.3. 7&lang=English)

Seems a few months newer than yours?