OpenGL rendering errors on Intel HD 3000...

[christianclavet]

Hi, I have a problem with Irrlicht rendering in OpenGl, and was wondering if that happened to any of you and if someone has found something that could help.

I was able to make the game GLSL shaders work and display correctly(I think) on all platform (Mostly the terrain and water, the rest are not using custom shaders). But I'm experiencing some weird clip issue on the Intel Chipset. Tried to use the manufacturer driver and then the latest drivers from Intel (Should support open GL 3.0 and DirectX 10.1). The result were the same. This is the integrated video circuit from inside the Core I3 of my laptop. And it will not that good for my game presentation...

Expected image:
Here is what the display should look like: (rendered from my PC with a NVidia card)


Resulting image:
Here is what the display look like on my Core I3 laptop (Intel HD 3000 rendered):


If you look here, almost everything is ok, except that some frogs are not rendered (or partially), but we can still see their shadows.
The legs of the players are clipped and we can see the effects of the clipping on the circle of the "terrain brush" that is clipped as it's moving on the terrain.

From my searches in the forum; most of the discussions about this was that this could be about "user clips planes". I'm really not sure. Somebody have a way to remove the clipping effect from the rendering? Or it's unsolvable problem?

[hendu]

Can't help on the issue, but if you've already checked your shaders are valid, Intel GL on Windows is notoriously buggy.

[REDDemon]

try do disable all the clipping planes.

or after some digging

http://www.gamedev.net/topic/619053-fix ... 3000-card/

[christianclavet]

Thanks,

I also stumbled on this thread on the gamedev forum.

I disabled all the clip planes (0-5). like that:

Code: Select all

        driver->enableClipPlane(0,false);
        driver->enableClipPlane(1,false);
        driver->enableClipPlane(2,false);
        driver->enableClipPlane(3,false);
        driver->enableClipPlane(4,false);
        driver->enableClipPlane(5,false);

I don't see any difference. Same result. This could be a problem with IRRlicht or the way the card interpret opengl to render a "standard" material over custom shader. With more observation of the problem, I see this: (using the circle of the brush as tool to see how it's being clipped).

- Clip seem to occur in the final render stage (fill) as vertical lines are skipped from the render, If I move the circle over a region that has no custom shader in the background, I can see the rendering complete. (this problem is only visible on Intel)

- As another observation, When rendering "debug" data over "skinned object - with skeletons", the element are clipped because the background is the terrain (custom shader), this happen on all platform (ATI, NVIDIA, INTEL). If I use a standard object (not skinned), the rendering over the custom shader is ok. (ATI, NVIDIA, INTEL). Note that this could be another problem as the rendering is equal on all the platform.

So I suspect that it have something to do with how it's rendered and the INTEL platform is the worst at this. (Look like Intel ZWRITE is getting bogus data)

From the look of this, what I could try next is to create custom shaders for all the models. But this would have to wait after january 31. There is no "quick" way to fix this.

[ACE247]

The Intel HD Integrated cards can do things in DirectX which they can't do in OpenGl. I find that their OpenGL Support is generally quite bad and rather slow.

[hendu]

The Intel HD Integrated cards can do things in DirectX which they can't do in OpenGl. I find that their OpenGL Support is generally quite bad and rather slow.

In their credit, only under Windows. The OS X and linux drivers are done by separate teams each, and have much better GL support (best under linux, but OS X is hugely above Windows).

[ACE247]

Yes I know that, and since Christian is using Windows, that's how it is.