I have a GeForce GT 8800 and I wanted to use hardware multi sampling but when I do this:



int pixelFormat;
UINT numFormats;
float fAttributes[] = {0,0};

int iAttributes[] = { WGL_DRAW_TO_WINDOW_ARB,GL_TRUE,
WGL_SUPPORT_OPENGL_ARB,GL_TRUE,
WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB,
WGL_COLOR_BITS_ARB, 24,
WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
WGL_SAMPLE_BUFFERS_ARB, GL_TRUE,
WGL_SAMPLES_ARB, 2,
0, 0};

wglChoosePixelFormatARB( rendertarget->hDC, iAttributes, fAttributes,1, &pixelFormat, &numFormats);
SetPixelFormat( rendertarget->hDC, pixelFormat, NULL );


I am unable to render anything. I checked to see if the extension was supported and it does not appear to be supported. How do games like Half Life 2 do multi sampling if it's not supported by my hardware? I assume there must be a trick to do it without hardware support?

Your hardware does support multisampling, and you should see GL_ARB_multisample in the extensions string. Support for any OpenGL version of 1.3 or later also implies support for multisampling even if the extensions string doesn't show it.

[quote name='SteveDeFacto' timestamp='1313304213' post='4848871'] How do games like Half Life 2 do multi sampling if it's not supported by my hardware?

Create a multi-sampled framebuffer object (Using ARB Framebuffer). Render into it. Resolve (i.e. downsample). Use the resulting colour texture to draw a fullscreen textured quad.
[/quote]

Hi, I've long since resolved this issue though your reply sounds like there may be a more direct way then what I am doing. Right now I have two frame buffers, one for multisample rendering, and one for texture rendering. I blit the image from the multisample FBO to the texture FBO so I can use that one to render to a texture. Is there a way I can get a texture from the multisample FBO without needing to copy it to another frame buffer? It would allow me to cut one extra step from my rendering pipeline.