View Full Version : How save wide image ?

05-05-2012, 03:26 PM
Hello everybody :)

For my job I'm loading meshes with several high definition textures in OpenGL.
Purpose being to save the result in a file. the picture must have the highest possible definition. Minimum 4096 x 4096, but ideally 16384 x 8192.

My questions :
Is it possible ?
If yes, which OpenGL function can do that ?

Thanks for your help

05-05-2012, 04:42 PM
Render to an FBO to have a larger-than-screen resolution. Max will depend on your hardware, 4kx4K should be doable on a proper video card.

05-05-2012, 05:04 PM
If you don't run into driver issues, even 16k x 16k is possible on any recent card. Besides that, do what ZbuffeR suggested.

Dan Bartlett
05-05-2012, 11:57 PM
If you want to render to a resolution larger than the hardware you are choosing to target supports, you could use tiled rendering, where you render the scene multiple tiles adjusting the projection matrix to capture a different part of the scene. I haven't done it myself, but here's a link that seems to explain it: http://www.bluevoid.com/opengl/sig00/advanced00/notes/node31.html , and another that appears to do the calculations for you: http://www.mesa3d.org/brianp/sig97/offscrn.htm#tile

05-06-2012, 05:32 AM
Many thanks for the replies :)

I will study all this tracks.

to Dan Bartlett : tiled rendering is what I was doing in VB6, but the limitation of 600Mo for the use of memory, make me going to learn C++ with Qt. Now I try to go further ;)

I will say you more soon.