[osg-users] Render a huge image (30.000x30.000)

[Filip Arlet]

Hi,

Depends on what you want to do. If you want to render big resolution image, you would have to use tiled rendering. Using PBO for transfering data back could help speeding things up. But in most cases you are rendering non RT image (its too big you cant even save it in RT). Then you just need to compose the big image. Beware of Memory Consumption: 4 bytes per pixel 30000 x 30000 pixels is more than 3GB of memory. 64bit program recommended. in this case whole data will only be on CPU.

If you want to use it as a texture, I recommend splitting the image. You can precreate mipmaps or miniatures. The biggest problem is memory usage. Even if you split textures, you have big problem maintaning all your texture data, in this case you would propably have only 3 bytes per pixel, but its still ALOT. You can use texture compression to lower that value. But then again, this texture size is so big, you wouldnt propably use it all at all times. You can use some kind of texture paging - load miniature when zoomed out and load tiles when zoomed in.

Cheers,
Filip

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