Original Post
I found a sky simulation that looks good when using HDR, but not very good without HDR. I'd like to incorporate a technique similar to the HDR rendered sky into my own application, but I don't know how to incorporate it into an application that isn't using HDR for any of the other components of the scene. Assuming I render the sky only to an offscreen surface for the HDR stuff, I can then project it onto the frame buffer by rendering a quad, but then I don't get correct depth value comparisons with the rest of the scene, which may occlude the sky. For that to work, I would need an entire extra z pass, which would reduce performance a lot. The second alternative I can see would be to try and make the entire application HDR, but that would be extremely complicated for me as I've got water reflection effects and similar that would need to be mixed into all the HDR stuff. Are there any good ways around this? I haven't yet seen any non-HDR sky rendering technique that looks good enough, but if there is one it would probably be the best solution. Technically, the HDR colors will eventually end up generating normal color values anyway, so shouldn't there be appropriate functions for HDR rendering without using the traditional approach? As far as I can see, the only thing HDR adds that couldn't be added as easily in a single pass is the bleeding of light colors to neighboring pixels around extremely bright objects. [Edited by - all_names_taken on August 3, 2006 5:25:28 AM]