Thanks for your reply David.
My results seem unaffected by whether I use an ivec4 or the float version of vec4. I used ivec4 because the author of renderwriterhdr.cpp left commented shader code for the conversion from RGBE to float with the ivec4. Check out readerwriterhdr.cpp line 80 to see what I'm talking about. I am in fact using RGBA8 textures. At first I suspected that no filtering was being applied so I tried using osg::Texture::NEAREST with the RGB8 LDR texture for comparison. Although it became more blocky looking as expected, it still look reasonable. This is in sharp contrast to the RAW texture which shows dramatic artifacts. For quick reference: RGB8: http://img162.imageshack.us/img162/8467/hdrrgb8rn7.jpg RAW: http://img206.imageshack.us/img206/8574/hdrrawza9.jpg Any insight is appreciated, Michael Guerrero ( Delta3D ) ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of David Spilling Sent: Tuesday, November 06, 2007 1:59 AM To: OpenSceneGraph Users Subject: Re: [osg-users] HDR - RGB8 vs RAW Michael - With the option "RGB8" ( osgDB::ReaderWriter::Options( "RGB8" ) ) o The image is converted to LDR before being stored in a texture. Doesn't that defy the whole point of being HDR to begin with? Yes, although it allows you to at least read in RGBE / Radiance format files, so that you can use HDR assets in LDR pipelines. That's one thing we fall back to - we generate and ship all our assets in HDR, but depending on the eventual hardware, it may fallback to an LDR load if the card can't handle it. The problem is that my rendering results are different. Firstly, why "ivec4" in the textureRGBE code? If you try just "vec4" does it get better? I would have thought you wanted floats here... Secondly, could this be an interpolation issue? Is the texture format RGBA8 or 32F (I would have thought that you would be using RGBA8, but you never know). Most of the hardware we support doesn't support LINEAR interpolation on float textures, so we have to do it by hand, as it were. Hope that helps, David
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