Hi Wojtek, On a cursory read of your email it does sound like glTexParameter GL_TEXTURE_MAX_LEVEL would be worth setting. It'd be interesting if this along with changes to the dds plugin would solve the problems you are seeing.
Robert. 2009/6/3 Wojciech Lewandowski <[email protected]>: > Hi Robert, > > I believe I have found a bug in DDS loader. DDS images can have lower number > of mipmaps than it would require. But current DDS loader allocates storage > for all mipmap offsets but only reads mipmaps that are stored in > DDS. Offsets for missing mipmaps are set to 0. One could say thats this is > correct but I cannot agree. Full length mipmap offsets vector is a reason > that Image::getNumMipmapLevels() returns number showing that mipmap chain is > full. This in effect is a reason that Texture apply attempts to load these > missing mipmaps. Next step is a pair of Image::getMipmapData & > Image::getMipmapOffset functions which return addres and offset of main > image for missing mipmaps. So in effect missing mipmaps will be incorrectly > loaded from main image pixels. > > But the story does not end here. When I tried to fix the loader to allocate > and read only available mipmaps I encountered a strange problem. > Textures using such incomplete mipmap chains were drawn blank (all white). I > started digging and I have found that if not all mipmaps are loaded for > texture then mipmap filters may not work. In my case it was more extreme > because this particular texture was completely not working, but I expect > that if code was incorrect driver did not need to behave predictably. Then > I found that it is allowed to use lower number of mipmaps in OpenGL but one > has to set glTexParameter GL_TEXTURE_MAX_LEVEL to last available mipmap > index. I did a search in OSG and currently this parameter is not set. May we > add this ? > > Cheers, > Wojtek > _______________________________________________ > osg-submissions mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > > _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
