Never forget that changing the renderengine will produce different looking pictures as we know them from the actual Bryce and the versions before. What if you want to render a scene you created before with the old Bryce? What if you do it professional and need exactly the same look again for a client? I think it would be better to have the renderengine as a engineplugin. So you can have the old engine with some speedups but the same results and other renderengines if you like them with more advanced featuresets and more. The same with the textures. You can create new textureengines as plugin..no problem. But you should be able to use the old too. Thomas