I've been successful using texelFetch and other modern GLSL functions. Be sure to declare the GLSL version that you need in all your shader programs. For example, here is the first part of a vertex program in an .JXS file in which I used the texelFetch() function. *Important* you must have the compatibility profile declared for Max to function. Max must have the compatibility profile's support for old-style built-ins like gl_Normal, gl_Vertex, etc.