I've made a little script that converts GTA IV materials to Standard materials, and shader blend to GTA SA/VC/other games compatible vertex alpha blend.
It needs GIMS IV to be installed.

Run the script, select GTA IV imported models, and press the "Convert" button.
DOWNLOAD===
Just a little screenshot of converted from IV to SA terrain piece, that's exported to DFF using the Deniska's script(doesn't exported fully proper - need to fix it)...
This post has been edited by 3Doomer on Saturday, Feb 18 2012, 19:23