Sorry for my English It should be rather "better performance in all simulations" LOL. Forgive me that i don't have time to make a tutorial... But - say you want to model a house and have 2 textures for walls and one for roof. Instead of using three textures, you can place all of the pictures on one texture (and this is called "texture atlas") and attach this to model. In Sketchup you have to select some polygon, right click it and choose "Texture - position". Then you map the polygon. You can easily find videos on this on YouTube. This way you have to map all of the polygons of your model (there are a little more sophisticated ways also, but for simple model this works enough). There is more - you can have texture atlas with pictures of another objects and use it for more models! This way you can have just one material for multiple models This will help to the performance a lot! The most important thing you have to do in xpacker after importing your objects (which all use the same texture) is to merge all their materials into one. XPacker always creates new material with new object imported. The trick is that you import your models (couple materials appear in xpacker), then (or before, does not matter) you create new material (click "Add from textures") and assign this material to all objects. This way they all will use the same. If everything goes right, at the end you can delete unused materials and textures (all textures will be the same, but in different folders) to make the xpack smaller. Tip - to assign material to objects in XPacker, copy (Ctrl+C) the path of this material, select object, go to it's material path and paste (Ctrl+V - there's no right click). The material will be replaced. You have to do this for all objects one by one. Takes a little time, but this is the only acceptable way to make good xpack I hope it helps PS. Don't forget to save the Material.