I have a dilemna and since many of you probably sell your work for a living, maybe you can help me figure this out. I am designing various products that utilize my artwork and I plan to sell them online. However some of the models used in them were created by other designers. I have two examples. In the picture provided, the architecture of the room itself (pillars, arches, doorways, etc.) was created by another designer and posted in the free section of 3D Cafe. I have checked both the website and the readme files within the model file, and neither state any copyright of any kind. I have removed various origional ideas and redesigned the space from the ground up, including creating all my own materials for every current aspect of the room. The staircase has been added and is also another free model from 3D Cafe, again with no copyright notice. Again, I have applied my own custom material to the staircase as well. Can I sell this design as an origional idea, without being nailed for copyright infringement? If you compared this to the origional model you would be hardpressed to see any similarity, except a general likeness in certain architectual details. You could say the origional inspired this creation. The second case uses one of the models included with Vue, the house on stilts, with the pointed roof. Again, the materials have been altered, although no design changes occurred. This was included in the purchased program, so am I legally entitled to use it in an origional creation, without being charged with copyright infringement? What constitutes copyright infringement when it comes to using either free or purchased models?? If I change all the materials, but keep the overall design intact, can I incorporate that idea into my artwork and sell it as my own?? All help is greatly appreciated, as always. Thanks.