With the advancement of design software, you have the ability to produce a photorealistic rendering of your designs and use these for marketing or other visual illustrations you may need. This is a prefect tool as it gives you the chance to approach potential customers with a photo of the final product, which can help result in sales.
Photorealistic Rendering will allow you to add the material and colour you eventually want to use for the manufactured part and you will be able to get a visual representation on how it will look before the part is even made. This may give you chance to change the part if you dont like how it looks or simply change the colour or surface texture.
The reason why Photorealistic Rendering was introduced was to try and reduce the cost when it comes to rapid prototyping. The idea is that you can see the part, walk around it, view all design features and make changes if you don’t like it, all this without even making a prototype. Typically I would still suggest you get a rapid prototype made to get a feel for size and functionality but photorealistic rendering reduces the need for more than one prototype to be made.
Most 3D CAD Software will allow the designer to create photorealistic rendering so be sure to speak to him about it and be sure to include some images in the cost of the design.