A simple example of how 3D design and photo-realistic rendering works
Within the 3D design environment, a wireframe drawing of the object is created:
The level of detail included depends very much on the item. In this example the detail around the wheels is needed to ensure a realistic end result is achieved when the item is rendered.
Once the detail is in place in the 3D model, appropriate surface textures and colours can be applied. There is a large range of surface materials such a chrome and different types of leather or faux leather and colourways that can be applied.
Surface detail added to the model is done to scale so that a large, high resolution view of the item is shown as realistically as a smaller view:
The resulting rendered image can then be stored for use on a webpage or it can be incorporated as a part of a scene. Items can be easily duplicated and lighting and surface material and colour changes, easily put in place.