I'm not sure what you are asking about.
I have made several 3D items over the years and as far as patterns, I've just drawn my own. I draw a picture of what I want the front to look like and another picture of the side and apply the pattern on the wood and start cutting.
You sometimes have to tape the drop off pieces back into place for doing the side view on the saw.
I have made chess pieces like that copying the pattern several times on a copy machine. Some times the front and side are the same shape which makes it easier like these salt and pepper shakers.
I have also just drawn the pattern directly on the wood and cut it as in the "Fish key chains"
If you are asking about how to make patterns on the computer, I have no idea!