Hi John
Welcome to WTP.
Lloyd Johnson has put together some great software for designing segmented vessels. Take a look at the tutorial vids.
If you have not purchased the software can be download and used for 30 days free.
I have been using WTP for years. It gives you full control each ring.
SP is great for painting designs and has many great profiles to choose from.
There are times I design something in SP and rebuild it in WTP for final tweaks. Due to the databases one cannot import WTP files to SP or vise versa.
The forums are a great place to ask questions as you begin your journey in segment building and turning. Have fun.