As mentioned, this is called "Patternmaking".
It might seem pricey (I purchased it for $45) but unlike many pattern making books, this book includes detailed instructions on drafting a sloper from your own measurements. (Most start with a basic standard size, or suggest starting with a purchased sloper).
It also has excellent, clear diagrams on manipulating patterns. The Photos and layout are appealing and very clear. To top it off there are some wild and inspiring sample designs in the final chapter.