For something like this I would normally create a toon render with pwtoon or even just a normal render that uses the default grey material, then set the opacity of the rendered image down to something like 25% in Photoshop or a similar program, print it out, and draw over the top. Alternatively I sometimes skip changing the opacity and just draw over the image on tracing paper because it’s easier on the eyes. As far as I know not even higher end 3d programs can do exactly what you want although it would be damn great if they could.
a bit off topic but how do the visual style shaders compare to pwtoon? Would it be worth picking them up if you already have pwtoon or do they do pretty much the same thing?
Hi there, i’m the creator of Visual Style.
There are a couple of big differences between pwToon and Visual Style.
pwToon is a mostly automated shader, with your shader colour being automatically multiplied over the base colour. This makes it harder to create zany colour combinations, as the shadow colour you set will always look different in the final render. Visual Style is more of a manual shader; it requires quite a bit of tweaking, but you get more control over the final look (the colours you set will look the exact same in the final render). On the other hand though, pwToon is the only toon shader out there with support for even-width lines (although they do take a long time to render), so that’s exclusive to pwToon. Visual Style’s only “exclusive” feature is the use of Ambient Occlusion for more detailed soft shading (it’s heavily inspired by Visual Novels/Dating Sims).
EDIT: @Chris: Re-reading this topic, it sounds more like you’d benefit from an M4 with a custom texture that is literally just the outlines of the main muscle groups with no shading whatsoever. If you buy the muscle maps, you could trace over them in Photoshop to create the new ‘guide’ texture.