First of all, the final version of the Gengar alleyway render is done, you all should go admire it: http://j-the-ninja.deviantart.com/art/The-Malevolent-Presence-of-the-Shadow-Alley-402947648
Now that we got THAT out of the way, someone on r/blender asked for more information on the fur. I figured that was a subject worthy of a blog post itself, since i doubt they’re the only person who might want to know.
Let’s back up a bit and have a look at the modifier stack on the main Gengar mesh. (that’s the one making up the purple bits of the body and the insides of the mouth. Eyes, teeth, tongue, and claws are separate meshes)
It looks like this:
The first item is the armature modifier. I left this collapsed to save space, but it’s just pointed at the main rig and set to “vertex group deform” mode. So the first thing we do the base mesh is deform it to the pose.
Next are the subsurf and displace modifiers. I modeled Gengar out as a fairly low-poly base model in Blender, then sent it over to Zbrush to detail it out a bit (you can see that in the WIP threads linked a few posts back). He had a good number of subdiv levels over there…5-6 or I think. Obviously I’m not sending a few million polys back to Blender to try and rig it, so what I sent back instead was the slightly deformed (by the sculpt) base mesh along with a matching displacement map of the remaining levels.
The subsurf modifier here puts back 3 of the subdivision levels, then the displace modifier uses the displacement map from Zbrush to put things back into place the way they were with the sculpt. I had a few issues with thin parts of the mesh not displacing properly, so I made a vertex group (disp_clear) that included all other verts, and locked the displacement to those. So here we have the equivalent result to the level-4 mesh in Zbrush (remember, level 0 in blender is level 1 in ZB). Notably, this is done AFTER the rig. Not only is this a lot faster, but it makes weight painting a lot simpler because the subdivision naturually smooths out crooks and creases made by the mesh. (there’s a normal map in the shader to handle the last few levels, btw)
So now that we have our render-level mesh ready to go, FUR!
The first particle system is the guard coat. This is an even, fine, all-over coat that forms the base fur layer. It looks something like this, and is pretty much all the fur you see on the front and limbs:
My main goal with the guard coat was to make him look natural, and break up the character outline. Gengar draws a good bit of inspiration from “shadow people”, who are often depicted in pencil and ink drawings, giving them a very rough and broken up outline. My goal with the guard fur was to duplicate that spiky, undefined outline.
Since the guard coat covers the whole body, there needs to be A LOT of hairs here. This is a pretty common mistake I see in a lot of renders, especially using the hair in Cycles. Big, wiry, sticks of hair. A full fur coat requires A LOT of hairs. Both base/parent hairs (to evenly cover thin areas, I used 15k), and a lot of child hairs to fill out the coat. Gengar’s guard coat contains 1.35 million strands. This might be a bit excessive, it doesn’t look THAT much worse with about half that many child hairs, but I had the RAM and wanted this to look good. It’s not included in the screenshot here, but all the hair systems here use a root-width of around .05-.07. A lot of people use far too large of hairs to try and save performance, and it looks awful. Smaller root size, more child hairs. Memory use be damned. This is a hero asset, make it look good!
The child settings deal primarily with getting the right look of the coat. I wanted it to look somewhat coarse and ragged, so I added some clumping and roughness noise to the hairs as well. The main part of getting it to look ragged is to just mess it up with the brushes in particle mode. I like taking the basic comb brush at a low strength and just flinging my wacom pen around a bit.
This is a much different setup to the guard coat. You might notice there are only 400 parent strands, and no particle mode use. When you use hair clumping, each clump forms around a single parent. (by default, virtual parents can be used to fine-tune this). This setup uses a few parent hairs and A LOT of children to get a series of spiky clumps.
The character artwork for Pokemon is done anime-style (for lack of a better term) and leaves it a bit ambiguous just what those spiny things on Gengar ARE exactly. I went for a combination of black horn-spikes, and spiny fur. This particle system represents the major part of the latter. You’ll notice that the clump value is shoved all the way up, and wave-kink is enabled. The “kink” option alter the behavior of individual hairs and clumps. Wave introduces a jitter to each hair. I also added a little bit of random-rough so it would look more “demonic” (again, like the guard coat, the roughness breaks up the outline giving him more of the “hand drawn ghost” look). It’s collapsed in the settings here, but the reason I enabled advanced-hair options on this one was to get ahold of the random-velocity control on Blender’s particle system. When used on hair, this introduces a random factor into the direction parent hairs grow, which is otherwise straight along the normal. This was, the spikes point in all directions.
The setup and purpose are pretty much the same as the back spike hair, this is just an extra system to fluff out the tail a bit more.