Fun (?) with Fur (Day 4)


With the rabbit more or less fully formed (for the purposes of this project), the next logical step was to give it fur. In Blender, this is achieved by creating a particle system and assigning it to the object. There are many different types of particles, but the obvious choice for a rabbit’s fur is a system of hair particles. My approach to this was the same as it is for everything related to development: get it done first, then worry about efficiency and appearance. Pictured above is therefore the result of a single interpolated* system comprised of at least twenty thousand hairs, and I only edited their length. The appearance of the ears led me to christen the rabbit Splotchy the Eldritch Hare. Little did I know at the time how well the name would fit.

*In a particle system, particles can have sub-particles known as children that mimic their appearance and behavior. Instead of creating a system that emits 10,000 particles, for example, you can achieve the same result with a system that emits 1,000 particles with ten children each. Children can either be simple or interpolated. The difference in this case is basically between the possibility of hairs being generated in the space around the rabbit and ensuring that hairs come only out of the “skin.”

Style, Render, Repeat (Day 5)

The result of Day 4’s work was more or less just to give me an idea of how the fur looked before I did anything to it. That’s what I tell myself now, anyway. The first actual order of business was to assign materials to both the skin and fur so that Splotchy wouldn’t be gray when rendered. I gave the former a Diffuse BSDF (bidirectional scattering distribution function) shader, and the latter a Hair BSDF shader. These affect how the materials look when rendered in Cycles as opposed to in Blender’s internal renderer. Without going into too much detail, Cycles is better for photorealistic models and scenes, the diffuse shader helps to determine the skin’s color, and the hair shader helps the fur look like, well, fur. I made the skin a light pink, and I made the fur black. Initially, the rabbit looked like this:


There were two main problems. I saw and addressed one almost immediately. The other one went unnoticed for several hours despite it staring it me in the face, but more on that later. It was at this point in the process when I started using Particle Edit mode for the first time. Like sculpting, particle editing provides several different brush options. I used three: Comb, Add, and Cut. Their functions, I think, are more or less self-explanatory, but the mode itself is not because it limits both what can be edited and how it can be edited. First, the view when using the mode is not the particles themselves but general representations of them (see below). This means that it’s not possible to see exactly how actions performed on them affect their appearance without switching into another mode.


Second, once in Particle Edit mode, it’s no longer possible to edit the number of particles emitted, only the number of children each has, at least without switching to Object Mode because the Add brush option performs a similar function. If any of the brushes has been used, then the only way to edit that number at all is to select an option in Particle Edit mode called “Free Edit,” which then undoes everything done in the mode. These made the process more incremental in terms of progress than it had been up to this point because it required a lot of minor changes and toggling between modes to achieve something that looked at least passable. I was also still editing a single particle system for the entire rabbit, so I ended up creating more problems than I solved:

The dark patches indicate areas where the fur has not been combed. It’s still in the default position.
The area on the back is related to the second problem I mentioned (no, it’s not leprosy).
Splotchy’s covered in far too many hairs, but he’s not sentient enough to mind.

The Joy of Weight Painting (Day 6)

Eventually, the proverbial clouds parted, and I saw sense. A single particle system for an animal’s fur was impractical, somewhat unwieldy, and definitely excessive. I could instead use multiple particle systems, one for each part of the rabbit. They could be manipulated independently from one another and cut down on the total number of hairs, so it was a win-win. All I had to do was create vertex groups that I could then assign and define by painting different areas of the model. By default, the entire mesh has a weight of zero and a blue color. Weight is on a scale from zero to one and on a spectrum from dark blue to bright red. In the case of particles, it determines the percentage of them that will appear on a vertex group. I started with the body, which would have the most fur, then moved to the head and the mouth area (see below).  In so doing, I also fixed that second problem with the initial render. I most likely didn’t assign the skin material to the skin after creating it, so the material it had was that of the fur. The distribution of the fur in the second-to-last image in the previous section was too thin on the rabbit’s back, so the skin was visible. I just didn’t notice because it wasn’t the light pink I expected it to be.

That patchiness on what I guess would be the shoulder bothered me more than it should have.
I didn’t proceed to the next vertex group until I was satisfied with the one I was working on.
I think it looks much better than the initial attempt, but that’s not saying much.
Between this and the final image (i.e. the featured one), I spontaneously decided to make the mouth fur lighter.

Embattled with Ears Again (Day 7)

I didn’t plan this, I swear. When I painted the ears in Weight Paint mode and then styled the fur in Particle Edit mode, I kept getting bald patches on either the tops or backs of both no matter what adjustments I made (I apologize for the lack of visual aids), so I manually selected their vertices, made that selection a vertex group, then assigned it a weight of one without actually painting anything. The result, after combing the fur, was what’s in the featured image. It’s the best I was able to achieve after a couple hours of work, and I thought it was good enough for the time being. It may be good enough, period, depending on whether I can make the ears look better without remodeling them. That would be a last resort given how long they took to make compared to everything else thus far, but either way, I’ll have made a decision by the time the next entry in this series is written.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s