Cutting Factory’s team is currently working on a music video involving a woman in the desert playing the guitar, and in one of the scenes, she’s visited by a coyote. Everything in the video needs to be built from scratch, although some parts require working with particle systems. If you don’t already know what particle systems are, they are many minute sprites, 3D models, or other graphic objects to simulate certain kinds of “fuzzy” phenomena, which are otherwise very hard to reproduce with conventional rendering techniques.

Understanding the movement

The first thing we do is study images from the movements that an animal makes. Jana from our team did this by looking at two fur flow drawings of a dog in an animal anatomy book, to figure out which direction fur grows on canines (there’s almost no information on Coyotes anywhere because they’re either photographed from a distance or shot dead by hunters – but you can find out a lot by searching about wolves and especially dogs because they’re closely related). Then she sketched over screenshots to figure out how it would look on our 3D model and collected a series of photographs of coyotes from different angles (and similar-looking dogs if there were no good references).

Creating a coyote with particle systems

Translating movement to the screen

Next up, Jana created about 2000 curves on the coyote in Maya, and then converted them to Guide-Curves and then spent some time brushing them one-by-one in the right direction. So now we have theoretically reached the part where we can generate actual fur (which will have to be brushed again, and some noise will have to be added, etc). As for the program, most companies still do it inside Maya (using XGen) but some companies are currently shifting their pipeline to Houdini for CFX and VFX (character effects, like cloth and hair, and visual effects). We decided against Houdini for now, as our team have the experience to do this with Maya.

Creating the rest of the sculpture

As to the general creation process, before anything else, we make a series of coyote sketches from the side view, including diagrams of muscles and bones (based on dog anatomy again, just adapted to coyote form, by looking at loads of reference photos collected from the internet). Then we sculpt it inside of ZBrush by looking very closely at all the references that we had amassed, making sure that things would have the correct lengths and thicknesses in a basic standing pose, with the tail as a straight continuation of the spine (not hanging down). Afterwards, we re-topologized it by hand by (once again) paying close attention to where legs would bend, and therefore, where we would have to place the edges. Then we painted the textures in Substance Painter.

In summary

Essentially this is the same as any other 3D character, except you have to pay a lot of attention to the anatomy if you want it to look photo-realistic in the end – which we do here. Building a character is mostly a “compare the thing to the references and keep working until it looks perfect” kind of job.

We hope you now understand, at least on a very surface level, how working with particle systems functions, especially in the case of building hair for a coyote.