The Shrew
This is an overview of my Shrew character project, and my character workflow in general. I wanted to standardize my personal project pipeline, reinforcing workflows in ZBrush, Substance Painter, Maya, and Unreal Engine 5.
Winter Shrew
Fall Shrew
Concept
This character is separated into the “Fall Shrew” and the “Winter Shrew.” In the story, the shrew is a companion to the main character, who is a squirrel. While the squirrel hibernates well with proper food storage, the other animals are trapped and turned savage by the never-ending winter. The Fall Shrew form is inspired by 3D Platformer type NPCs, while the Winter Shrew draws from stalker characters in Survival Horror games.
Contour and anatomy exploration
Superimposed orthographics
Look and feel concept art
Some quadrupeds, and especially rodents, keep their knees bent in most poses. I thought it would be interesting to exploit this anatomy feature, by having the Winter Shrew stretch his legs and be fully standing. This is exaggerated to tower over the player character and feel unsettled by its resemblance to human posture.
Some references used. I was particularly drawn to the difference in personality when the teeth are exposed. Shrew of this species have teeth reinforced by iron, giving them a striking red look.
Modeling
The Winter Shrew design was going to have many bony landmarks and muscles shown. I also wanted the teeth to be identical between the two as an identification feature. I thought it would be beneficial, both for this project and my learning, to do a full sculpt of the underlying skeleton, and pose it to be sculpted around for both characters. This would also let me identify other areas of the Winter Shrew where bony exposure would make sense.
Fall shrew skeleton and grey model
Winter shrew skeleton and grey model
Retopology in Maya, Fall Shrew - 32428 Tris, Winter Shrew - 47556 Tris
UV/Texturing
My technique for the Fall Shrew was to use an alpha brush to create a normal map of hair. After researching hair options, like hair cards and the fin and shell technique, this method seemed the cheapest and would keep the silhouette closest to the grey model. For this I created a plane with XGen in Maya, and by sculpting the hair on the plane how I wanted, I was able to render out an alpha map to use in Substance Painter.
Hair panel side view
Example Arnold render to be turned into an alpha brush in Substance Painter
Application on surface of the Fall Shrew
The Winter Shrew is accomplished by using multiple layers to represent each layer of skin or skin feature. Starting with a buildup of base skin tones, skin and muscle damage is added next to places with bone expose using the UV distance generator. This generator is warped in other sections of the body to add striations for a raw appearance. Muscles and frostbite are a custom smart material. At a value of 0, just the bone or skin shows. At 1, the skin is covered fully by discolored muscle or frostbite damage. Any value in between gives a spottier look, allowing me to control amount of these damages on the bones and extremities.
Buildup of layers over time
Rigging/Scripting
The rigs are custom made, using my personal modular autorigging toolset. With an initial joint structure, pieces like an arm or a spine can be instantly generated and assembled to get all the basics of a biped rig built to help with skin weight posing or animation tests. Some manual tweaks were necessary on the Winter Shrew. Because the bones are visible on the surface, the scapula and clavicle needed an automatic helper joint to make the scapula rotate around the ribcage naturally. The length of the toes also required three layers of heel roll to be added to get a nicer foot peel for walk cycles.
Control Rig
Blue side has the scapula adjuster turned on, red does not
Three separate channels control the foot peel for animator ease of use
Animation
These cycles are animated in Maya and then implemented in Unreal Engine 5.
Fall Shrew UE5 waddle
Winter Shrew walk cycle (shown in UE5 in the project video)
