Rendering Fine Hair and Fur Using Renderman

Renderman can be used in conjunction with Maya for high quality rendering and animation. Renderman can also work with many other software programs. The software can automatically render Maya fur and hair. These 2 items are very difficult to get right, as each strand of hair will need to be rendered.

Renderman was released by Pixar, and when combined with Maya, is a powerful tool for animation. This plug in is perfect for those individuals that do not need the Renderman preserver or artists tool. The software will take all the scene data from Maya and then render it into the Maya render view window. In this way, the output is movie quality.

Hair and Fur

This hair feature will generate and simulate how bunches of hair will react. It is possible to set the thickness and stiffness of the hair. Hair can be curly, straight or wavy. Fur can be added and it can be painted onto the image. The inclination, curl and length of the fur can be customized. Fur does not have a physical simulation, as it is necessary to run an invisible hair system with the fur for realistic hair movement.

Hair Options

The hair styles can all be customized by changing the length, tip curl, clumping, inclination and polar. There are several presets that can be used for each hairstyle. For a spiked hair cut set a length, clumping factor and zero inclination. For large spikes, the clumping value will be high, for smaller spikes the clumping size will be smaller. The length of the spike is set by the length of the hair. For wet slicked back hair, start with the wet otter preset. Choose which side the hair will be slicked to by setting the inclination and the polar. For a short hair cut, start with the mouse preset and customize the polar, inclination, length and tip curl.

Rendering

Creating the hair and fur in Maya is best, but use Renderman for the rendering. In doing this, the item is created in Maya, but then the deep render mode is used from Renderman for extremely realistic hair. Hair needs to have proper motion blur and be anti-aliased. In particular, Renderman is needed to create realistic hair shadows. Renderman contains a special shadow map. This type of shadow is not always used, but for hair and fur is necessary. This shadow gets rid of the chunky shadows and fine hair shadows. 

Problems

Some of the biggest challenges with hair is simulating the movement and actually getting it to render properly. Maya can generate and simulate the hair, but Renderman is needed for good rendering. Renderman is the best because it renders each individual hair, which is needed for real hair. Many times, fur will be used in the place of short hair. If hair does not need to be detailed, then small clumps of hair can be rendered.

Real hair will clump with static electricity and natural oil. The software algorithms will take this into account when rendering clumps of hair for the most realistic render. Another option for hair in Maya is Joe Alter’s Shave and a Haircut plug in. Use this in Maya and then render with Renderman.