User manual

© Next Limit Technologies 2010
Maxwell Render 2.5 User Manual
Chapter 10. Maxwell Materials | 80
Appropriate base mesh geometry
Objects made of evenly distributed polygons are preferable because they provide better
quality. You should avoid base geometry with disproportionate triangles that converge to
the same point. In areas with many small, converging triangles you may get artifacts when
using displacement.
Rendering sharp details
To render sharp details, consider turning off texture ltering. It will help you render sharper
high-contrast areas in your texture. If you are using a moderate gain value, displacement
will slightly smooth the rendered detail. In this case you should turn off Smoothing under
the displacement options to render the details sharper. Keep in mind that turning off
texture interpolation might reveal a stair-stepping effect if using 8-bit maps with smooth
gradients.
Object Smoothing Angle
To avoid any possible artifacts/ gaps in the displacement on objects which contain polygons
connected at sharp angles, make sure you set an object smoothing angle that exceeds the
maximum polygon angle of the object (i.e. for a cube, it should be 90 or greater).
10.07 Special features
The “Matte” and “Shadow” options can be found in the Material Properties of the Material
Editor.
10.07.01 Matte material
This option turns the material into a matte material which “cuts” through the entire image
and reveals the background; physical sky if enabled; black if no environment lighting is
used. This is useful for compositing purposes. For example, if you have columns in front
of a character and the columns will be rendered in another pass, you can turn on matte
material for the columns, and the character will be rendered with the columns “cut” from
the character. The columns will still contribute to the lighting, even with Matte material
turned on.
10.07.02 Shadow Channel
This option can be turned on for a material and will make all objects with that material
applied behave as shadow catchers. If you turn on shadow channel in the Render Options
panel, all materials that have this option turned on will only render shadows. All materials
with this option turned off will render white. This allows you to render a shadow-only pass
for compositing purposes. Keep in mind that the shadow pass progressively increases
in quality, just like the main render. If you have both the main render channel and the
shadow pass channel checked in render options, two separate images will be rendered,
one being the main render, the other the shadow pass.
The following image demonstrates the procedure to export different channels from
Maxwell and the nal image after compositing:
1. The background image
2. The ground render
3. The ground alpha
4. The car and ground alpha
5. Objects ID channel
6. Material ID channel
7. Ground shadows
8. Car shadows
9. Roughness channel
10. Fresnel channel
11. Diffuse passs
12. Reections Pass
13. Z-buffer channel
14. The nal composition