Hi,

Due to the changes with shaders in Houdini 11, I am no longer able to render extra channels using variables like paintExport or diffuseExport, how is this done now in version 11. The doco still mentions these variables but the standard surface shaders don't export these variables any more.

Thanks

Paul

There are new exports found in the Mantra Surface material. When you put down a mantra ROP, you can go to the Properties > Output tab and click on the + sign next to Extra Image Planes. Click on the grey arrow next to VEX Variable and you will see a list of the variables that are available. Some of these are globals such as Alpha, Opacity and Position.

The rest are exported parameters from inside the Mantra surface. You can see there are options for diffuse, specular etc and you can either work with indirect and direct lights separately or combine them. You can also use the per light option to separate out the contributions of different lights. This is an important capability found in the new surface model vop and the Mantra surface material which is harder to do with completely custom shaders.

One thing to note is that there is no separate paint option. It is rendered as part of the diffuse channel. These exports are created when you render therefore no extra time is taken to generate them. You can also use takes to create separate passes for paint and shadows but these will be rendered separately.