Hi,
I am looking at the docs for houdini 11 …
http://www.sidefx.com/docs/houdini11.0/rendering/deeprasters [sidefx.com]
The section
“set VEX variable to C, Light export to /obj/light1, and Channel name to light1C (or something similar)”
Where is the “Light Export” parameter?
There are just “Export variable for each light” , “Light mask” and “Light Selection” parameters
I am using Houdini 11.0.426
cheers!
Stephen

If you are using one of the new all purpose material - Mantra Surface or one of the other new materials which share its setup then there are built-in light exports. Create an Extra Image Plane in the ROP then click on the arrow next to VEX Variable. the various diffuse, reflect and other passes that correspond to the exports in the material are listed. You can set up the ones you want to use. The “Export variable for each light” will split up the export on a light by light basis and will automatically append the light name to the vex variable name in the final image.

Robert

rmagee
If you are using one of the new all purpose material - Mantra Surface or one of the other new materials which share its setup then there are built-in light exports. Create an Extra Image Plane in the ROP then click on the arrow next to VEX Variable. the various diffuse, reflect and other passes that correspond to the exports in the material are listed. You can set up the ones you want to use. The “Export variable for each light” will split up the export on a light by light basis and will automatically append the light name to the vex variable name in the final image.

Robert

Hi I understand that If I place a parameter VOP in my material surface shader and connect to it something, like the final reflection color, call to the parameter reflct and set it to Export to surface context.
then following your instruction, it should appear in the VEX variable menu, when clicking the arrow button. But only the usual Cf, Of, Af, P, Pz and N appears.
How can I make my exported variables in my materials to appear in the VEX variable options for the Mantra ROP automatically?
Thanks

I don't think it works that way (aka it is that easy)…when you export a variable from VOP/Vex you can render it out to an image plane but you have to type the variable in mantra. It is much like bringing in custom attributes into VOP/Vex but then the other way around

Pagefan
I don't think it works that way (aka it is that easy)…when you export a variable from VOP/Vex you can render it out to an image plane but you have to type the variable in mantra. It is much like bringing in custom attributes into VOP/Vex but then the other way around

Yep I know, is the way I have been doing it so far.
But after reading Robert's email I though there were a new amazing feature in the Mantra ROP to do it automatically.
BTW I think that in the current state of materials implementation it should be farly easy to implement.
the material only needs to test if there are parameters that exports variables to the surface context, then keep an internal list of exported variables/type, this could be done every time the materia lis compiled.
then the Mantra ROP only needs to look at the materials used by the objects in the scene to be rendered and build a list with all the variables exported by the materials.
Another way to implement it that looks much better to me is to have a new VOP operator, for instance called Export Variables, similar to te current output node but with a list that grows with every new connection. For every new connection in the parameters you can set the name of the output variable, the type comes with the connection data type.
This way is more intuitive and is easy to implemented the system I mention before to keep a list of exported variables to integrate it in Mantra and offer to users an easy way to create secundary render passes.
Just my 2 cents

The exports that are found in the Mantra Surface material are shown in that menu. There are already exports ready to go once you assign the material.

If you roll your own then you need to type the variable name yourself.

Robert

rmagee
The exports that are found in the Mantra Surface material are shown in that menu. There are already exports ready to go once you assign the material.
If you roll your own then you need to type the variable name yourself.
Robert

By “exports found in the Mantra surface material”, you mean the outputs for the surface context?
I think would be great to have a exportVOP that could be detected by the Mantra ROP so the image planes menu will be updated automatically.