Hi there, I need to create a shadow pass in Houdini 17.5 and I'm pretty new to the shadow extracting process. After a bunch of trail and error and not being able to locate a good tutorial on the topic, I thought I would ask for help here.
What I am looking for is basically a Mantra version of Arnold's Shadow Matte node. It sounds like the process to get a shadow layer out of Mantra is quite tedious, but I just haven't been able to locate anywhere where it is explained, or at least laid out, how to make one.
I really appreciate all the help you have; I'm counting on you guys!
I have been trying both the shadow matte Mantra shaders (“shading” and “shading utilities”), but I don't know how to output the shadow pass from it.
I have a basic scene setup to show my workflow, please let me know what I am missing in the process. The sphere is going to cast the shadow on the grid.
I applied a standard shader to the sphere, and the shadow matte to the grid.
You need to write out the image plane as an exr, and with the shadow matte shader, you should have white shadows. Then the black part becomes transparent with the exr, and the white becomes your shadows. Then you invert it, and comp it in.