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Hi everyone!

I'm a 23 year old student from Norway just started to learn Houdini with the apprentice version.

At my university college we learned how to combine CG-elements with live action plates with Autodesk Maya and Mental Ray's production shaders, IBL with a 360 HDRI, matteshadow and so on.

Then we would render it out as passes and composit it in a compositor like Nuke.

My question is; is there any particular workflow on doing the same in Houdini with Mantra? I understand that Houdini with it nodes is so powerful that I can develop my own workflow. And thats great!

But if anyone in here can show me their typical approach or point me in the direction of some useful information about the subject, that would be great!

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I'll take a crazy stab at it - though I've not done all of this before. If you have to incorporate 3D and live action plates, then I believe that you *have* to do some sort of camera matching. H doesn't have that built in, but a tool like Syntheyes (which is what I have used) does support exporting to Houdini. So if you can match that, then export, then you've got your 3D camera set up.

You can use the Houdini's Take system to create different passes, it's quite easy to use. You could create your geo, create your takes, make a master take for the beauty pass, then a matte take for the matte shadows, etc.

For each take you could create a mantra output node, with the node specifically using a specific type of take. So a mantra out node called "beauty" that uses the beauty take, another called "matte" that uses the matte take, and so on.

For extra pass data, like normals, etc, you can go to the mantra node's output tabs and add a new image plane that exports some specific VEX variable.

Make sure in your mantra settings you're outputting to a file, not the default of "ip", which is the mplay viewer.

Importantly you could connect the mantra nodes together so that one depends on the other, and so on, so that all you need to do is render the bottom-most node and that will in turn kick off renders for all the other dependent nodes as well.

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jim c:

Yeah. I have used Syntheyes for a few projects and its a great tool! Mr. Andersson does a great job!

As you mentioned Syntheyes supports camera exporting to a vast amount of software, Houdini included. So I'm not too worried about that part.

I'm more curious about IBL (Image Based Lighting) with HDR-images; both full 360 degrees stiched spheres, and half spheres (the ones you get from taking a picture of a chrome ball at the set).

Image planes in the background of the viewport, so I have a reference to where to put my CG etc. And how I would catch shadows and reflections like I would with the matteshadow in Mental Ray.

Thank you for the input on Houdinis Take system and passes!

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I'd say if your re familiar with workflows in other packages you won't have much trouble doing the same stuff in houdini. The lightning tools in houdini are great! take a look at PBR rendering along with area and/ore environmentlights. The mantra surface material gives you good flexibility in terms of shading.

http://vimeo.com/6226046

cheers

HT

EDIT: check the shadowmatte material (shop) and the "phantom" ore "matte" option of any geo node...

Edited by hatrick
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