[Sidefx-houdini-list] material IFDs

Nicholas Pliatsikas nick_p102 at hotmail.com
Thu Oct 23 13:09:06 EDT 2008

Hey guys and gals
Righto a few questions about materialIFD workflows.
First off what exactly do materialIFDs store? I was informed that this would allow for sop level material assignment and material overrides to be stored in an external file. To allow us to further proceduralise and modularise the rendering process. This doesn't seem to be the case. Can any one confirm what's going on with material IFDs?
Have geometry cached to disk at an earlier stage in production, before it was shaded for example. Then a shading artists setup a materials assigned at sop level, he has used multiple materials with overrides all over it. Then saves out a materialIFD that can be updated and assigned to the delayed load for that object. Meaning we don't need to update our intial geo Sequence to render this? But this approach doesnt work.
It looks to be that the materialIFDs only use is keep materials outside of the main IFD. Which i guess minimises vop to vex code translations etc and keeps files size down a little ........ It isn't quite as useful as it would first appear.
Also the mantraArchive rop is locked to object level geos when writing our Bgeo Sequences, I don't see why this should be the case? It would be much more usable to be able to specify a sop level node also.
Maybe I'm looking at this wrong.
But in my opinion material IFDs should hold shader information and shader assignment information. 
This would easily give you the abilty to swap out shaders at sop level within takes, use material overrides at sop level on objects with delayed Loads that have been cached to disk already.
A more complex example would be to take a crowd system, it would be great to able to swap out textures, shader assignments etc using material ifds on delayed loads through instancing and using $IPT or instancepoint expression on the materialIFD field. Just an example of how it could be used other then a straight material change across an already cached bgeo sequence.
We have been finding a lot of the material workflows to be pretty production unfriendly and if material Ifds are working like I suspect this really doesn't help the problem involved with them.
Also there isnt any help on the mantra archive node ?
If any one can shed any light on any information in regards to material workflows and materialIfds that would be great.
Nicholas Pliatsikas
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