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cwalrus

VDB SDF WTF

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Hi - 

 

Could someone explain what VDB and SDF are, in plain english? I thought they were different types of volumes, but I see odd terminology in the help file that seems to combine them:

 

dop_example_keyframedgrains from the docs

 

thanks

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VDB is a sparse voxel storage format. An SDF is a scalarfield (of distances to a surface) which can by stored within the VDB format, or within the dense voxel format in Houdini simply called "Volumes".

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I thought they were different types of volumes

Fog and SDF are different types of volumes. VDB is a new fast implementation of them, I think it intended to supersede standard Houdini's Volumes, tending to re-create its nodes, although it seems, that it will be subset of them, with some unique features in both implementations.

Edited by f1480187

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Yep.

 

Whenever I learn a thing, I have to write it down, otherwise it's gone within a week. :)

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This is very well-written and informative notebook.

The fact it is maintained by one man is... impressive.

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But VDB, SDF are acronyms for exactly....what? 

Houdini is an acronym lovers utopia it seems:)

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From OpenVDB.org 

Quote

Over the years VDB has been interpreted to mean different things, none of which are very descriptive: "Voxel Data Base", "Volumetric Data Blocks", "Volumetric Dynamic B+tree", etc. In early presentations of VDB we even used a different name, "DB+Grid", which was abandoned to emphasize its distinction from similarly named, but different, existing sparse data structures like DT-Grid or DB-Grid. The simple truth is that "VDB" is just a name. :-)

SDF stands for "Signed Distance Field".

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5 hours ago, eco_bach said:

But VDB, SDF are acronyms for exactly....what? 

Houdini is an acronym lovers utopia it seems:)

VDB is actually a third party lib from Dreamworks. I guess they love their acronyms too :)

Volume: Dynamic Blocked is what I believe it stands for.

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