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HtoA + Chaining Set Parameter

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Message 1 of 5
Andrew_Wilkins1
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HtoA + Chaining Set Parameter

Hello,

I'm trying to use "Collections & Set Parameter" operators to chain together—but it doesn't seem to work for me.
Using collections to filter for the entire set and some FG assets.

I've tested the collections and set parameter expressions, independently everything works fine.

Example:

phantom-01.jpg


I would expect:

  1. "visibility=254" on #set to evaluate first and then
  2. visibility=255 on the #fg_rock
  3. Finally the set has "Camera Visibility" disabled and the FG asset has it enabled again after, so we should see the fg asset rendering.


But this isn't working?

I tried a Merge operator, straight into the ROP, re-ordering the inputs and tried as a separate stream.

I also tried on the "Set Parameter" selection expression as:
#set and not #fg_rock

phantom-02.jpg

Like the Doc example:

https://docs.arnoldrenderer.com/display/A5AFHUG/Collection

# Here we create a smaller collection using an exclusion set
collection
{
  selection "#custom_collection and not #exclude_selection"
  collection "smaller_collection"
}



Any ideas why this isn't behaving as I'm expecting?


All the best,
Andrew


Houdini: 18.5.462
HtoA: 5.6.0.0
Arnold:
6.2.0.0

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4 REPLIES 4
Message 2 of 5

Hey,

Just bumping this and offering more info—really hoping to incorporate this in HtoA.

This is how it would work in Maya (works perfectly), can be super useful.

ie. modify entire set attributes and then reverse that on a collection of assets.

chaining-overrides.jpg


Regards,
Andrew

Message 3 of 5

Hi again,

This may be due to me testing with "HtoA: 5.6.0.0" arnold procedurals—I tested with a default Houdini sphere and that worked fine using something like:
(on the "Set Parameter" node)

#set not #sphere


I'm going to test on a newer HtoA version and see if it's still not working there.

Message 4 of 5

Hi,

Updated to HtoA: 5.6.3.0 - results of Arnold Operators still not working as expected.

As a quick example, here's some more info.

Collections:

#set 
expression: *Set_*

#fg_rock 
expression: *Set_Rock_A_Proc_11*


#fg_rock
Set Parameter: matte = True

Working as expected

matte-fg-01.jpg

#set
Set Parameter: matte = True

Working as expected

matte-set-01.jpg


#set not #fg_rock
Set Parameter: matte = True

Not working as expected. Everything is matted?
I'm expecting the set to be matted and the fg rock unmatted.

set-not-rock.jpg

#set and not #fg_rock
Set Parameter: matte = True

Not working as expected.
I'm expecting the set to be matted and the fg rock unmatted.

set-and-not-rock.jpg


2x chained set parameter

set_parameter 1: 
#set 
matte = True

set_parameter 2: 
#fg_rock
matte = False

Not working as expected.
I'm expecting the set to be matted and the fg rock unmatted.

chained-set-parameter.jpg


Any ideas why this isn't working? Possibly specifically with Arnold Procs?

It's making it impossible to build an Arnold workflow for render passes around Arnold Operators.


Regards,
Andrew


Houdini: 18.5.596
HtoA: 5.6.3.0
Arnold:
6.2.1.1

Message 5 of 5

Hi again,


For those following—the issues lies with the arnold procedurals & auto-instancing.

  • If I disable "auto-instancing" on the procedural rock asset I'm trying to modify with operators, it works.
  • If I do the same steps manually on all the individual assets—I don't need to disable "auto-instancing" and everything still works as I'm expecting.


This seems to be an issue with using Arnold Operators on "auto-instanced" procedurals.
Would be great to have this one fixed.


All the best,
Andrew

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