Forums Houdini Indie and Apprentice Decals orientation to follow AO direction

Decals orientation to follow AO direction

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Haruko
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Hello, I hope someone can help me with this.
I am creating decals with a scatter node based on a density attribute created using a Mask by feature (AO).
The fact is that I would like these decals to have the correct orientation based on the propragation of the AO as seen in the attached image.
I don't know if I could add some attribute to these points that read that direction or be able to detect the edges of the geometry to see where I have to rotate/orient my decals.

Thank you

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AO_Direction.png (448.6 KB)

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CYTE
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You can use the polyframe node for that. It can compute a vector from a gradient.

Cheers
CYTE
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Haruko
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Good advice to start working with.

Unfortunately it tells me that the attribute is invalid even though it is a point attribute with descending numbers as can be seen in the spreadsheet.

Any advice?
Thx.

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polyframe.PNG (340.0 KB)

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CYTE
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you need to convert your density to a vector first.
use a wrangle like this : 
v@gradient = set(@density,0,0);

Cheers
CYTE
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Haruko
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It worked!

Thank you so much.
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tamte
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You can also use Measure SOP to get vector gradient direction of a float attribute
Tomas Slancik
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Haruko
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Thank you for the adding some possibilites @tamte.

But the fact is I get cleaner results with the awrangle conversion rather than with the measure SOP. As you can see in the images below, the vectors are better aligned with the AO gradient with the conversion method. Maybe it's a matter of tweaking the measure SOP.
But again, thank you.




Edited by Haruko - 2023年6月29日 02:44:33

Attachments:
Measure.PNG (182.6 KB)
Awrangle conversion.PNG (159.5 KB)

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