ShrinkTrimmedSrf Issue Maybe?

[Tom_Peterson]

Hi all,

I’m wondering if someone has answer to what I’m seeing with the ShrinkTrimmedSrf command.

When I look at the details of the trimmed surface it makes sense.

Looking at the UV coordinates its telling me where the trimmed surface exists on the overall surface.

But when I run the ShrinkTrimmedSrf command, the UV coordinates do not change.

The overall surface is 64 in wide x 164 in tall so shouldn’t my U be 0 to 164 and my V be 0 to 64?

I’ve uploaded the model for reference.

What am I missing here?

ShrinkTrimmedSrf Issue.3dm (195.0 KB)

What’s really throwing me off is when you evaluate the surface in Grasshopper the plane doesn’t match the UV vectors. If you look at the plane, its telling me the U vector is pointing up and the V vector is pointing left.

But if I display the V vector its pointing up. That doesn’t seem right?

I thought the red line on a plane when evaluating a surface always indicated the U vector and the green line indicates the V vector. Is that not true?

[pascal (Pascal Golay)]

Hello- use Reparameterize > Automatic to make the UV range match, more or less, the 3d size.

-Pascal

[Tom_Peterson]

Got it. Okay so that fixs the UV parameters, but it doesn’t address the evaulate surface issue. It still evaluates the same way. It shows the plane with the U vector pointing up and V vector pointing right, but when I display the V vector of the surface it’s pointing up? Shouldn’t the U and V vectors match the direction of the frame on the surface?

[pascal (Pascal Golay)]

Hi Tom - Faces can have a ‘flipped’ flag to override the UV direction. In a script youi can detect that , I do not know of there is a built-in GH way.

-Pascal

[Tom_Peterson]

Got it. If I use ‘ShowDir’ and swap the UV it fixes the issue I’m seeing in Grasshopper. Thanks for your help!