Help. Surface border away from render mesh although already set to smooth display quality

[Tea_Dulton (296197043)]

Hi,

I suspects the surface has some bug, the uv direction should be perpendicular all way around, but it’s not, and the surface display is abnormal.

The file is from my colleague, I don’t know how it happened. I could recreate the surface from curve.

Any suggestions to fix the current surface? Wild guess which surface operation brought in the bug ?

It was an architectural model, the original surface was far away from origin, I have moved it back to around origin.

Thanks. My first post.

debug_01.3dm (69.8 KB)

[wim (Wim Dekeyser)]

Hi and welcome -

@Tea_Dulton

Any suggestions to fix the current surface?

Since the surface is now out-of-context, it’s impossible to tell what the correct fix is.
You can use the Untrim command on the edge and that will create a surface that corresponds with the displayed surface, or you can run DupBorder, explode the resulting curve and use EdgeSrf on these 4 curves. That will give you a surface that corresponds with the visual edges.

@Tea_Dulton

Wild guess which surface operation brought in the bug ?

Possibly a “far-from-origin” trimming issue in Rhino 6. Without having a model in the “pre-bad” state, it’s impossible to know for sure.
-wim

[Normand (Jakob Normand)]

@Tea_Dulton

It was an architectural model, the original surface was far away from origin, I have moved it back to around origin.

You could try RefreshShade to see if it’s just the render mesh (which was probably created far from origin) being messed up.
HTH, Jakob

[Tea_Dulton (296197043)]

@Normand

try RefreshShade to see if it’s just the render mesh

Tried once, not lucky.

@wim

You can use the Untrim command on the edge and that will create a surface that corresponds with the displayed surface

Above quoted method helped.

Good day.

-Tea

[Tea_Dulton (296197043)]

Thanks. Untrim method has brought the face to normal display.

Bonus question,

Then I try to dup edge from the top and bottom;
bring the top curve level up with the bottom;
then extract control polygon from both curves;
“What” display info, indicates the control points of blue curve (from top) and red curve (from bottom) have same xy coordinates.

Should it be the case? As the curves are different from eyeball telling.

Is it a bad (impractical) method to judge 2 curves identical from its control points?

Good day.

[Tea_Dulton (296197043)]

I figured out. The weight of one of the control points is different.