[Cherry-pick] DYN-10436: Fix UV scaling for degenerate surfaces (sphere poles, cone apex)

[github-actions]

Cherry-pick of #17077 to RC4.1.1_master

Purpose

This addresses the issue reported on slack here.

UvScalingUtilities.GetNormalizedUvScales computed UV aspect-ratio scaling by sampling isolines at the domain boundaries (U/V = 0 and 1) and averaging their lengths. For surfaces with degenerate extrema — sphere poles, cone apex — the isoline at that boundary collapses to a near-zero-length point. Averaging a real length with ~0 badly underestimates the true scale, causing the UV normalization to fall back to normU = 1.0 and breaking the aspect ratio. This in turn causes Delaunay.ByParametersOnSurface and Voronoi.ByParametersOnSurface to produce incorrect tessellations on such surfaces.

Fix: sample isolines at five interior positions (0.1, 0.25, 0.5, 0.75, 0.9) and average their lengths. Interior isolines are non-degenerate for all standard analytical surfaces. For flat/non-degenerate surfaces, all interior isolines have similar length, so the result is unchanged from the previous approach.

Declarations

Check these if you believe they are true

• Is documented according to the standards
• The level of testing this PR includes is appropriate
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.

Release Notes

Fix incorrect UV scaling normalization for surfaces with degenerate boundary isolines (sphere poles, cone apex), restoring correct Delaunay/Voronoi tessellation on those surfaces.

Reviewers

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FYIs

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
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0.0% Coverage on New Code
0.0% Duplication on New Code

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[jasonstratton]

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