A3DRWParamsTessellationData

Fields

A3DETessellationLevelOfDetail	m_eTessellationLevelOfDetail
A3DDouble	m_dChordHeightRatio
A3DDouble	m_dAngleToleranceDeg
A3DDouble	m_dMinimalTriangleAngleDeg
A3DDouble	m_dMaxChordHeight
A3DBool	m_bAccurateTessellation
A3DBool	m_bAccurateTessellationWithGrid
A3DDouble	m_dAccurateTessellationWithGridMaximumStitchLength
A3DBool	m_bAccurateSurfaceCurvatures
A3DBool	m_bDoNotComputeNormalsInAccurateTessellation
A3DBool	m_bKeepUVPoints
A3DBool	m_bUseHeightInsteadOfRatio
A3DDouble	m_dMaximalTriangleEdgeLength

Detailed Description

struct A3DRWParamsTessellationData

Structure to set the tessellation parameters.

Version

3.0

Public Members

A3DETessellationLevelOfDetail m_eTessellationLevelOfDetail

Enum to specify predefined values for some following members.

A3DDouble m_dChordHeightRatio

Specifies the ratio of the diagonal length of the bounding box to the chord height. A value of 50 means that the diagonal of the bounding box is 50 times greater than the chord height. Values can range from 50 to 10,000. Higher values will generate more accurate tessellation.

A3DDouble m_dAngleToleranceDeg

Specifies the maximum angle between two contiguous tessellation segments describing the curve of a topological edge for every face.

During tessellation, the curve describing the edge of a topological face will be approximated using straight line segments. m_dAngleToleranceDeg is the maximum angle between two consecutive segments.

Allowable values range from 10 to 40. Lower values will result in greater accuracy.

A3DDouble m_dMinimalTriangleAngleDeg

Specifies the angle between two contiguous segments of wire edges for every face. Allowable values range from 10 through 30.

Deprecated:

This is a deprecated feature, which will be removed in version 2026.1.0.

A3DDouble m_dMaxChordHeight

Specifies the maximum distance between the original geometric surface specified in the CAD file and the resulting tessellation. Be careful, very small values can generate very large tessellation files.

Conversely, very large values can generate inaccurate tessellation. In such cases, it may be better to use the

m_dChordHeightRatio member to scale this value relative to the object that’s being tessellated.

Note

m_dMaxChordHeight is ignored if m_bUseHeightInsteadOfRatio isn’t set to true.

A3DBool m_bAccurateTessellation

Accurate tessellation. Uses standard parameters. ‘A3D_FALSE’ indicates the tessellation is set for visualization. Setting this value to ‘A3D_TRUE’ will generate tessellation more suited for analysis. Can be used with all TessellationLevelOfDetails.

A3DBool m_bAccurateTessellationWithGrid

Enable accurate tessellation with faces inner points on a grid.

A3DDouble m_dAccurateTessellationWithGridMaximumStitchLength

Maximal grid stitch length. Disabled if value is 0. Be careful, a too small value can generate a huge tessellation.

A3DBool m_bAccurateSurfaceCurvatures

Take into account surfaces curvature in accurate tessellation to controle triangles elongation directions. Enable m_bAccurateTessellation or m_bAccurateTessellationWithGrid to use this option.

A3DBool m_bDoNotComputeNormalsInAccurateTessellation

Do not compute surface normals in accurate tessellation. Enable m_bAccurateTessellation or m_bAccurateTessellationWithGrid to use this option.

A3DBool m_bKeepUVPoints

Keep parametric points as texture points.

A3DBool m_bUseHeightInsteadOfRatio

Use m_dMaxChordHeight instead of m_dChordHeightRatio if m_eTessellationLevelOfDetail = kA3DTessLODUserDefined.

A3DDouble m_dMaximalTriangleEdgeLength

Maximal length of the edges of triangles. Disabled if value is 0. Be careful, a too small value can generate a huge tessellation.