Search controls for point cloud mapped fields
The positive and negative normal tolerance values define how far away a source data point can lie from the exterior surface of the target model. The target model surface is interpolated in the undeformed finite element model. By default, each source data point must lie within a distance calculated by multiplying the average element characteristic size in the target model by 0.05. This distance is measured along the positive normal vector of the target surface (see Figure 1).
You can change the tolerance distance values to control which source data points will be included or ignored. You can define the tolerance values as a relative fraction of the average element size in the meshed model or as an absolute distance measured in the length units being used in your model.
For any target points at which Abaqus/CAE cannot map a source point, it will substitute the Default unmapped field value entered in the Create Mapped Field dialog box. The default is zero. The default field value is applied for both point cloud data sources and output database mesh sources.
For a point cloud data source, the following options and search tolerance values are available on the Mapper Controls tabbed page:
- Tolerance type
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If you choose Relative (default), the tolerance values are interpreted as a fraction (not percentage) of the average element characteristic size in the meshed model. If you choose Absolute, the tolerance values are taken as exact distances measured in the length units used in your model.
- Positive normal search distance tolerance
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Any source points within this distance, as measured along the positive normal vector of the underlying geometry of the target surface, are mapped and included in the analysis (see Figure 1). This tolerance applies only to surface (not volumetric) target mapping. The default is 0.05 of the average element characteristic size in the meshed model.
- Negative normal search distance tolerance
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Any source points within this distance, as measured along the negative normal vector of the underlying geometry of the target surface, are mapped and included in the analysis. This tolerance applies only to surface (not volumetric) target mapping. The default is 0.15 of the average element characteristic size in the meshed model.
- Neighborhood search distance tolerance
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Any source data points that lie outside the neighborhood search tolerance are ignored and are not used in the analysis. This tolerance applies to both surface and volumetric target mapping.
Abaqus/CAE uses a distance weighting algorithm to interpolate the field data values on the meshed target model. Abaqus/CAE always tries to interpolate the source values on the target. If Abaqus/CAE finds any points for which interpolation is not possible, a distance weighting algorithm is used that will take nodes within the neighborhood search distance. Distance weighting does not consider any other existing tolerances (positive/negative normal search tolerances or boundary search tolerance). You can deactivate distance weighting by using a very small neighborhood search distance, in which case Abaqus/CAE applies the Default unmapped field value at these nodes.
Abaqus/CAE makes three passes when attempting to map source points onto target points. Abaqus/CAE:
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Tries to interpolate field values on the target. The neighborhood search tolerance is ignored on the first pass.
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Uses the distance weighting algorithm to take source points within the neighborhood search tolerance.
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For any target points that remain unmapped, Abaqus/CAE applies the Default unmapped field value.
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