Computer-aided design - Importing IGES and STEP files

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STEP and IGES files can be directly translated into Medusa's NURBSShape if they only contain NURBS objects. Helper functions, which do that, are provided in the Medusa-Extras repository. For their usage, OpenCASCADE library must be installed on the system.

Some example CAD models are also provided in the repository, code that discretizes a tiger model using the strategy described in Determining the interior of the domain by oversampling the boundary is shown below

 1 NURBSShape<Vec3d, Vec2d> shape = translate_STEP("examples/tiger.step");
 2 double h = 2;
 3 
 4 // Oversample the domain.
 5 DomainDiscretization<Vec3d> oversampled_domain = shape.discretizeBoundaryWithStep(h / 5);
 6 
 7 for (int i = 0; i < oversampled_domain.size(); i++) {
 8     oversampled_domain.normal(i) *= -1;
 9 }
10 
11 // Construct the contains function.
12 KDTree<Vec3d> contains_tree;
13 oversampled_domain.makeDiscreteContainsStructure(contains_tree);
14 auto contains_function = [&] (const Vec3d p) {
15     return oversampled_domain.discreteContains(p, contains_tree);
16 };
17 
18 // Fill the boundary normally.
19 DomainDiscretization<Vec3d> domain = shape.discretizeBoundaryWithStep(h);
20 
21 // Fill the interior with the contains function.
22 KDTreeMutable<Vec3d> tree;
23 GeneralFill<Vec3d> gf;
24 gf(domain, h, tree, contains_function);

Using the provided plot script, we get