There are three tools for creation Blast asset.
First one is FractureTool which is used for fracturing input mesh. It supports Voronoi fracturing method and slicing. Internal surface of output chunks can be tesselated and noise can be applied to it. Slicing method supports slicing with noisy slicing surface, which makes possible creation of jagged slicing line. Noisy slicing is switched on by setting non-zero noise amplitude in slicing parameters.
Nv::Blast::FractureTool supports two types of output:
1) Array of triangles - tool fills provided array with triangles of chunk, ID of chunk should be provided.
2) Buffered output - tool fills provided array with vertices, and another array of arrays with indices. Indices form triplets of vertices of triangle.
Nv::Blast::ConvexMeshBuilder is tool for creation collision geometry for physics engine. It recieves mesh vertices, and returns convex hull of that vertices. If creation of convex hull fails, tool creates collision geometry as a bounding box of provided vertices.
Tool provides method to trim convex hulls against each other. It can be used along with noisy slicing to avoid "explosive" behavior due to penetration of neighboor collision hulls into each other. As a drawback penetration of render meshes into each other is possible due to trimmed collision geometry.
Nv::Blast::BlastBondGenerator tool for creation Blast Bond descriptors from provided geometry data. It has separate method which is optimized for working FractureTool.
int32_t Nv::Blast::BlastBondGenerator::buildDescFromInternalFracture(FractureTool* tool, const std::vector<bool>& chunkIsSupport, std::vector<NvBlastBondDesc>& resultBondDescs, std::vector<NvBlastChunkDesc>& resultChunkDescriptors);
Other methods can work with prefractured mesh created in Third party tool, and can be used for converting prefractured models to Blast assets.
Nv::Blast::BlastBondGenerator supports two modes of NvBlastBond data generation:
1) Exact - in this mode exact common surface between chunks is found and considered as interface between them. Exact normal, area and centroid are computed.
2) Average - this mode uses approximations of interface, and can be used for gathering NvBlastBond data for assets, where chunks penetrate each other, e.g. chunks with noise.