PxCookingParams

Defined in include/cooking/PxCooking.h

struct PxCookingParams

Structure describing parameters affecting mesh cooking.

See also

PxSetCookingParams() PxGetCookingParams()

Public Functions

inline PxCookingParams(const PxTolerancesScale &sc)

Public Members

float areaTestEpsilon

Zero-size area epsilon used in convex hull computation.

If the area of a triangle of the hull is below this value, the triangle will be rejected. This test is done only if PxConvexFlag::eCHECK_ZERO_AREA_TRIANGLES is used.

Default value: 0.06f*PxTolerancesScale.length*PxTolerancesScale.length

See also

PxConvexFlag::eCHECK_ZERO_AREA_TRIANGLES

Range: (0.0f, PX_MAX_F32)

float planeTolerance

Plane tolerance used in convex hull computation.

The value is used during hull construction. When a new point is about to be added to the hull it gets dropped when the point is closer to the hull than the planeTolerance. The planeTolerance is increased according to the hull size.

If 0.0f is set all points are accepted when the convex hull is created. This may lead to edge cases where the new points may be merged into an existing polygon and the polygons plane equation might slightly change therefore. This might lead to failures during polygon merging phase in the hull computation.

It is recommended to use the default value, however if it is required that all points needs to be accepted or huge thin convexes are created, it might be required to lower the default value.

Default value: 0.0007f

Range: <0.0f, PX_MAX_F32)

Note

The plane tolerance is used only within PxConvexMeshCookingType::eQUICKHULL algorithm.

PxConvexMeshCookingType::Enum convexMeshCookingType

Convex hull creation algorithm.

Default value: PxConvexMeshCookingType::eQUICKHULL

See also

PxConvexMeshCookingType

bool suppressTriangleMeshRemapTable

When true, the face remap table is not created.

This saves a significant amount of memory, but the SDK will not be able to provide the remap information for internal mesh triangles returned by collisions, sweeps or raycasts hits.

Default value: false

bool buildTriangleAdjacencies

When true, the triangle adjacency information is created.

You can get the adjacency triangles for a given triangle from getTriangle.

Default value: false

bool buildGPUData

When true, additional information required for GPU-accelerated rigid body simulation is created.

This can increase memory usage and cooking times for convex meshes and triangle meshes.

Default value: false

PxTolerancesScale scale

Tolerance scale is used to check if cooked triangles are not too huge.

This check will help with simulation stability.

See also

PxTolerancesScale

Note

The PxTolerancesScale values have to match the values used when creating a PxPhysics or PxScene instance.

PxMeshPreprocessingFlags meshPreprocessParams

Mesh pre-processing parameters.

Used to control options like whether the mesh cooking performs vertex welding before cooking.

Default value: 0

PxReal meshWeldTolerance

Mesh weld tolerance.

If mesh welding is enabled, this controls the distance at which vertices are welded. If mesh welding is not enabled, this value defines the acceptance distance for mesh validation. Provided no two vertices are within this distance, the mesh is considered to be clean. If not, a warning will be emitted. Having a clean, welded mesh is required to achieve the best possible performance.

The default vertex welding uses a snap-to-grid approach. This approach effectively truncates each vertex to integer values using meshWeldTolerance. Once these snapped vertices are produced, all vertices that snap to a given vertex on the grid are remapped to reference a single vertex. Following this, all triangles’ indices are remapped to reference this subset of clean vertices. It should be noted that the vertices that we do not alter the position of the vertices; the snap-to-grid is only performed to identify nearby vertices.

The mesh validation approach also uses the same snap-to-grid approach to identify nearby vertices. If more than one vertex snaps to a given grid coordinate, we ensure that the distance between the vertices is at least meshWeldTolerance. If this is not the case, a warning is emitted.

Default value: 0.0

PxReal meshAreaMinLimit

“Zero-area” epsilon used in mesh cleaning.

This is similar to areaTestEpsilon, but for the mesh cleaning operation.

If the area of a triangle is below this value, the triangle will be removed. This is only done when mesh cleaning is enabled, i.e. when PxMeshPreprocessingFlag::eDISABLE_CLEAN_MESH is not set.

Default value is 0.0f to be consistent with previous PhysX versions, which only removed triangles whose area was exactly zero.

Default value: 0.0f

See also

PxMeshPreprocessingFlag::eDISABLE_CLEAN_MESH

Range: (0.0f, PX_MAX_F32)

PxReal meshEdgeLengthMaxLimit

Maximum edge length.

If an edge of a triangle is above this value, a warning is sent to the error stream. This is only a check, corresponding triangles are not removed.

This is only done when mesh cleaning is enabled, i.e. when PxMeshPreprocessingFlag::eDISABLE_CLEAN_MESH is not set.

Default value is 500.0f to be consistent with previous PhysX versions. This value is internally multiplied by PxTolerancesScale::length before being used. Use 0.0f to disable the checks.

Default value: 500.0f

See also

PxMeshPreprocessingFlag::eDISABLE_CLEAN_MESH

Range: (0.0f, PX_MAX_F32)

PxMidphaseDesc midphaseDesc

Controls the desired midphase desc structure for triangle meshes.

Default value: PxMeshMidPhase::eBVH34

See also

PxBVH33MidphaseDesc, PxBVH34MidphaseDesc, PxMidphaseDesc

PxU32 gaussMapLimit

Vertex limit beyond which additional acceleration structures are computed for each convex mesh.

Increase that limit to reduce memory usage. Computing the extra structures all the time does not guarantee optimal performance. There is a per-platform break-even point below which the extra structures actually hurt performance.

Default value: 32

PxReal maxWeightRatioInTet

Maximum mass ratio allowed on vertices touched by a single tet.

If a any tetrahedron exceeds the mass ratio, the masses will get smoothed locally until the maximum mass ratio is matched. Value should not be below 1. Smoothing might not fully converge for values <1.5. The smaller the maximum allowed ratio, the better the stability during simulation.

Default value: FLT_MAX