raisim::Mesh

final class · #include <raisim/object/singleBodies/Mesh.hpp>

Inherits: raisim::SingleBodyObject

A rigid body defined by a triangle mesh (create it with World::addMesh()). By default the collision geometry is the convex hull of the mesh; it can also be the original triangle mesh or a CoACD convex decomposition. Vertices are stored scaled, in the body frame.

Nested classes

• struct ConvexPart — One convex part of a CoACD decomposition, in the body frame.
• class FileCache — Mesh files read by World::addMesh(), so a mesh placed many times (a .rasset collider, say) is read from disk once per world.
• struct PreprocessOptions — Options for preprocessMesh().
• struct PreprocessResult — Result of preprocessMesh().

Constructors & destructor

Mesh

explicit Mesh(
    const std::string &filename,
    double mass,
    const Mat<3, 3> &inertia,
    const Vec<3> &COM,
    double scale,
    const CoacdOptions &coacdOptions)

Load a mesh with user-given mass properties and use a CoACD convex decomposition for collision (falls back to the convex hull with a warning if the decomposition fails).

Parameters

Parameter	Description
filename (in)	mesh file (OBJ, USD, or any format supported by Assimp)
mass (in)	mass (kg)
inertia (in)	inertia about the COM in the body frame (kg m^2)
COM (in)	center of mass in the body frame (m, after scaling)
scale (in)	uniform scale applied to the vertices
coacdOptions (in)	decomposition parameters

explicit Mesh(const std::string &filename, double mass, double scale=1.0)

Load a mesh and use its convex hull for collision. The COM is the center of the vertex bounding box and the inertia is that of a uniform box with the bounding box dimensions.

Parameters

Parameter	Description
filename (in)	mesh file (OBJ, USD, or any format supported by Assimp)
mass (in)	mass (kg)
scale (in)	uniform scale applied to the vertices

explicit Mesh(
    const std::string &filename,
    double mass,
    double scale,
    const CoacdOptions &coacdOptions)

Same as Mesh(const std::string&, double, double) but uses a CoACD convex decomposition for collision.

Parameters

Parameter	Description
filename (in)	mesh file
mass (in)	mass (kg)
scale (in)	uniform scale applied to the vertices
coacdOptions (in)	decomposition parameters

~Mesh

~Mesh() final

Public member functions

getMeshFileName

const std::string &getMeshFileName() const

Returns mesh file name if it was created with a file. Otherwise, returns an empty string

getVerticies

const std::vector<float> &getVerticies() const

Returns the scaled vertices as a flat xyz array in the body frame.

getIndicies

const std::vector<std::uint32_t> &getIndicies() const

Returns the triangle index buffer (three indices per triangle).

getScale

double getScale() const

Returns the uniform scale applied to the vertices.

isConvexified

bool isConvexified() const

Returns true unless the original (possibly concave) triangle mesh is used for collision, i.e., true for both convex hull and CoACD.

getCoacdOptions

const CoacdOptions &getCoacdOptions() const

Returns the CoACD options given at construction.

getCoacdConvexParts

const std::vector<ConvexPart> &getCoacdConvexParts() const

Returns the CoACD convex parts; empty unless a decomposition is in use.

getCollisionBodyCount

size_t getCollisionBodyCount() const

Returns the number of collision bodies (1, or the number of convex parts for CoACD).

getCollisionBodyAt

CollisionBodyHandlePtr getCollisionBodyAt(size_t index)

Parameters

Parameter	Description
index (in)	collision body index, less than getCollisionBodyCount()

Returns the collision body (owned by the mesh), or nullptr if out of range

CollisionBodyHandleConstPtr getCollisionBodyAt(size_t index) const

Parameters

Parameter	Description
index (in)	collision body index, less than getCollisionBodyCount()

Returns the collision body (owned by the mesh), or nullptr if out of range

setBodyType

void setBodyType(BodyType type) override

Same as SingleBodyObject::setBodyType(), applied to all collision bodies.

Parameters

Parameter	Description
type (in)	the body type

updateContactAabbs

void updateContactAabbs() override

Internal: recomputes the world-frame AABBs used by the broadphase.

updateCollision

void updateCollision() override

Internal: synchronizes the collision geometry with the current pose.

Static member functions

loadMesh static

static void loadMesh(
    const std::string &filename,
    std::vector<float> &verticies,
    std::vector<std::uint32_t> &idx,
    double scale=1)

Load a triangle mesh. OBJ and USD files use built-in loaders; other formats use Assimp. Fatal error on failure.

Parameters

Parameter	Description
filename (in)	mesh file
verticies (out)	flat xyz vertex buffer
idx (out)	triangle index buffer
scale (in)	uniform scale applied to the vertices

loadObj static

static void loadObj(
    const std::string &filename,
    std::vector<float> &verticies,
    std::vector<std::uint32_t> &idx,
    double scale=1)

Load an OBJ file (the extension must be .obj). Fatal error on failure.

Parameters

Parameter	Description
filename (in)	OBJ file
verticies (out)	flat xyz vertex buffer
idx (out)	triangle index buffer
scale (in)	uniform scale applied to the vertices

writeObj static

static void writeObj(
    const std::string &filename,
    const std::vector<float> &vertices,
    const std::vector<std::uint32_t> &idx)

Writes a triangle mesh as a normalized OBJ file. Missing parent directories are created.

Parameters

Parameter	Description
filename (in)	output path
vertices (in)	flat xyz vertex buffer (size must be a multiple of 3)
idx (in)	triangle index buffer (size must be a multiple of 3)

computeFileHash static

static std::uint64_t computeFileHash(const std::string &filename)

Computes a deterministic content hash for an asset file.

Parameters

Parameter	Description
filename (in)	file to hash (fatal error if it cannot be opened)

Returns 64-bit content hash

preprocessMesh static

static PreprocessResult preprocessMesh(
    const std::string &filename,
    const PreprocessOptions &options)

Loads any supported mesh format and writes a normalized triangulated OBJ cache. The cache filename includes the source content hash and the scale so stale cached assets are not reused after source or scale changes.

Parameters

Parameter	Description
filename (in)	source mesh (any format supported by loadMesh())
options (in)	scale, cache directory and force flag

Returns paths, hash and size of the processed mesh

Inherited members

From raisim::SingleBodyObject: clearExternalForcesAndTorques, getAngularVelocity, getAppearance, getBodyToComPosition_rs, getCollisionBody, getCollisionGroup, getCollisionMask, getCom, getComPosition, getComPosition_rs, getContactPointVel, getDOF, getEnergy, getGeneralizedCoordinateDim, getGyroscopicMode, getInertiaMatrix_B, getInertiaMatrix_B_rs, getInertiaMatrix_W, getInertiaMatrix_W_rs, getKineticEnergy, getLinearMomentum, getLinearVelocity, getMass, getObjectType, getOrientation, getPosition, getPotentialEnergy, getQuaternion, getRotationMatrix, getVelocity, integrate, preContactSolverUpdate1, preContactSolverUpdate2, setAngularDamping, setAngularVelocity, setAppearance, setCom, setConstraintForce, setExternalForce, setExternalTorque, setGyroscopicMode, setInertia, setLinearDamping, setLinearVelocity, setMass, setOrientation, setPose, setPosition, setVelocity

From raisim::Object: addContactToPerObjectContact, clearPerObjectContact, getBodyType, getContactAabb, getContactAabbCount, getContacts, getExternalForce, getExternalForcePosition, getExternalTorque, getExternalTorquePosition, getId, getIndexInWorld, getName, getRenderRevision, Id, lock, lockMutex, setIndexInWorld, setName, try_lock, unlock, unlockMutex