magnum.trade.MeshData class

Memory ownership and reference counting

The class can be both owning an non-owning depending on the value of index_data_flags and vertex_data_flags. If they contain neither DataFlags.OWNED nor DataFlags.GLOBAL, the owner property references the object actually owning the index and vertex data the mesh points to. This ensures calling del on the original object will not invalidate the data.

Index and attribute data access

The class makes use of Python’s dynamic nature and provides direct access to index and attribute data in their concrete types via indices and attribute(). The returned views point to the underlying mesh data, element access coverts to a type corresponding to a particular VertexFormat and for performance-oriented access the view implements a buffer protocol with a corresponding type annotation:

>>> mesh = primitives.cube_solid()
>>> list(mesh.indices)[:10]
[0, 1, 2, 0, 2, 3, 4, 5, 6, 4]
>>> list(mesh.attribute(trade.MeshAttribute.POSITION))[:3]
[Vector(-1, -1, 1), Vector(1, -1, 1), Vector(1, 1, 1)]
>>> np.array(mesh.attribute(trade.MeshAttribute.NORMAL), copy=False)[2]
array([0., 0., 1.], dtype=float32)

Depending on the value of index_data_flags / vertex_data_flags it’s also possible to access the data in a mutable way via mutable_indices and mutable_attribute(), for example to perform a static transformation of the mesh before passing it to OpenGL.

Normalized formats (such as VertexFormat.VECTOR3UB_NORMALIZED) are unpacked to a corresponding floating-point representation in element access and packed from a floating-point representation in mutable acess. The type annotation is however still matching the original type (such as '3B' in this case), so code consuming these via the buffer protocol needs to handle the normalization explicitly if needed.

Methods

def attribute(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> corrade.containers.StridedArrayView1D

Data for given named attribute

def attribute(self, id: int) -> corrade.containers.StridedArrayView1D

Data for given attribute

def attribute_array_size(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> int

Array size of a named attribute

def attribute_array_size(self, id: int) -> int

Attribute array size

def attribute_count(self, /) -> int

Attribute array count

def attribute_count(self, name: MeshAttribute, *, morph_target_id: int = -1) -> int

Count of given named attribute

def attribute_count(self, *, morph_target_id: int) -> int

Attribute array count for given morph target

def attribute_format(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> VertexFormat

Format of a named attribute

def attribute_format(self, id: int) -> VertexFormat

Attribute format

def attribute_id(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> int

Absolute ID of a named attribute

def attribute_id(self, id: int) -> int

Attribute ID in a set of attributes of the same name

def attribute_name(self, id: int) -> MeshAttribute

Attribute name

def attribute_offset(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> int

Offset of a named attribute

def attribute_offset(self, id: int) -> int

Attribute offset

def attribute_stride(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> int

Stride of a named attribute

def attribute_stride(self, id: int) -> int

Attribute stride

def has_attribute(self, name: MeshAttribute, *, morph_target_id: int = -1) -> bool

Whether the mesh has given attribute

def mutable_attribute(self, name: MeshAttribute, *, id: int = 0, morph_target_id: int = -1) -> corrade.containers.MutableStridedArrayView1D

Mutable data for given named attribute

def mutable_attribute(self, id: int) -> corrade.containers.MutableStridedArrayView1D

Mutable data for given attribute

Special methods

def __init__(self, primitive: MeshPrimitive, vertex_count: int) -> None

Construct an index-less attribute-less mesh data

Properties

index_count: int get

Index count

index_data: corrade.containers.ArrayView get

Raw index data

index_data_flags: DataFlags get

Index data flags

index_offset: int get

Index offset

index_stride: int get

Index stride

index_type: MeshIndexType get

Index type

indices: corrade.containers.StridedArrayView1D get

Indices

is_indexed: bool get

Whether the mesh is indexed

mutable_index_data: corrade.containers.MutableArrayView get

Mutable raw index data

mutable_indices: corrade.containers.MutableStridedArrayView1D get

Mutable indices

mutable_vertex_data: corrade.containers.MutableArrayView get

Mutable raw vertex data

owner: object get

Memory owner

primitive: MeshPrimitive get

Primitive

vertex_count: int get

Vertex count

vertex_data: corrade.containers.ArrayView get

Raw vertex data

vertex_data_flags: DataFlags get

Vertex data flags

Method documentation

Property documentation