blueprints.cache module#

class blueprints.cache.BaseCache[source]#

Bases: UniqueThing, CacheType

Caches are used to store large amounts of data. For blueprints to allow for the modification of this data, it has to be loaded to memory. If this data is part of a Thing which is copied multiple times, this would drastically increase the memory usage for redundant data. Caches solve this, by implementing a single source of data for multiple copies of a Thing. Thing classes that contain large amounts of data can simply outsource them to a cache (by linking the outsourced properties to the caches properties) while keeping small attributes that are modified frequently. To ensure data integrity, if a Things property which is stored in its Cache is modified, a new copy of the caches content is created replacing the old cache attribute of the Thing (unless only one Thing uses the Cache, in which case the Cache is modified directly). For example, consider the following scenario:

Cache example — The large data attribute is outsourced to a Cache#
>>> one = SomeThing(data=open('large.file').read())
>>> one.cache
SomeCache<None:2>
>>> one.data is one.cache.data
True
>>> two = one.copy()
>>> one.cache is two.cache
True
>>> one.name = 'one'
>>> two.name = 'two'
>>> one.cache is two.cache
True
>>> two.data = open('other.file').read()
>>> one.cache is two.cache
False
__init__(**kwargs)[source]#
Parameters:

**kwargs – Keyword arguments are passed to super().__init__.

class blueprints.cache.MeshCache[source]#

Bases: MeshCacheType, BaseCache

This class stores the mesh data which might be loaded from a file and is too large to be copied frequently.

built#

A flag indicating whether the MeshAssets has been built. This is necessary since multiple MeshAssets might use the same MeshCache in which case it should be built only once.

Type:

bool

centered#

If True the vertecies are normalized such that their mean position is the reference frames origin.

Type:

bool

vertecies#

The list of vertecies. Each vertex is a np.ndarray with 3 components for each of the spatial dimensions.

Type:

list

texcoords#

The list of texture coordinates.

Type:

list

texcoords_idx#

A dictionary used to link texture coordinates with face vertecies.

Type:

dict

normals#

The normals used by mujoco, this attribute is derived and should not be used for modification, see face_normals or vertex_normals for this instead.

Type:

list

face_normals#

Face normals are the normal vectors of faces. They specify the direction in which the face points.

Type:

list

vertex_normals#

Vertex normals are the normal vectors of vertecies. They specify the direction in which the vertecies of a face point. Specifying vertex normals instead of face normals enables mujoco to renderer soft edges.

Type:

list

normals_idx#

A dictionary used to link normals with faces.

Type:

TYPE

faces#

This attribute is used to write to xml. It returns a flattened list of indecies that is written raw to xml. For a structured list of faces see faces.

Type:

list

filename#

The user specified file name.

Type:

str

__init__(vertecies=None, faces=None, filename=None, centered=False, **kwargs)[source]#
Parameters:

  • vertecies (np.ndarray | list[np.ndarray | list[float | int]] | None, optional) – A list of all vertex positions.

  • faces (list[np.ndarray | list[float | int]] | None, optional) – A list of all faces. A face consists of at least 3 indecies of vertecies.

  • file (str | None, optional) – The filename from which the mesh data is loaded and to to which the mesh will be saved. The file is saved in a special directory such that no input file is overwritten by the output file.

  • centered (bool, optional) – If True the vertecies are normalized such that their mean position is the reference frames origin.

  • **kwargs – Keyword arguments are passed to super().__init__.

  • filename (str | None)

Return type:

None

copy(**kwargs)[source]#

This method constructs a copy of the Cache with possible alterations to its attributes as specified in kwargs.

Parameters:

**kwargs – Keyword arguments are passed to the __init__() to replace the attributes of the current Thing from which copy is called.

Returns:

A new instance of the Cache

Return type:

blue.CacheType

load(filename)[source]#

This methods loads the mesh data from a file.

Parameters:

filename (str) – Possible file types are '.stl' binary or ascii and '.obj' ascii.

Return type:

None

save(file)[source]#

This method saves the Mesh data to a file.

Parameters:

file (str) – The name to which the file is saved.

Raises:

NotImplemented – If the file format is not supported an error is raised.

Return type:

None

property file: str | None#

Filename for Mujoco XML

Return type:

str

property vertex#
returns: This attribute is used to write construct the mujoco xml. It returns a flattened list of

coordinates that is written raw to xml. For a structured list of vertecies see vertecies.

Return type:

np.ndarray

property face: ndarray | None#
returns: This attribute is used to write construct the mujoco xml. It returns a flattened list of

coordinates that is written raw to xml. For a structured list of faces see faces.

Return type:

np.ndarray | None

property texcoord: ndarray | None#
returns: This attribute is used to write to xml. It returns a flattened list of texture coordinates that

is written raw to xml. For a structured list of texture coordinates see texcoords.

Return type:

np.ndarray | None

property normal: ndarray | None#
returns: This attribute is used to write to xml. It returns a flattened list of face normals that

is written raw to xml. For a structured list of face normals see normals.

Return type:

np.ndarray | None

property size: ndarray#
returns: The size of the Mesh is computed as the difference of the minimal and maximal component

for each axis on each vertex.

Return type:

np.ndarray

property vertecies: ndarray#
returns: The list of vertecies. Each vertex is a np.ndarray with 3 components for each of the

spatial dimensions.

Return type:

np.ndarray

property faces: list[ndarray] | None#
returns: The list of faces. Each face is a np.ndarray with n indecies for each of the vertecies

of the face.

Return type:

list[np.ndarray] | None

property texcoords: list[ndarray] | None#
returns: The list of texture coordinates. Each texture coordinate is a np.ndarray with

coordinates in the range [0, 1] specifying the point on the texture which is mapped to the referencing face vertex.

Return type:

list[np.ndarray] | None

property texcoords_idx: dict | None#

returns: The list of texture coordinate indecies for faces. :rtype: dict | None

property face_normals: list[ndarray] | None#
returns: Face normals are the normal vectors of faces. They specify the direction in which the

face points.

Return type:

list[np.ndarray] | None

property vertex_normals: list[ndarray] | None#
returns: Vertex normals are the normal vectors of vertecies. They specify the direction in which

the vertecies of a face point. Specifying vertex normals instead of face normals enables mujoco torenderer soft edges.

Return type:

list[np.ndarray] | None

property normals_idx: dict | None#

The list of normals indecies for faces.

Return type:

dict | None

property vertecies_min#

The minimum for each axis component of all vertecies.

Return type:

np.ndarray

property vertecies_max#

The maximum for each axis component of all vertecies.

Return type:

np.ndarray

property vertecies_center#

The middle point for each axis component of all vertecies.

Return type:

np.ndarray

class blueprints.cache.HFieldCache[source]#

Bases: HFieldCacheType, BaseCache

__init__(terrain=None, filename=None, **kwargs)[source]#
Parameters:

  • terrain (ndarray | list[ndarray | list[float | int]] | None)

  • filename (str | None)

copy(**kwargs)[source]#

This method constructs a copy of the Cache with possible alterations to its attributes as specified in kwargs.

Parameters:

**kwargs – Keyword arguments are passed to the __init__() to replace the attributes of the current Thing from which copy is called.

Returns:

A new instance of the Cache

Return type:

blue.CacheType

load(filename)[source]#

This methods loads the mesh data from a file.

Parameters:

filename (str) – Possible file types are '.stl' binary or ascii and '.obj' ascii.

Return type:

None

save(filename)[source]#

This method saves the Mesh data to a file.

Parameters:

  • file (str) – The name to which the file is saved.

  • filename (str)

Raises:

NotImplemented – If the file format is not supported an error is raised.

Return type:

None

property elevation#

Derived dummy property

property nrow: int#

Number of rows in the terrain.

Return type:

int

property ncol: int#

Number of collumns in the terrain.

Return type:

int

property filename: str#

The filename of the hfield data.

Return type:

str

property terrain: ndarray#
returns: The list of vertecies. Each vertex is a np.ndarray with 3 components for each of the

spatial dimensions.

Return type:

np.ndarray

property file: str#

Dummy variable for the default names of hfield data files.

Return type:

str