BMTR format (binarized RTM)¶

The armaio.rtm module provides utilites for reading the binarized RTM animation format. The implementations are based on the Community Wiki binarized RTM page and further research.

For “binarized” RTM files, the module only supports reading. Writing is only supported through conversion to the “plain” representation.

Warning

While both the “plain” and “binarized” RTM formats use the .rtm extension, the actual file format is completely different, and not interchangeable.

In contrast to “plain” files, the BMTR format uses optional compression in some data blocks, and the transformation data itself is stored as relative quaternion-vector pairs, instead of absolute matrices.

Examples¶

Reading¶

from armaio.rtm import BmtrFile

bmtr = BmtrFile.read_file("animation_binarized.rtm")
print(bmtr.motion)

Converting¶

from armaio.rtm import RtmFile, BmtrFile, BoneStructure

bmtr = BmtrFile.read_file("animation_binarized.rtm")
skeleton: BoneStructure = {
    "pelvis": {
        "torso": {
            "leftarm": {},
            "rightarm": {}
        }
    }
}

rtm = RtmFile.from_binarized(bmtr, skeleton)
print(rtm.motion)

Exceptions¶

class armaio.rtm.BmtrError¶: Exception raised upon BMTR reading errors.

Classes¶

class armaio.rtm.BmtrFrame(phase: float, bones: tuple[str, ...])¶

Animation frame at a given phase, containing the transformation data for all bones.

Parameters:

phase (float) – Animation phase
bones (tuple[str, ...]) – Bones animated in the frame

Raises:

BmtrError – Duplicate bones

classmethod read(stream: IO[bytes], phase: float, bones: tuple[str, ...]) → Self¶

Reads an animation frame from a binary stream.

Parameters:

stream (IO[bytes]) – Source binary stream
phase (float) – Animation phase
bones (tuple[str, ...]) – List of expected bones

Returns:

Animation frame

Return type:

Self

property phase: float¶

Returns:: Animation phase
Return type:: float

property transforms: MappingProxyType¶

Returns:: Bone transformations
Return type:: MappingProxyType[str, tuple[RtmQuaternion, RtmVector] | None]

class armaio.rtm.BmtrFile¶

Animation data read from a binarized RTM file.

classmethod read(stream: IO[bytes]) → Self¶

Reads binarized animation data from a binary stream.

Parameters:: stream (IO[bytes]) – Source binary stream
Raises:: BmtrError – Stream is not valid animation data
Returns:: Animation data
Return type:: Self

classmethod read_file(filepath: str) → Self¶

Reads animation data from a binarized RTM file at a given path.

Parameters:: filepath (str) – Path to RTM file
Returns:: Animation data
Return type:: Self

property bones: tuple[str, ...]¶

Returns:: Bones in the animation
Return type:: tuple[str, …]

property frames: tuple[BmtrFrame, ...]¶

Returns:: Animation frames
Return type:: tuple[RtmFrame, …]

property motion: RtmVector¶

Returns:: Motion vector
Return type:: RtmVector

property properties: tuple[RtmProperty, ...]¶

Returns:: Phase-linked animation properties
Return type:: tuple[tuple[float, str, str], …]

property source: str | None¶

Returns:: Path to source file (None if not read from file)
Return type:: str | None

property version: int¶

Returns:: Format version
Return type:: int