Importing HTR/HTR2 Files

Command entry:

Application menu

Import

Motion Analysis HTR File (*.HTR)

The Motion Analysis HTR (Hierarchical Translation-Rotation) file format is a motion-capture format you can import into 3ds Max.

On import, 3ds Max constructs a FK hierarchy rig from the incoming data. The resulting bone skeleton is linked to a dummy object named after the HTR file.

You can import an HTR file directly into the CAT character-animation plug-in. See Importing HTR/BVH Files.

To use an HTR file with a character studio biped, see To use an HTR motion with character studio.

The HTR and HTR2 Formats

The HTR format is an alternative to the BVH format because it provides flexibility in data types and ordering. It also has a complete base pose specification, which consists of indicating the starting point for both rotations and translations. The stored data is grouped by segments; all motions from the first segment are read, then those from the next segment, and so on.

The HTR format contains four sections: Header, Segment Names & Hierarchy, Base Position, and the motion data section.

NoteAll section titles are displayed between square brackets ([]).

NoteComments within the HTR file are denoted by a hash mark (#).

The header section contains global parameter information:

File type
Data type
File version
Number of segments
Number of frames
Data frame rate
Euler rotation order
Calibration units
Rotation units
Global axis of gravity
Bone length axis
Scale factor

HTR2 is nearly identical to HTR, except that the data from the motion section is organized differently in order to better suit a streaming data input (a sample-major ordering is used to present the motion information).

Procedure

To use an HTR motion with character studio:

Note To use an HTR file with a character studio biped, you need to be familiar with using the Map Animation dialog, as well as the naming scheme used for the original motion-captured animation. Once you have created a map (XMM) file, you can use it to map different animations from the source figure onto the same target biped.

the HTR motion into your scene, using the Skeleton Create option.
Once the skeleton in imported, select all its bones and use Animation Save Animation to save the animation as an XAF file.
Create a biped in the scene.
Select all the biped bones and load the previously saved animation onto it using Animation Load Animaton.
3ds Max prompts you to create an XMM file.
In the Map Animation dialog, map all relevant bones from the first skeleton (created from the HTR import process) onto bones in the current biped.
If the original skeleton and the biped have different proportions, you might also need to retarget bones according to their scale. See Retargeting Rollout_TOPIC.
Once the mapping process is done, save your XMM file and then load the XAF motion.

Interface

Skeleton group

Create: Choose this option to build a new bone skeleton from the incoming data. Default=on.
Segment Size: Set this value to modify the scale factor for the weight and height of all bones from the motion capture data. Only available if Create is active.

NoteThis does not change the skeleton's scale.
End Effectors: Toggle this option to import end effectors from the incoming data, if they exist. Only available if Create is active.
Apply: Choose this option to map the incoming data onto the children of the selected skeleton root in your scene.

Keyframe Options group

Base Position: When on, imports only the keys of the base pose.
Animation: When on, imports all animation keys. Default=on.

Rotation Controller group

Euler/TCB: Choose one of the two rotation controllers to apply to the imported data.

Time Options group

These options (except Set Frame Rate) are functional only if the Animation option in the Keyframe Options group is enabled.

All/Range

Choose between using the entire animation range from the motion capture file, or a defined portion of the range.

From/ToThese values represent the start and end frames of the defined range. Available only if Range is active.

Offset

Sets the number of inserted empty frames before the imported animation starts.

NoteThis does not affect the Base Position setting (in the Keyframe Options group), which sets a key at frame 0.

Set Frame Rate

When on, the frame rate from the HTR file overwrites the current one in the Time Configuration dialog.

Scale group

Global: Sets the size of the resulting skeleton.

NoteThe scale value within 3ds Max remains 100.

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OK: Proceeds with HTR/HTR2 import, using the current settings.
Cancel: Cancels HTR/HTR2 import.