OBD:TRTA

ONI BINARY DATA TRSC << Other file types >> TSFF TRTA : Totoro Quaternion Body Translation Array switch to XML:TRTA page Overview @ Oni Stuff

Offset	Type	Raw Hex	Value	Description
0x00	res_id	01 62 04 00	1122	01122-.TRTA
0x04	lev_id	01 00 00 06	3	level 3
0x08	char[22]	AD DE...	dead	unused
0x1E	int16	13 00	19	array size
First bone offset (black outline)
0x00	float	00 00 00 00	0	x-offset of bone (pelvis) with respect to parent
0x04	float	00 00 00 00	0	y-offset of bone (pelvis) with respect to parent
0x08	float	00 00 00 00	0	z-offset of bone (pelvis) with respect to parent

Skeleton

The hierarchy of the bones (parents, children, siblings) is defined in the TRIA file (linked to from the same TRCM file as the TRTA).

If the (0°, 0°, 0°) orientation is set for every bone, then all the bones point along the X axis of the character (from right to left) and face upwards.

Viewed from above, you get something like this : "o" is a pivot (yes, the shoulders are attached to the neck), and ":)" is a smiley :)

14-o-13-o-12-o-11-o 3-o-2-o-1-o       ^ z
                  |           |       ^
           :)10-o-9-o-8-o-7-o-0  < < <^< < <
                  |           |   x   ^
18-o-17-o-16-o-15-o 6-o-5-o-4-o       ^

XYZ offsets

The XYZ-offsets in the TRTA are offsets (aka "translations") of a bone relative to its parent in that system of coordinates (see above).

Thus they effectively specify the relative positions of the joints.

The different TRTA occurring in Oni are detailed HERE.

Pelvis

Pelvis is further translated with respect to the root bone by the height track of TRAM

The root bone is translated by TRAM as well as by the physics engine (jumps, blasts).

Relevant offsets

You may notice that X and Y offset for thighs and shoulders is very small (it's the left/right i.e. Z that matters there).

For all the other bones, the offset is essentially along X (i.e. along the main axis of the bone meshes). Y and Z offsets are very small.

So X/Y offsets of shoulders and thighs can basically be set to zero, as well as Y/Z offsets of all the other bones.

A skeleton is primarily defined by the Z offsets of shoulders and thighs (broad/narrow shoulders and hips), and by the X offset (effectively, the length) of all the other bones.

ONI BINARY DATA
TRSC << Other file types >> TSFF
TRTA : Totoro Quaternion Body Translation Array
Character file