OBD:CRSA: Difference between revisions

OBD:CRSA (view source)

Revision as of 17:55, 27 December 2006

240 bytes removed , 27 December 2006

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→‎Corpses: matrix

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 *A space for notes (160 bytes) : often the name of the file the corpse was taken from when packing the array.
 *A link to the [[OBD:ONCC|ONCC]] (model that should be used for the corpse) : that's 4 bytes as usual.
-*Then, 19 bones, each of them defined by absolute orientation and position (unlike in a [[OBD:TRAM/raw0x34|TRAM]], where orientations are relative)<br>Every bone is (3*3 + 3)*4 = 48 bytes, so that's 19*48 = 912 bytes.
+*Then, 19 bones, each of them defined by absolute position and transformation matrix<br>Every bone is (3*3 + 3)*4 = 48 bytes, so that's 19*48 = 912 bytes.
 *Finally, an axis-aligned bounding box (2*3*4 = 24 bytes)
 The total size of a corpse is thus 1100 bytes.
-;What's in a bone?:The absolute orientation is defined in a "heavy" way ''via'' an orthonormal trihedron :
+;What's in a bone?
-:three 3D vectors '''x''', '''y''' and '''z''', each of length 1, at right angles with each other, and ordered "directly"
+:The transformation matrix and the offset.
-:(like Oni's world axes : if '''x''' points left and '''y''' points up then '''z''' points to ''front'', not back).
-:Each one of those vectors is stored as 3 floats (3*4 bytes), first '''x''', then '''y''', then '''z''' (so 3*3*4 = 36 bytes in total).
+:The transformation matrix can define rotation, stretching, mirroring etc, in the following way.
-:The absolute position '''R''' of a bone (of its parent node, actually) is stored as 3 floats right after the orientation trihedron.
+:It can be seen as three 3D vectors '''x''', '''y''' and '''z''' (see table below).
-:That's another 12 bytes, so 48 bytes in total.
-Reminder : the 2nd coordinate of '''R''' aka ''y'' is the height; same for '''x''', '''y''' and '''z'''.
+:If a bone mesh has a vertex at (x, y, z) in its native coordinates,
+::then the actual position of that vertex in the level will be '''R''' + x '''x''' + y '''y''' + z '''z'''
+:That's the transformation defined by the matrix and the offset '''R'''.
+Reminder : the 2nd coordinate of '''R''' is the height; same for '''x''', '''y''' and '''z'''.
 ;Example:first corpse of '''00565-.CRSA''' in '''level3_Final.dat'''.