Application note: moving part nested sequences

Some animations involve different kinds of movements. For instance, the rotation of the wheel on the ground must be combined with the gear extension/retraction. The wheel rotation have to be nested into the gear animation:

This application note will show you how to proceed.

Assumptions: I suppose the sub-assy representing the gear strut is called GSTRUT and the sub-assy representing the wheel is called WHEEL. The coordinates of the center of rotation of the wheel are (6, 1.5, -4) and the coordinates of the center of rotation of the gear are (5.5, 1.5, -1).

Rotation of the wheel
We have to perform the following operations:

The instruction sequence is as follows:
WHEEL01 WHEEL      WHEEL02
        VECTOR     6,1.5,-4,0,0,0
        RETURN
WHEEL02 TRANS/ROT  WHEEL
        VECTOR     -6,-1.5,4,0,0,0
        RETURN

Gear movement
We have to perform the following operations:

Caution ! This operation must apply to the gear strut as well as to the rotating wheel.

The instruction sequence is as follows:
        GEAR RBANK GEAR01
        VECTOR     5.5,1.5,-1,0,0,0
        RETURN
GEAR01  TRANS/ROT  GEAR02
        VECTOR     -5.5,-1.5,1,0,0,0
        RETURN
GEAR02  GOSUB      GSTRUT
        GOSUB      WHEEL01
        RETURN

The overall sequence is the following:
        GEAR RBANK GEAR01
        VECTOR     5.5,1.5,-1,0,0,0
        RETURN
GEAR01  TRANS/ROT  GEAR02
        VECTOR     -5.5,-1.5,1,0,0,0
        RETURN
GEAR02  GOSUB      GSTRUT
        GOSUB      WHEEL01
        RETURN
WHEEL01 WHEEL      WHEEL02
        VECTOR     6,1.5,-4,0,0,0
        RETURN
WHEEL02 TRANS/ROT  WHEEL
        VECTOR     -6,-1.5,4,0,0,0
        RETURN

Piece of cake, isn't it!


copyright Hervé Devred, 2001