Item Motion Class

Note

These interface classes are not intended for direct usage; rather they should be inherited by your own subclass. (See Anatomy of a LightWave Python Plug-in)

Handler

class lwsdk.IItemMotion(self)

Bases: lwsdk.lwsdk.IHandlerFuncs, lwsdk.lwsdk.IInterfaceFuncs, lwsdk.lwsdk.IGizmoFuncs, lwsdk.lwsdk.IItemFuncs

Proxy of C++ PCore::IItemMotion class

 evaluate(LWItemMotionAccess arg0)

This is where the motion handler does its work. LightWave calls the evaluation function at every point in the animation at which an item's motion parameters need to be calculated. The LWItemMotionAccess instance (described below) tells you the item being animated and the frame and time of the evaluation, and provides functions to set motion parameters for the current time and to get the item's motion parameters for any time.

 flags() → unsigned int

Returns an integer containing flags combined using bitwise-or. Currently the only flag is lwsdk.LWIMF_AFTERIK, which specifies that the plug-in will be evaluated after LightWave has performed the inverse kinematics calculations for the item.

Access

class lwsdk.LWItemMotionAccess(self, LWItemMotionAccess source_)

Bases: object

Proxy of C++ PCore::LWItemMotionAccess class

 animationPass → int

The animation pass for which the motion should be evaluated. It holds one of the following values:

lwsdk.LWANIMPASS_MAIN
lwsdk.LWANIMPASS_PRELIMINARY
lwsdk.LWANIMPASS_BLUR
lwsdk.LWANIMPASS_RESTORE
lwsdk.LWANIMPASS_DYNAMICS

 frame → LWFrame

The frame number at which the motion should be evaluated.

 getParam(LWItemParam arg1, LWTime arg2) → LWDVector

Returns a motion parameter for the item at any given time. Only one of lwsdk.LWIP_POSITION, lwsdk.LWIP_ROTATION or lwsdk.LWIP_SCALING may supplied as arg1.

 item → LWItemID

The ID for the item to be affected by the procedural motion.

 setParam(LWItemParam arg1, LWDVector arg2)

Used by the evaluation function to set the computed motion of the item at the current time. Only one of lwsdk.LWIP_POSITION, lwsdk.LWIP_ROTATION or lwsdk.LWIP_SCALING may be supplied as arg1.

 time → LWTime

The animation time for which the motion should be evaluated.

Factory

class lwsdk.ItemMotionFactory(name, klass)

Bases: lwsdk.lwsdk.IItemMotionFactory

Default Python Factory for IItemMotion

 create(context)

 destroy(instance)

Example

class sol(lwsdk.IItemMotion):
    def __init__(self, context):
        super(sol, self).__init__()
        self._itemid = context
        self._name = lwsdk.LWItemInfo().name(self._itemid)

        # pre-calculate some values for performance

        self._r = planet_au[self._name] * AU;
        self._s = (planet_r[self._name] * math.pow(10, 3)) / AU;
        self._b = planet_tilt[self._name];
[...]
    # LWItemMotion ----------------------------------------
    def evaluate(self, ma):
        a = ((ma.time * self._scale) / self._p) * (2 * math.pi)

        x = (self._r / AU) * math.cos(a)
        z = (self._r / AU) * math.sin(a)

        ma.setParam(lwsdk.LWIP_POSITION, [x, 0.0, z])
        ma.setParam(lwsdk.LWIP_SCALING,  [self._s] * 3)
        ma.setParam(lwsdk.LWIP_ROTATION, [0.0, 0.0, self._b])
[...]
ServerRecord = { lwsdk.ItemMotionFactory("LW_PySol", sol) : ServerTagInfo }