oZone3D.Net - Demoniak3D Developer Guide

Demoniak3D/LUA API: Motion-paths Management library

The HYP_MotionPath library performs general operations on motion-paths.

HYP_MotionPath.GetValueByTime
HYP_MotionPath.GetObjectCurrentTime
HYP_MotionPath.Attach

Attach

Attach allows to attach a motion-path to an object (model, mesh, light, gizmo, camera).

Syntax

HYP_MotionPath.Attach( object_name, motion_path_name, time_offset, time_step );

object_name - [STR127] - name of the object to which you wish to attach a motion-path.
motion_path_name - [STR127] - name of the motion path.
time_offset - [CLAMPED_REAL] - initial value of the time offset. Put 0.0 to start at the beginning of the motion-path (1.0 corresponds to the end of the motion-path).
time_step - [CLAMPED_REAL] - value of the increment along the motion-path. With each frame, the object moves time_step on motion-path.

Example

-- test de HYP_SetMotionPath.
HYP_MotionPath.Attach( "light01", "main_motion_path", 0.0, 0.0001 );

Remark

To detach a motion-path from an object, just replace the name of the motion-path by the "NULL" character string

HYP_SetMotionPath( "light01", "NULL", 0.0 );

GetValueByTime

GetValueByTime makes it possible to get the 3d position of a point on the motion-path for a "t" standardized time (ranging between 0.0 and 1.0).

This function is useful because it is not necessary to attach a motion-path to an object so that it moves along the motion-path. This can apply to any object whose position can be changed (via LUA), just by declaring a motion_path node in the XML script.

Syntax

x, y, z = HYP_MotionPath.GetValueByTime( motion_path_name, time );

motion_path_name - [STR127] - name of the motion path.
time - [CLAMPED_REAL] - time value. 0.0 is the beginning of the motion-path and 1.0 is the end.
x - [REAL] - X coordinate of the position
y - [REAL] - Y coordinate of the position
z - [REAL] - Z coordinate of the position

Example

time = 0.26;
x, y, z = HYP_MotionPath.GetValueByTime( "main_motion_path", time );

GetObjectCurrentTime

GetObjectCurrentTime makes it possible to get the temporal current position of an object on a motion-path. This function is useful to know for example the end of the trajectory when a motion path has been attached with the object.

Syntax

time = HYP_MotionPath.GetObjectCurrentTime( object_name );

object_name - [STR127] - name of the object.
time - [CLAMPED_REAL] - time value. 0.0 is the beginning of the motion-path and 1.0 is the end.