specifying an animation

[Anonymous]

I want to specify a point to move from point A to point B in increments, so basically animating the point to move in a specific path. I tried achieving this with python by having a sleep delay for a fraction of a second, but that resulted in the pausing of SOFA and it not responding. I understand that this is because the sleep was not done in the background. Is there a way of specifying an animation path for a point to follow?

[Damien Marchal]

Hi Fayad,

One solution to your problem is to use an animation controller that will update the animation at regular interval using the time of the simulation of the wall clock time depending on what you need.

You can get inspiration from the drafted animation system we implemented in the STLIB:
https://stlib.readthedocs.io/en/latest/_autosummary/splib.animation.html

Here is a simple example:

# coding: utf-8 

# splib is available here: https://github.com/SofaDefrost/STLIB
import splib

## This function is called by the animation manager at each timestep, the factor
## is updated to indicate how much has progress the animation. 
## The factor is between [0, 1] 0 is the begin of the animation, 1 is the end. 
def myanimate(target, factor, src, dst):
    t = [(dst[0]-src[0]) * factor + src[0],
         (dst[1]-src[1]) * factor + src[1],
         (dst[2]-src[2]) * factor + src[2]]    
    
    print("I'm updating the position using: ", factor, " new pos is", t) 
    target.position = t

def createScene(rootNode):
    from splib.animation import animate, AnimationManager    

    ## This will create a single AnimationManager python script controller that will animate all the 
    ## animation on the scene. 
    AnimationManager(rootNode)

    # The object    
    t = rootNode.createObject("MechanicalObject", position=[0,0,0])
    t.showObject=True
    t.showObjectScale=10

    # This fire up an animation, 
    # The movement is computed using the "myanimate" function 
    # The target of the animation is the 't' object 
    # This animation will have 0.5 second duration (simulation time)
    # 'ping-pong' means that the animation will repeat to-from.  
    animate(myanimate, {"target" : t, "src" : [-1.0,-1.0,0], "dst" :  [+1.0, 2.0,0]}, duration=5.0, mode="pingpong" )

Hope this helps.

Regards,
Damien.

[Damien Marchal]

H Fayad,

Is this problem solved ?

Regards,
Damien

[Anonymous]

Yes thanks.

Best,
Fayad

[Author]

Posts