velocity multiply

[Saca]

hi,
I want to multilly velocity strenght and keep position.
vely slow moving particles are, but i want to set strong motion blur.(VRay)

i have tryied C# script, but set strong velocity, and the positionis changed.

by the way, In houdini, it's very easy.(point wrangle example: @v*=5
I'm good if get similar technique in tyFlow.

thanks

Code:

public void simulationStep()
{    
    for (int i = 0; i < eventParticleCount; i++)
    {
        int sInx = tf.GetSimIndex(i);

        float eventAge = tf.GetEventAge(sInx); //then we get each particle's event-age

        if (eventAge == 0)
        {
            Point3 oriPos = tf.GetPos(sInx); //** ORIGINAL POSITION
            float velMult = 2; //** VELOVITY_Multiply
            tf.SetVel(sInx,tf.GetVel(sInx)*velMult);
            tf.SetPos(sInx, oriPos);
        }        
    }    
}