Open The Door

Rule-based control of animation time and particle time is one of the most powerful Non Linear Animation feature of thinkingParticles.

In the example animation shown below, a door opens whenever a particle gets near to it. This animation doesn't use a standard linear keyframe animation approach. Particles do in fact control the animation of the door!
Animating this door by hand, would mean that you have to decide when and how fast the door needs to open. However, as the particle system could change at any time it would mean to redo the animation over and over again. This can be easily avoided by using the Non Linear Animation approach in thinkingParticles.

An ObjectToParticle node was used to turn the door into a particle. Now, that the door is a particle, it's possible to use any rule based methods to control the animation by a condition or operator. In the case shown below, a simple distance operator was used to measure the distance between the door and the approaching particles. The door opening is fully automatic. No keyframe is necessary since the animation is controlled by rules alone.

Another remarkable feature is the ability to control the speed at which the door opens by setting the particle velocity. Faster particles will force the door to open faster. Another idea would be to open the door based on the impact of the particles. If 300 particles hit the door, the door opens. Once again, you've seen how thinkingParticles offers limitless possibilities for any dedicated CG artist.