How I can automatically change force field strength by triggers?

I working on animation where a car (rigid body) moves on the track. I need increase speed on few places (like speed zones in games). Force fields work fine, but the problem is I can't animate force field strength, because I need to change mass, friction and other car values. So the car doesn't arrive to force fields in the same frames. I need the force field to turn on (change strength from 0 to XX) when the car hits the trigger IN, and switch off (or change from XX to 0) when car hit the trigger OUT. How can I do this?

I have this, maybe all what I need to do is set "Property on actuator. But I don't know how.

  • 1
    $\begingroup$ Are you talking about the BGE or about Blender $\endgroup$ – Monster Jun 9 '17 at 7:59
  • $\begingroup$ @Monster. The result will be animation rendered in Cycles. I don't need change anything while simulation running, only set everything on beginning and simulate physics. So, is not necessary use BGE, but also can be used for simulation and bake result to key frames. $\endgroup$ – Shubol3D Jun 9 '17 at 9:28

How about moving the object that represents the force field?

When you cant't animate the force field strength, you could move the complete force field.

| improve this answer | |
  • $\begingroup$ I don't understand how, because if I want want to move forcefields, I also need to animate them. Second problem is that forcefields doesn't loose energy by distance, so need to play with Power and that's make everything even more complicated. $\endgroup$ – Shubol3D Jun 13 '17 at 17:36
  • $\begingroup$ You can set keyframes on the object that represents the force field. $\endgroup$ – Monster Jun 28 '17 at 5:34
  • $\begingroup$ As I described: Yes I can, but this not solve my situation, because car doesnt arrive to forcefield always at the same frame. So keyframing is not very good solution :D Rigidbody simulation give little bit different result even if I change nothing and moreover, I need change car propreties and track shape. Keyframing is about luck and chance decreasing rapidly by adding more speed zones/forcefields on the track. I use keyfaming before I asked here and need run more than 100 simulations while I set one relatively simple track with one speedzone. $\endgroup$ – Shubol3D Jul 1 '17 at 9:47
  • $\begingroup$ I do not understand this. Blender is designed to create predefined animations (key frames). This means you back the result of the Blender physics into a playable animation. This results into re-producable results. The timing should always be the same unless you run a new physics simulation. Which should not happen after you reviewed the animation and before rendering. The physics simulation is a helper for setting up the scene rather than an helper on rendering, $\endgroup$ – Monster Jul 3 '17 at 9:42
  • $\begingroup$ Hi @Monster The problem is, that simulation is wrong while I set right frames when forcefields must be active. So has no sense to bake it :-( You are right: I can bake car simulation from start to frame when car meet forcefield and continue with simulation to next forcefield. But need repeat it 5 times for 5 forcefields, not mention repeat everything from beginning when I need change mass, friction, gravity center etc... Also I thing the triggers can be useful in many other situations, so should be nice know how to use them - if possible. $\endgroup$ – Shubol3D Jul 4 '17 at 18:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.