Its been discussed in the blender community that blender physics is not entirely accurate.

My question before I go into detail is: How to modify blender to have real world particle physics? I am a computer science major, so I am assuming I will need to build blender and modify the physics.

classic example how blender physics does not match real would physics is gravity on a box with a negative force above it.

enter image description here

The box picks up momentum the longer its under the influences. What should happen is eventually comes to a rest between the "force" and the force of gravity.

Also, if you have + charged particles in-between two - charged planes, it will not settle down to one point, it will zig zag continuously.

enter image description here

another thing, is that particles between a negative and positive charge plane, will move in one direction.

enter image description here

but in real life, particle accelerators have to keep oscillating the charges, or else the particle will come back to the opposite charge.

This is what should have happened in blender. Where the positive particles go past the negative plane and then come back. But for some reason, when a positive plane is added it ignores the negative plane.

lastly when trying to accelerate a particle:

enter image description here

it does not accelerate the particle, the example above has 4 objects oscillating their charges to make the particles go in a circular motion. It does this but not the way it should.

The particle should have a acceleration to it. This is the principle of cyclotrons, a particle accelerator that alternates its charges of two plates to accelerate the charged particles. Instead whats happening in blender is its stretching out the particles in a circular motion.

my hunch with the examples given is that there is something or multiple things missing in blender physics. So how do I fix this? has anyone already done this? Its been bugging me for years that blender's physics is off.

  • 2
    $\begingroup$ I'm voting to close this question as off-topic because it's about an opinion about how blender should simulate real world physics, not a bug. OP should talk with developers and propose code samples to add more (backwards compatible) realistic behaviour $\endgroup$
    – m.ardito
    Mar 15, 2018 at 7:15

1 Answer 1


Physics and particles are a tool to make movies. Not much else. They are intended to show how a steam engine works or a flock of birds in the distance. Force fields are meant to blow a smoke text away. Their job is to make stuff look good. They do not have the scope (yet) of being a physically accurate simulation of real world forces. 3D animation is the art of faking it.

When I was doing my little solar system I didn't even try the physics, I just coded a bit of python gravity myself. Also not physically accurate (no need) but I got some nice elliptical orbits. Managed some gravity slingshots, too.

So either you really need to work on the code or you might get away with python or python with C/C++ help, depending on the performance needs. Changing the source code of course means one of three outcomes: You need to merge your code every time a new version comes out, you get it committed and it becomes a part of the official release or you are stuck with a Blender version that slowly gets old.

At the last Blender Conference there was a talk about simulating quite a few million blood cells with a super computer. So there's some fancy stuff possible if you're determined.

If you want these features, start to make them happen.

  • $\begingroup$ your right, if I want blender to have real physics, I'm going to have to fix it my self. So if I do fix blender's physics, how do I get committed and part of the official release? $\endgroup$ Mar 10, 2018 at 20:28
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    $\begingroup$ Some of the limitations you illustrate are not peculiar to Blender. They would be true of any discrete simulation: i.e. a simulation that slices time and space into a finite number of chunks, and samples forces and velocities at the beginning and end of those chunks. Besides observing that Blender's primary function is to visualize, not to simulate, make sure you are aware of those limitations you can't overcome in principle, however excellent your practice. $\endgroup$
    – Robin Betts
    Mar 15, 2018 at 8:53

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