Units of particle mass and size


I have created a grid of particles (100 * 100)
And my scene uses the metric system to display measurements…

But it doesn’t show the units for particle size and mass…:spin:

Its definitely not 1Unit=1Kg nor 1Unit=1meter

Please Help!

Thanks in Advance

1 BU = 1 meter. The only place you can see it is the gravity.
What mass = 1 means, I really do not know.

From ‘The Blender Gamekit 2nd Ed.’ (for blender 2.49 but assume the same for blender 2.58)
Page 208 - The Blender Laws of Physics
“As soon as we have defined a mass for our dynamic object, it will be affected by gravity, causing it to fall until it hits another object with its bounding. The gravity has a value of 9.81 by default, if you use one Blender unit as 1m and the mass of 1.0 as one kilogram your objects will almost react as in the real world”

Hi Richard Marklew

But How would you know if 1.0= 1Kg because no matter what mass, the fall will always be the same

If You turn of gravity, and set a force Yourself at mass * gravity and it behaves the same… Then You kind of know that mass is in Kg… I’m pretty sure it is.

However, if I understand the question correct it was about particle systems… There I have no clue, but to my knowledge they don’t work in the BGE currently anyway.


Does anybody know the metric size and mass of the particles.

If the particles’ mass is set to 1 Blender Unit and the size to 1 Blender unit…
what is its metric equivalent?

I tried to create a momentum conservation scene of two particles colliding (1BU and 2BU) by I don’t know how to make the particles collide :frowning:

I was going to use this equation (mv1 + 2mv2) = (mv3 +2mv4) to calculate the metric mass of the particle …


If you change units to metric system in the Scene properties, without changing the scale, then 1 BU will become 1 mtr. Would that help you?

Yes I have tried that…
Setting the mass and size as 1, would mean that size is 1m and mass is 1Kg - that makes know sense when look at the particles

kakarot9999, I’ve merged your two threads. Please can you not create multiple threads asking the same thing. If you want a thread moved to a different forum just report it to the moderator team (small triangle at the bottom of each post)

Thank you Richard Marklew, I apologize for my actions