Why does Blender hair not work for life-sized models?


I have models that are real life scale in Blender. But when I add hair, the presets are way off:

Notice the 1 meter cube in both shots - for scale reference.

Example 1: Simple hair with children on lifesize head, clumps are way huge!!

In the above I have to turn the clump size all the way to -1 before hair begins to look normal again, but it’s still not perfect.

Example 2: Extremely large head scale. Now clumps look normal:

In this example I had to scale the scalp up by 10 then the clumps looked ok, but the rest of the model is now very small.

I do not have the option to scale the model because I am using motion capture software and the model must remain life-size.

Why does blender hair not work on life-size characters? Why must they be house sized before the defaults look ok?

How do I scale all values of the hair down by 10 so I can work in the desired “size space” for my application?

Thank you

By scaling the “radius” value from 0.2 to 0.02 solved the clumping issue. Strange that something called radius would be responsible for positional spacing, anyways I think I’m good now.