I am trying to pre-determine the Thickness property of the Solidify modifier required to completely fill the gap between two concentric, spherical shells. I know the diameter of both shells ahead of time, the shells will always be centered at (0,0,0). I would like to keep Offset = -1.0.
Using a number of examples, I have tried to back out a mathematical relationship / equation, based on the difference in the diameter of the shells. But this falls apart when the shells diameters change, but the difference between the shell diameters remains the same.
If i have a hemisphere of diameter1 = 8m, and a smaller, concentric shell with diameter1 = 2m (difference = 6m), then a Thickness value of 0.7485 will fill the gap between these two hemispherical shells.
However, if I use 2 shells that are diam1 = 100m, and diam2 = 94m (difference = 6m), then a Thickness value of 0.05975 fills in the gap between the concentric shells.
How can I pre-determine what this thickness needs to be for any case of 2 concentric shells?
Not my solution, but from one of the Blender experts:
"I'm quite sure the thickness parameter gives a direct offset from the
surface, i.e. a perfect sphere with radius R and solidify thickness X
creates a sphere with radius (R+X). This matches the first observation,
where dR=3 => thickness = 1.5 / 2 = 0.75 ~= 0.7485. The reason you don't
see these values in the second case is probably because the object is
scaled by 100/8 = 12.5 => thickness = 0.75 / 12.5 = 0.06"