In a nutshell, whenever the Measurements box is available, you can use this to evaluate an expression and send the result to SketchUp. To clarify, scalar values such as lengths and radius - it doesn't know about coordinate pairs, or length units.
Type in expressions just like you would write them, use parenthesis for grouping.
It uses VBScript to eval the textbox, so you can also use any Math that VBS supports including:
- +, -, *, /, abs(), atn(), cos(), exp(), hex(), int(), fix(), log(), oct(), rnd(), round(), sgn(), sin(), sqr(), tan()
Use the Test button to make sure it uses the correct SketchUp Window. It looks for the first window that matches the title text. Sometimes, it finds non-Sketchup windows that happen to also match.
Once you're sure it's getting the right window, then anytime the Measurements is expecting a value, you can Alt-Tab to the calc, enter a calculation, and hit Send. The calculated value is sent, along with the ENTER key.
Installing - download the .zip, extract the single .hta file. It does not need to be located in any special place. Double-click to run it from anywhere, at any time.
Alpha version, ugly interface but that can be fixed. I just need to know if it works and if anyone's interested.