For Distance, enter the distance shown divided by a fraction that represents the percentage you’re after…
Apart from the fraction to percentage math problem with this “workaround” is that for the next curve you want to do this on, the last distance value is still shown, so you have to analyze the curve length manually which adds even more steps…
(I know Grasshopper has this feature, but I’d like to know if Rhino has it too.)
DETAILS: When Rhino expects point coordinates, hold Shift key and move the cursor to Osnap control. The buttons will change. For example, Disable button will become Percent button. Click the Percent button to place temporary points on the curve. Follow the guidance in the Command prompt. (You do not not need to set the Point Osnap because it is automatic.)
I just tried this, but I can’t get those snaps to show. It always says Project and Disable for me, even when I try a Split on a curve and the Point option…
Project and Disable are different buttons. Move the cursor to Disable button, NOT to Project button. By the way, the Osnap Percent exists in Rhino 6 and Rhino 7.
They mark multiples of the percentage distance, you then have to select one to place the point - and don’t get too excited: you can only select one of them…
Hmm… well, it does seem that you can place your regular snap anchors (using control) on top of these weird black things and have them stick around after the first click…