Can this be done?
A linear or radial array on its own is simple enough... basically you tell it start at X and go to Y, either giving it a distance between duplicates in inches, millimeters, etc in the case of a linear array, or giving it a number of degrees between duplicates in the case of a radial array.
But both of those transforms need to be done simultaneously for a spiral stair. And I can't see a way to do some combination of nested families that will work. For instance making a single step family, and then nesting that into a new family that does a linear array vertically... as far as I know, you can't nest that into then another family to do a radial array for each step independently... it will just array the whole already vertically arrayed step family as one thing. So there needs to be a way to do a "2-factor transform"... linearly move and radially rotate at the same time.
Is there a way to get the result I'm after with the family editor, or is this something that would have to move into API territory? And even then, I believe it would be a tool that would build a spiral stair from scratch every time... there's not a way to use the API to create something that could be saved as a family with all the parametric control you would want it to have, and be placeable in a project. Or am I wrong?
Thanks in advance for any insights!
