According to “Creating a flat rectangular TIN” (visible if you scroll down a bit in https://help.sketchup.com/en/article/3000132) , I’m supposed to be able to edit the default (10’) Sandbox grid spacing during the last of three steps required to create a grid. The first two steps - creating the 2D grid - work as expected, but entering a grid spacing into the box (third step) either does nothing, or lops off the grid to the size I’ve entered.
My actual intended use: I create an 800’ x 900’ grid (first two clicks), then edit the grid spacing to 25’. Result: The 800’ x 900’ grid comes up, with the default 10’ spacing. Entering 25’ in the last step to change grid-spacing changes the value-box entry, but leaves the grid exactly as it was before, with the default 10’ spacing.
My generic test: create a 100’ x 100’ grid (first two clicks), then edit the grid spacing to 20’. Result: a total dimension of 20’ x 100’, grid spacing still at 10’.
If this is a bug that I’m stuck with, I’m wondering whether there’s really any great magic to the grid once it’s created to my specs ANYWAY - or if I can just do the same thing “manually,” eg by drawing lines and then multi-copying them over my specified intervals along X- and Y-axes. My intent was to manually enter DTS values from an autocad file, shown on a 25’ grid, in order to do a volume calculation for the ‘terrain’ to be removed to reach the design contours. (Seems like I could have done it by now using that manual method, vs. all the futzing with the non-working grid…)