Today I loaded an old image that displayed the 3D model in WEB ODM without any tweaking being required. I looked at the problem history page and found that 3D mapping did not display in August 2021. The solution was to click on “FULL EXTENT”.
I tried this fix and it opened the 3D model page that up to the point of clicking FULL EXTENT had been a blank page.
Something has gone out again or I have picked up a local bug.
Strangely, for some tasks the 3D model does appear without the need to click on Full Extent. With my M2P drone I need to use Full Extent, but the model appears without needing to do that with my phone camera models. Maybe that is useful in helping to determine the problem?