Problem

You have a photographed area (a city or simply a construction site) and a completed 3MX model.

Some modifications have been made (in a city, a new building is erected or the whole block rebuilt; or on the construction site new parts are built).

How can you incorporate new photos and changes in certain areas into an existing model, so that the whole model does not have to be regenerated?

Solution

Take pictures of the new area of interest.
Make sure the new data set includes enough photos to generate a good 3D model of the area that has changed.

Create a new block (in the same project as the main area) with the new photos:

• Make an aerotriangulation on the new block by ensuring that it is correctly georeferenced to the initial block (use ground control points or drift GCP from the initial scene).
• Create a new reconstruction (new modified areas) with the same paving (SRS, size of pavement, origin of paving) as the original reconstruction.
• Produce tiles in 3MX format with the same settings (same SRS, same SRS origin). Make sure the same parameters are used for reconstruction and production so that the old and new tiles match perfectly.
• Replace old tiles with new ones in the Production directory.

Note : Using this method, there are probably differences in texture at the tile limit (due to capture at different times).