Overlay of triangulated mesh and images

Hi guys, I'm rather new to Cesium and couldn't find a way or a starting point in the documentation to my problem.

I'm working with Photoscan and have my model as well as my orthophoto as end product. Now I'm looking for a way to overlay my own terrain (triangulated mesh or the full 3D model) with my orthophoto.

Might someone point me in the right direction on this? Thanks a lot in advance!

Can your terrain model be exported as a DSM or a GeoTIFF? If so, then you could upload it to Cesium.com/ion, then serve it as custom terrain, and put your own imagery layer on top of it:

https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/?src=Imagery%20Layers.html

If PhotoScan can output a photogrammetry model with images embedded on it (like an OBJ) you can also then upload that to Cesium ion to convert it to 3D Tiles and visualize it that way.

Let me know if that helps!