I installed the Microstation Connect Edition Update 6 and I can directly attach *.3SM files through the reality mesh tools. I have attempted several times to export a Microstation model and a *.3SM mesh into LumenRT. The Microstation model exports without issue, but the *.3SM file does not appear in LumenRT: how can I solve this situation?
You can direct import the *.3sm file into LumenRT.
Click on Terrain & Ocean> Add ScalabeMesh:
If you need to insert the scalable terrain as an object (so you should be able to move it) please use Add misc > Import Object > *.3sm files: