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/vis/scene/create
/vis/scene/add/volume
/vis/open OGLSX
/vis/scene/refresh

There is a Python script that converts LCDD to GDML and views it in ROOT: DrawLCDD.py

1. The script requires ROOT to be installed and in the path. It also requires ROOT to have the gdml module, but that is pretty standard by now.
2. Invoke with -h for options. Main useful option would be to call with -N to only make the lcdd_cleaned.gdml file.
3. It cannot show tessellated objects. These cause ROOT to crash, so tessellated stuff gets stripped.
4. It pollutes your working directory with two files: lcdd_cleaned.gdml and lcdd_cleaned.C. The first is a pure gdml file, the second is a root script to render it.
5. You can rotate and zoom in, make cutaway planes etc all using ROOT interactively. It is useful for checking your geometry.

Viewing GDML

ROOT can view GDML, but not tessellated volumes: How do I visualize with ROOT

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