I know that THREE.js has importers from various 3d graphics formats.
Is there an importer suitable to display a model created in 3dStudioMax? And if there is not one, is there a way to convert a 3dStudioMax model in something that can be imported in THREE.js?
You have two options:
1) Use ThreeJSExporter.ms but take into account that is no longer mantained:
https://github.com/mrdoob/three.js/tree/master/utils/exporters/max
2) (Recommended) Use OBJ exporter option in 3DS Max. Then use convert_obj_three.py script available here:
https://github.com/mrdoob/three.js/blob/master/utils/converters/obj/convert_obj_three.py
More detailed info in my issue on Three.js's Github: