The following warning message is displayed when trying to add a terrain dataset to ArcScene.
"Could not add the specified data object to the scene. Try using a smaller subset."
Terrain datasets are not supported in ArcScene. Terrains are supported in ArcMap and ArcGlobe.
For detailed information on converting at a specific Pyramid Level Resolution, restricting the Maximum Number of Nodes, or setting a Clip to Extent see: Creating a TIN surface from a terrain dataset