public sealed class LasDatasetLayer : SurfaceLayer, ArcGIS.Desktop.Core.IMetadataInfo, IMetadataSource, System.ComponentModel.INotifyPropertyChanged  

// find the first TIN layer
var tinLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<TinLayer>().FirstOrDefault();

// find the first Terrain layer
var terrainLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<TerrainLayer>().FirstOrDefault();

// find the first LAS dataset layer
var lasDatasetLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<LasDatasetLayer>().FirstOrDefault();

// find the set of surface layers
var surfacelayers = MapView.Active.Map.GetLayersAsFlattenedList().OfType<SurfaceLayer>();

//Must be on the QueuedTask.Run()

string lasPath = @"d:\Data\LASDataset.lasd";
var lasURI = new Uri(lasPath);

var lasCP = new LasDatasetLayerCreationParams(lasURI);
lasCP.Name = "My LAS Layer";
lasCP.IsVisible = false;

//Create the layer to the LAS dataset
var lasDatasetLayer = LayerFactory.Instance.CreateLayer<LasDatasetLayer>(lasCP, map);

//Must be on the QueuedTask.Run()

var lasCP_ds = new LasDatasetLayerCreationParams(lasDataset);
lasCP_ds.Name = "My LAS Layer";
lasCP_ds.IsVisible = false;

//Create the layer to the LAS dataset
var lasDatasetLayer_ds = LayerFactory.Instance.CreateLayer<LasDatasetLayer>(lasCP_ds, map);

//Must be on the QueuedTask.Run()

var lasCP_renderers = new LasDatasetLayerCreationParams(lasDataset);
lasCP_renderers.Name = "My LAS Layer";
lasCP_renderers.IsVisible = false;

// create a point elevation renderer
var ptR = new LasStretchRendererDefinition();
// accept all defaults

// create a simple edge renderer
var edgeR = new TinEdgeRendererDefintion();
// accept all defaults

// add renderers to dictionary
var l_dict = new Dictionary<SurfaceRendererTarget, TinRendererDefinition>();
l_dict.Add(SurfaceRendererTarget.Points, ptR);
l_dict.Add(SurfaceRendererTarget.Edges, edgeR);

// assign dictionary to creation params
lasCP_renderers.RendererDefinitions = l_dict;

//Create the layer to the LAS dataset
var lasDatasetLayer_rd = LayerFactory.Instance.CreateLayer<LasDatasetLayer>(lasCP_renderers, map);

// applies to LAS dataset layers only

var lasPointsClassificationRendererDef = new LasUniqueValueRendererDefinition(LasAttributeType.Classification);
// accept the defaults for color ramp, symbolTemplate, symbol scale factor

var lasDatasetLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<LasDatasetLayer>().FirstOrDefault();
if (lasDatasetLayer == null)
  return;

if (lasDatasetLayer.CanCreateRenderer(lasPointsClassificationRendererDef))
{
  CIMTinRenderer renderer = lasDatasetLayer.CreateRenderer(lasPointsClassificationRendererDef);
  if (lasDatasetLayer.CanSetRenderer(renderer, SurfaceRendererTarget.Points))
    lasDatasetLayer.SetRenderer(renderer, SurfaceRendererTarget.Points);
}