var slopeFaceClassBreaksQuantile = new TinFaceClassBreaksRendererDefinition(TerrainDrawCursorType.FaceSlope);
slopeFaceClassBreaksQuantile.ClassificationMethod = ClassificationMethod.Quantile;
// accept default breakCount, symbolTemplate, color ramp
if (surfaceLayer.CanCreateRenderer(slopeFaceClassBreaksQuantile))
{
CIMTinRenderer renderer = surfaceLayer.CreateRenderer(slopeFaceClassBreaksQuantile);
if (surfaceLayer.CanSetRenderer(renderer, SurfaceRendererTarget.Surface))
surfaceLayer.SetRenderer(renderer, SurfaceRendererTarget.Surface);
}