createterrain.swift

//Valley of the 10 Peaks
//NE & SW Corners
var minLat = 51.20
var minLon = -116.28
var maxLat = 51.32
var maxLon = -116.12

var terrainNode: TerrainNode?
var terrainNodeScale = SCNVector3(0.0003, 0.0003, 0.0003) // Scale down map (otherwise it's far too big)

func createTerrain() {
    terrainNode = TerrainNode(minLat: minLat, maxLat: maxLat,
                              minLon: minLon, maxLon: maxLon)
    if let terrainNode = terrainNode {
        terrainNode.scale = terrainNodeScale // Scale down map
        terrainNode.geometry?.materials = defaultMaterials()
        scene.rootNode.addChildNode(terrainNode)

        //create terrain geometry based on mapbox elevation data
        terrainNode.fetchTerrainHeights(minWallHeight: 100.0, enableDynamicShadows: true, progress: { progress, total in }, completion: {
            NSLog("Terrain load complete")

        })

        terrainNode.fetchTerrainTexture("mapbox/satellite-v9", progress: { progress, total in }, completion: { image in
            NSLog("Texture load complete")
            //apply the satellite image to the terrain mesh
            terrainNode.geometry?.materials[4].diffuse.contents = image
        })
    }
}

// Create default materials for each side of the terrain node
func defaultMaterials() -> [SCNMaterial] {
    let groundImage = SCNMaterial()
    groundImage.diffuse.contents = UIColor.darkGray
    groundImage.name = "Ground texture"

    let sideMaterial = SCNMaterial()
    sideMaterial.diffuse.contents = UIColor.darkGray
    sideMaterial.isDoubleSided = true
    sideMaterial.name = "Side"

    let bottomMaterial = SCNMaterial()
    bottomMaterial.diffuse.contents = UIColor.black
    bottomMaterial.name = "Bottom"

    return [sideMaterial, sideMaterial, sideMaterial, sideMaterial, groundImage, bottomMaterial]
}