private void btnTileInfo_Click(object sender, EventArgs e)
{
Vector3[] v3 = new Vector3[5];
// python demo data in ECEF coordinates
v3[0] = new Vector3(4480363.47619142, 580530.98724711, 4487574.82445706);
v3[1] = new Vector3(4507665.32245697, 584068.55018155, 4459851.33224541);
v3[2] = new Vector3(4492226.98875439, 596087.14785771, 4473732.87770479);
v3[3] = new Vector3(4504029.82280181, 611720.56972904, 4459884.3617184);
v3[4] = new Vector3(4476724.14024925, 608012.01353714, 4487581.96623555);
TileInfo tf = new TileInfo();
var hdr = tf.CalculateHeaderInfo(ref v3, false);
var hop = HorizonOcclusionPoint.FromPoints(v3, tf.BoundingSphere);
// python demo var hdr = tf.CalculateHeaderInfo(ref v3, false);
listBox1.Items.Add($"Header Info CenterXYZ:{hdr.CenterX} , {hdr.CenterY}, {hdr.CenterZ}");
listBox1.Items.Add($"Header Info HorizonOcclusionPoint: {hop.X} , {hop.Y} , {hop.Z}");
}
/// <summary>
///
/// </summary>
/// <param name="bbox"></param>
/// <returns></returns>
private ElevationData MakeTileDEM(LLBoundingBox bbox)
{
// Steps
// Using bounding box get elevation data for tile
// Calculate header info
Vector3[] ecefPoints;
ElevationData ed = GetData(bbox, out ecefPoints);
// Work out bounding sphere
TileInfo tileInfo = new TileInfo();
var hdr = tileInfo.CalculateHeaderInfo(ref ecefPoints, false);
ed.CenterX = hdr.CenterX;
ed.CenterY = hdr.CenterY;
ed.CenterZ = hdr.CenterZ;
ed.BoundingSphereCenterX = hdr.CenterX;
ed.BoundingSphereCenterY = hdr.CenterY;
ed.BoundingSphereCenterZ = hdr.CenterZ;
ed.BoundingSphereRadius = hdr.BoundingSphereRadius;
// Work out HorizonOcclusionPoint
var hop = HorizonOcclusionPoint.FromPoints(ecefPoints, tileInfo.BoundingSphere);
ed.HorizonOcclusionPointX = hop.X;
ed.HorizonOcclusionPointY = hop.Y;
ed.HorizonOcclusionPointZ = hop.Z;
/* Quicker cheat method untested
* ed.HorizonOcclusionPointX = hdr.CenterX;
* ed.HorizonOcclusionPointY = hdr.CenterY;
* ed.HorizonOcclusionPointZ = maxElev;
*/
// todo lighting
return(ed);
}
/// <summary>
/// Compute all header info
/// </summary>
/// <returns></returns>
private void ComputeHeaderInfo()
{
// Work out bounding sphere for Cesium tile
TileInfo tileInfo = new TileInfo();
var tileHeader = tileInfo.CalculateHeaderInfo(ref TileData.EcefPoints);
TileData.CenterX = tileHeader.CenterX;
TileData.CenterY = tileHeader.CenterY;
TileData.CenterZ = tileHeader.CenterZ;
TileData.BoundingSphereCenterX = tileHeader.CenterX;
TileData.BoundingSphereCenterY = tileHeader.CenterY;
TileData.BoundingSphereCenterZ = tileHeader.CenterZ;
TileData.BoundingSphereRadius = tileHeader.BoundingSphereRadius;
// Work out tile HorizonOcclusionPoint
var hop = HorizonOcclusionPoint.FromPoints(ref TileData.EcefPoints, tileInfo.BoundingSphere);
TileData.HorizonOcclusionPointX = hop.X;
TileData.HorizonOcclusionPointY = hop.Y;
TileData.HorizonOcclusionPointZ = hop.Z;
// If lighting is required add code here
}
private void btnMyData_Click(object sender, EventArgs e)
{
// Array of Lat Long
Vector3[] v3 = new Vector3[16];
v3[0] = new Vector3(7.3828125, 44.6484375, 303.3);
v3[1] = new Vector3(7.3828125, 45.0, 320.2);
v3[2] = new Vector3(7.5585937, 44.82421875, 310.2);
v3[3] = new Vector3(7.3828125, 44.6484375, 303.3);
v3[4] = new Vector3(7.3828125, 44.6484375, 303.3);
v3[5] = new Vector3(7.734375, 44.6484375, 350.3);
v3[6] = new Vector3(7.5585937, 44.82421875, 310.2);
v3[7] = new Vector3(7.3828125, 44.6484375, 303.3);
v3[8] = new Vector3(7.734375, 44.6484375, 350.3);
v3[9] = new Vector3(7.734375, 45.0, 330.3);
v3[10] = new Vector3(7.5585937, 44.82421875, 310.2);
v3[11] = new Vector3(7.734375, 44.6484375, 350.3);
v3[12] = new Vector3(7.734375, 45.0, 330.3);
v3[13] = new Vector3(7.5585937, 44.82421875, 310.2);
v3[14] = new Vector3(7.3828125, 45.0, 320.2);
v3[15] = new Vector3(7.734375, 45.0, 330.3);
// Convert to ECEF coords
Vector3[] points = new Vector3[5];
for (int i = 0; i < 5; i++)
{
points[i] = Coord.geo_to_ecef(v3[i]);
}
// Now get tile header info
TileInfo tf = new TileInfo();
var hdr = tf.CalculateHeaderInfo(ref points, false);
var hop = HorizonOcclusionPoint.FromPoints(points, tf.BoundingSphere);
listBox1.Items.Add($"Header Info CenterXYZ:{hdr.CenterX} , {hdr.CenterY}, {hdr.CenterZ}");
listBox1.Items.Add($"Header Info HorizonOcclusionPoint: {hop.X} , {hop.Y} , {hop.Z}");
}
/*
* https://cesium.com/blog/2013/05/09/computing-the-horizon-occlusion-point/
* private computeMagnitude(ellipsoid, position, scaledSpaceDirectionToPoint)
* {
* var scaledSpacePosition = ellipsoid.transformPositionToScaledSpace(position);
* var magnitudeSquared = scaledSpacePosition.magnitudeSquared();
* var magnitude = Math.sqrt(magnitudeSquared);
* var direction = scaledSpacePosition.divideByScalar(magnitude);
*
* // For the purpose of this computation, points below the ellipsoid
* // are considered to be on it instead.
* magnitudeSquared = Math.max(1.0, magnitudeSquared);
* magnitude = Math.max(1.0, magnitude);
*
* var cosAlpha = direction.dot(scaledSpaceDirectionToPoint);
* var sinAlpha = direction.cross(scaledSpaceDirectionToPoint).magnitude();
* var cosBeta = 1.0 / magnitude;
* var sinBeta = Math.sqrt(magnitudeSquared - 1.0) * cosBeta;
*
* return 1.0 / (cosAlpha * cosBeta - sinAlpha * sinBeta);
* }
*/
/// <summary>
/// By LatLon
/// </summary>
/// <param name="bb"></param>
/// <returns></returns>
private ElevationData MakeTileDEM(LLBoundingBox bb)
{
// todo we also need to comput header info for the quantized mesh
Vector2 v;
v.X = 0;
v.Y = 0;
int x2 = 0;
int y2 = 0;
int PixelCount = GridSize - 1;
var DoRandom = false;
int HgtMode = 2;
float minElev = float.PositiveInfinity;
float maxElev = float.NegativeInfinity;
Random rnd = new Random();
ElevationData ed = new ElevationData(GridSize);
var midPt = bb.GetCenter();
// var pt2 = Coord.geo_to_ecef(new Vector3( MapUtil.Deg2Rad(midPt.Longitude), MapUtil.Deg2Rad(midPt.Latitude),0)); // zero elevation for now
var pt = MapUtil.LatLonToEcef(midPt.Latitude, midPt.Longitude, 0); // zero elevation for now
Vector3[] ecefPoints = new Vector3[GridSize * GridSize];
try
{
// we are going to walk up from sw to ne for returning dem in latlon coordinates
var yRange = bb.North - bb.South;
var xRange = bb.East - bb.West;
var xStep = xRange / PixelCount;
var yStep = yRange / PixelCount;
int i = 0;
float hgt = 0;
for (int y = 0; y < GridSize; y++)
{
for (int x = 0; x < GridSize; x++)
{
var lat = bb.South + (y * yStep);
var lon = bb.West + (x * xStep);
v = MapProject(lat, lon); // MapProject is lat long
if (v.X >= Width)
{
v.X = Width - 1;
}
if (v.Y >= Depth)
{
v.Y = Depth - 1;
}
if (v.X < 0)
{
v.X = 0;
}
if (v.Y < 0)
{
v.Y = 0;
}
x2 = (int)v.X;
y2 = (int)v.Y;
//hgt = 0;
// if (i == 4)
// hgt = 100;
if (HgtMode == 1)
{
ed.Elev[i] = rnd.Next(1, 8000);
}
else if (HgtMode == 2)
{
ed.Elev[i] = 0;
if (lat >= -43.548006 & lat <= -43.547679)
{
if (lon >= 172.632951 & lon <= 172.633542)
{
ed.Elev[i] = (float)10.0;
}
}
}
else
{
hgt = Map.GetPixel(x2, y2).GetBrightness(); // 0=black, 1= white
ed.Elev[i] = MapUtil.Lerp(0, 1, ElevMin, ElevMax, hgt);
}
if (ed.Elev[i] < minElev)
{
minElev = ed.Elev[i];
}
if (ed.Elev[i] > maxElev)
{
maxElev = ed.Elev[i];
}
// Make ecef point list for later calculations
ecefPoints[i] = Coord.geo_to_ecef(new Vector3()
{
X = MapUtil.Deg2Rad(lon), Y = MapUtil.Deg2Rad(lat), Z = ed.Elev[i]
});
i++;
}
}
}
catch (Exception ex)
{
#if DEBUG
System.Diagnostics.Debug.WriteLine($"**** MakeTileDEM Exception ****:{ex} v:{v} x2{x2} y2{y2} ");
// file writer System.Diagnostics.Trace.WriteLine($"**** MakeTileDEM Exception *********:{ex} v:{v} x2{x2} y2{y2} ");
#endif
}
// todo now make a ecfc array to calculate header info
TileInfo tileInfo = new TileInfo();
var hdr = tileInfo.CalculateHeaderInfo(ref ecefPoints, false);
ed.CenterX = hdr.CenterX;
ed.CenterY = hdr.CenterY;
ed.CenterZ = hdr.CenterZ;
ed.BoundingSphereCenterX = hdr.CenterX;
ed.BoundingSphereCenterY = hdr.CenterY;
ed.BoundingSphereCenterZ = hdr.CenterZ;
ed.BoundingSphereRadius = hdr.BoundingSphereRadius;
ed.MaximumHeight = maxElev;
ed.MinimumHeight = minElev;
var hop = HorizonOcclusionPoint.FromPoints(ecefPoints, tileInfo.BoundingSphere);
ed.HorizonOcclusionPointX = hop.X;
ed.HorizonOcclusionPointY = hop.Y;
ed.HorizonOcclusionPointZ = hop.Z;
/*
* // FIXME: is there a better choice for a horizon occlusion point?
* // Currently it's the center of tile elevated to bbox's max Z
* header.horizon_occlusion = c;
* header.horizon_occlusion.z = bbox.max.z;
*
*
* ed.HorizonOcclusionPointX = hdr.CenterX;
* ed.HorizonOcclusionPointY = hdr.CenterY;
* ed.HorizonOcclusionPointZ = maxElev;
*/
return(ed);
}
