private void CalculateTextureWeights()
{
lowMark = 15 * scale.Y;
highMark = 180 * scale.Y;
for (int i = 0; i < vertices.Length; i++)
{
float height = vertices[i].Position.Y;
double normalAngle = GMath.AngleOfIncline(vertices[i].Normal);
Vector4 weights = Vector4.Zero; // start all weights at 0
if (height < lowMark) // height is in the lower third
{
weights.Y = height / lowMark; // percent weight 2
weights.X = 1 - weights.Y; // percent weight 1
}
else if (height < highMark) // height is in the middle third
{
weights.Z = (height - lowMark) / (highMark - lowMark); // percent weight 3
weights.Y = 1 - weights.Z; // percent weight 2
}
else // height is in the top third
{
weights.W = (height - highMark) / (255 - highMark) * (float)(90 - normalAngle) / 90.0f; // percent weight 4
weights.Z = 1 - weights.W; // percent weight 3
}
// surfaces which have steep surfaces should be rocky
if (normalAngle < 50)
{
float rockyness = MathHelper.Clamp((float)(90 - normalAngle) / 90.0f, 0, 1);
weights *= 1 - rockyness;
weights.W += rockyness;
}
// surfaces which have shallow angles mix in some of the third texture
if (normalAngle > 75 && vertices[i].Position.Y > lowMark)
{
weights *= 0.4f;
weights.Z += 0.6f;
}
vertices[i].TextureWeights = weights;
}
}
/// <summary>
/// Creates and connects all nodes in the grid
/// </summary>
private void BuildGrid(Sim.Environment.Terrain terrain)
{
// create the nodes at their proper locations
nodes = new Node[width * length];
for (int z = 0; z < length; z++)
{
for (int x = 0; x < width; x++)
{
int i = x + z * width;
float y = terrain.CalculateHeight(x * spacing, z * spacing);
nodes[i] = new Node(new Vector3(x * spacing, y, z * spacing));
if (y < 5) // underwater
{
nodes[i].State = NodeState.Invalid;
}
else if (GMath.AngleOfIncline(terrain.CalculateSurfaceNormal(x * spacing, z * spacing)) < 50)
{
nodes[i].State = NodeState.Invalid;
}
}
}
// connect adjacent nodes
for (int z = 0; z < length; z++)
{
for (int x = 0; x < width; x++)
{
Node n = nodes[x + z * width];
// adjacent nodes exist in all 8 directions if the current node is part of the
// interior of the grid; if the node is on an edge, certain spots are empty
bool addN = z > 0;
bool addS = z < length - 1;
bool addW = x > 0;
bool addE = x < width - 1;
if (addN)
{
n.AdjacentNodes.Add(nodes[x + (z - 1) * width]); // N
if (addE)
{
n.AdjacentNodes.Add(nodes[(x + 1) + (z - 1) * width]); // NE
}
if (addW)
{
n.AdjacentNodes.Add(nodes[(x - 1) + (z - 1) * width]); // NW
}
}
if (addS)
{
n.AdjacentNodes.Add(nodes[x + (z + 1) * width]); // S
if (addE)
{
n.AdjacentNodes.Add(nodes[(x + 1) + (z + 1) * width]); // SE
}
if (addW)
{
n.AdjacentNodes.Add(nodes[(x - 1) + (z + 1) * width]); // SW
}
}
if (addE)
{
n.AdjacentNodes.Add(nodes[(x + 1) + z * width]); // E
}
if (addW)
{
n.AdjacentNodes.Add(nodes[(x - 1) + z * width]); // W
}
}
}
}