private void AdjustVerticesForImpact(Vector3 impactPoint, Vector3 impactForce,
Meshinator.ImpactShapes impactShape, Meshinator.ImpactTypes impactType)
{
// Get the radius from the impactPoint that we'll be looking into
float impactRadius = impactForce.magnitude;
// Figure out how many vertices we will move
Dictionary <int, float> movedVertexToForceMagnitudeMap = new Dictionary <int, float>();
for (int i = 0; i < m_Vertices.Count; i++)
{
Vector3 vertex = m_Vertices[i];
// Figure out the distance from the impact to this vector in different ways to
// determine the shape of the impact
Vector3 distanceVector = Vector3.zero;
switch (impactShape)
{
case Meshinator.ImpactShapes.FlatImpact:
distanceVector = Vector3.Project(vertex - impactPoint, impactForce.normalized);
break;
case Meshinator.ImpactShapes.SphericalImpact:
distanceVector = vertex - impactPoint;
break;
}
// If we're using a FlatImpact and the angle between the impact vector, and this vertex to the point
// if impact is greater than 90 degrees, then make the distance the negative of itself. This fixes some
// weird issues that pop up by the physics system determining that the point of collision is inside the
// mesh instead of on the surface
float distance = distanceVector.magnitude;
if (impactShape == Meshinator.ImpactShapes.FlatImpact &&
Vector3.Angle(vertex - impactPoint, impactForce) > 90f)
{
distance = -distance;
}
// If this vertex is within the impact radius, then we'll be moving this vertex.
// Store the magnitude of the force by which this vertex will be moved
float vertexForceMagnitude = Mathf.Max(0, (impactRadius - distance)) * c_CompressionResistance;
if (distance < impactRadius && vertexForceMagnitude > 0)
{
movedVertexToForceMagnitudeMap.Add(i, vertexForceMagnitude);
}
}
// Depending on our ImpactType, deform the mesh appropriately
switch (impactType)
{
case Meshinator.ImpactTypes.Compression:
CompressMeshVertices(movedVertexToForceMagnitudeMap, impactForce);
break;
case Meshinator.ImpactTypes.Fracture:
FractureMeshVertices(movedVertexToForceMagnitudeMap, impactForce);
break;
}
}
public void Impact(Vector3 impactPoint, Vector3 impactForce, Meshinator.ImpactShapes impactShape, Meshinator.ImpactTypes impactType)
{
// Look through all triangles to see which ones are within the impactForce from the impactPoint,
// and measure the area of every triangle in the list
Dictionary <int, float> triangleIndexToTriangleArea = new Dictionary <int, float>();
foreach (int triangleIndex in GetIntersectedTriangleIndices(impactPoint, impactForce.magnitude))
{
float areaOfTriangle = GetAreaOfTriangle(triangleIndex);
triangleIndexToTriangleArea.Add(triangleIndex, areaOfTriangle);
}
// Keep breaking down the largest triangle until there are more than c_MinTrianglesPerImpact
// triangles in the list
while (triangleIndexToTriangleArea.Keys.Count < c_MinTrianglesPerImpact)
{
// If we have 64988 vertices or more, we can't add any more or we risk going over the
// 65000 limit, which causes problems for unity.
if (m_Vertices.Count > 64988)
{
break;
}
// Get the index of the biggest triangle in our dictionary
int indexOfLargestTriangle = GetIndexOfLargestTriangle(triangleIndexToTriangleArea);
// Break that triangle down and remove it from the dictionary
List <int> newTriangleIndices = BreakDownTriangle(indexOfLargestTriangle);
triangleIndexToTriangleArea.Remove(indexOfLargestTriangle);
// Measure the areas of the resulting triangles, and add them to the dictionary
foreach (int triangleIndex in newTriangleIndices)
{
// Make sure each triangle is still intersected by our force before we add it back to the list
if (IsTriangleIndexIntersected(triangleIndex, impactPoint, impactForce.magnitude))
{
float areaOfTriangle = GetAreaOfTriangle(triangleIndex);
triangleIndexToTriangleArea.Add(triangleIndex, areaOfTriangle);
}
}
}
// Now that we have the proper vertices and triangles, actually go about deforming the mesh
// by moving the vertices around.
AdjustVerticesForImpact(impactPoint, impactForce, impactShape, impactType);
}
