//This method is performing basic collision detection between two models
//Whole model is surrounded by BoundingBox stored in model.Tag info
public static bool GeneralCollisionCheck(Unit unit1, Unit unit2)
{
//Retrieving data about BoundingBox from model.Tag for first model
ModelExtra modelExtra = unit1.currentModel.Model.Tag as ModelExtra;
BoundingSphere originalSphere1 = modelExtra.boundingSphere;
unit1.boundingSphere = XNAUtils.TransformBoundingSphere(originalSphere1, unit1.GetWorldMatrix());
//Doing the same thing for second model
ModelExtra modelExtra1 = unit2.currentModel.Model.Tag as ModelExtra;
BoundingSphere originalSphere2 = modelExtra1.boundingSphere;
unit2.boundingSphere = XNAUtils.TransformBoundingSphere(originalSphere2, unit2.GetWorldMatrix());
//Checking if global bounding Box(surronds whole model) intersects another Box
bool collision = unit1.boundingSphere.Intersects(unit2.boundingSphere);
return collision;
}
//This method performs much more detailed collision check.
//It checks if there is collision for each mesh of model
public static bool DetailedCollisionCheck(Unit unit1, Unit unit2)
{
//first we check if there is general collision between two models
//If method returns false we dont have to perform detailed check
if (!GeneralCollisionCheck(unit1, unit2))
return false;
//Here we are creating BoundingBox for each mesh for model1
Matrix[] model1Transforms = new Matrix[unit1.currentModel.Model.Bones.Count];
unit1.currentModel.Model.CopyAbsoluteBoneTransformsTo(model1Transforms);
BoundingBox[] model1Boxs = new BoundingBox[unit1.currentModel.Model.Meshes.Count];
for (int i = 0; i < unit1.currentModel.Model.Meshes.Count; i++)
{
ModelMesh mesh = unit1.currentModel.Model.Meshes[i];
BoundingSphere origSphere = mesh.BoundingSphere;
BoundingBox origBox = BoundingBox.CreateFromSphere(origSphere);
Matrix trans = model1Transforms[mesh.ParentBone.Index] * unit1.GetWorldMatrix();
BoundingBox transBox = XNAUtils.TransformBoundingBox(origBox, trans);
model1Boxs[i] = transBox;
}
//and here for second model
Matrix[] model2Transforms = new Matrix[unit2.currentModel.Model.Bones.Count];
unit2.currentModel.Model.CopyAbsoluteBoneTransformsTo(model2Transforms);
BoundingBox[] model2Boxs = new BoundingBox[unit2.currentModel.Model.Meshes.Count];
for (int i = 0; i < unit2.currentModel.Model.Meshes.Count; i++)
{
ModelMesh mesh = unit2.currentModel.Model.Meshes[i];
BoundingSphere origSphere = mesh.BoundingSphere;
BoundingBox origBox = BoundingBox.CreateFromSphere(origSphere);
Matrix trans = model2Transforms[mesh.ParentBone.Index] * unit2.GetWorldMatrix();
BoundingBox transBox = XNAUtils.TransformBoundingBox(origBox, trans);
model2Boxs[i] = transBox;
}
bool collision = false;
//Check if any of created before Boxs intersects with another Box
for (int i = 0; i < model1Boxs.Length; i++)
for (int j = 0; j < model2Boxs.Length; j++)
if (BoundingSphere.CreateFromBoundingBox(model1Boxs[i]).Intersects(BoundingSphere.CreateFromBoundingBox(model2Boxs[j])))
return true;
return collision;
}