public List <ObjectPlacementData> Calculate(Quaternion rotationToApplyForStrokeAlignment)
{
if (!ValidateCalculationRequirements())
{
return(new List <ObjectPlacementData>());
}
_objectNodeNetwork.Clear();
_rotationToApplyForStrokeAlignment = rotationToApplyForStrokeAlignment;
CreateSurfaceColliderProjector();
_elementToNewPrefabRotation.Clear();
_allowObjectIntersection = ObjectPlacementSettings.Get().ObjectIntersectionSettings.AllowIntersectionForDecorPaintBrushModeDrag;
int currentObjectIndex = 0;
var objectPlacementDataInstances = new List <ObjectPlacementData>(_workingBrush.MaxNumberOfObjects);
while (currentObjectIndex < _workingBrush.MaxNumberOfObjects)
{
DecorPaintObjectPlacementBrushElement brushElement = _brushElementSpawnChanceTable.PickEntity(UnityEngine.Random.Range(0.0f, 1.0f));
int brushElementIndex = _allValidBrushElements.FindIndex(item => item == brushElement);
++currentObjectIndex;
// No object nodes were created yet?
if (_objectNodeNetwork.NumberOfNodes == 0)
{
// Create the first node at a random position inside the brush circle
Vector3 randomPositionInsideCircle = _workingBrushCircle.GetRandomPointInside();
ObjectSurfaceData objectSurfaceData = CalculateObjectSurfaceData(randomPositionInsideCircle);
MatrixObjectBoxPair matrixObjectBoxPair = CalculateMatrixObjectBoxPair(brushElementIndex, objectSurfaceData);
// We need to know if the normal of the surface on which the object resides lies within the desired slope range
bool passesSlopeTest = DoesObjectSurfacePassSlopeTest(objectSurfaceData, brushElement);
// Note: Even if the slope test is not passed, we will still create an object node. The reason for this is that
// we want to have some kind of continuity in the algorithm. Imagine that the brush circle is large and is
// divided by a large terrain mountain which sits in the middle. If the object generation starts on one side
// of the mountain, the algorithm might never get a chance to go over the other side if the slope condition
// is not satisifed. We want to spread objects as much as possible so even though this object will not be
// placed in the scene, we will still add it to the node network.
_objectNodeNetwork.AddNodeToEnd(matrixObjectBoxPair.ObjectBox, objectSurfaceData);
if (passesSlopeTest && DoesBoxPassObjectIntersectionTest(matrixObjectBoxPair.ObjectBox, brushElement.Prefab.UnityPrefab, matrixObjectBoxPair.ObjectMatrix))
{
objectPlacementDataInstances.Add(new ObjectPlacementData(matrixObjectBoxPair.ObjectMatrix, brushElement.Prefab, brushElement.MustEmbedInSurface));
}
}
else
{
// Are there any node segments available?
if (_objectNodeNetwork.NumberOfSegments != 0)
{
// The first step is to generate a random node index and store references to that node and its immediate neighbour
_objectNodeNetwork.RemoveAllNodesWhichGenerateConcavities(_workingBrushCircle.Plane);
int randomNodeIndex = _objectNodeNetwork.GetRandomNodeIndex();
ObjectNode firstNode = _objectNodeNetwork.GetNodeByIndex(randomNodeIndex);
ObjectNode secondNode = _objectNodeNetwork.GetNodeByIndex(randomNodeIndex + 1);
// Calculate the plane of the segment which unites the 2 nodes. We will also store the
// actual segment and the middle point on the segment. We will use this middle point to
// generate the initial object position.
Segment3D nodeSegment = ObjectNodeNetwork.CalculateSegmentBetweenNodes(firstNode, secondNode);
Vector3 segmentMidPoint = nodeSegment.GetPoint(0.5f);
Plane segmentPlane = ObjectNodeNetwork.CalculateSegmentPlaneNormal(firstNode, secondNode);
OrientedBox firstNodeBox = firstNode.ObjectBox;
OrientedBox secondNodeBox = secondNode.ObjectBox;
// Calculate the furthest point in front of the plane using the corner points of the
// 2 nodes. The idea is to move the new object as much as possible from the bulk of
// objects that have already been generated.
Vector3 furthestPointFromPlane;
List <Vector3> nodeCornerPoints = firstNodeBox.GetCornerPoints();
nodeCornerPoints.AddRange(secondNodeBox.GetCornerPoints());
if (!segmentPlane.GetFurthestPointInFront(nodeCornerPoints, out furthestPointFromPlane))
{
continue;
}
// Use the calculated furthest point from plane and the the existing plane normal to calculate the
// pivot plane. The new object will reside at some distance away from this plane.
Plane pivotPlane = new Plane(segmentPlane.normal, furthestPointFromPlane);
// Calculate the new object transform data. We will use the segment's mid point to generate the
// initial object position.
ObjectSurfaceData objectSurfaceData = CalculateObjectSurfaceData(segmentMidPoint);
MatrixObjectBoxPair matrixObjectBoxPair = CalculateMatrixObjectBoxPair(brushElementIndex, objectSurfaceData);
OrientedBox objectBox = matrixObjectBoxPair.ObjectBox;
// Identify the objects's furthest point behind the plane
Vector3 objectBoxPivotPoint;
List <Vector3> objectBoxCornerPoints = objectBox.GetCornerPoints();
if (!pivotPlane.GetFurthestPointBehind(objectBoxCornerPoints, out objectBoxPivotPoint))
{
continue;
}
// Use the furthest point to move the object in front of the plane and take the distance between objects into account
Vector3 fromPivotPointToCenter = objectBox.Center - objectBoxPivotPoint;
Vector3 projectedPivotPoint = pivotPlane.ProjectPoint(objectBoxPivotPoint);
objectBox.Center = projectedPivotPoint + fromPivotPointToCenter + pivotPlane.normal * _workingBrush.DistanceBetweenObjects;
// Generate the object surface data
objectSurfaceData = CalculateObjectSurfaceData(objectBox.Center);
bool passesSlopeTest = DoesObjectSurfacePassSlopeTest(objectSurfaceData, brushElement);
// Now we need to adjust the orientation and center of the box. If the calculated center
// lies outside the brush circle, we will ignore this node.
AdjustObjectBoxRotationOnSurface(objectBox, objectSurfaceData, brushElement);
AdjustObjectBoxCenterToSitOnSurface(objectBox, objectSurfaceData, brushElement);
if (!_workingBrushCircle.ContainsPoint(_workingBrushCircle.Plane.ProjectPoint(objectBox.Center)))
{
continue;
}
// Recalculate the object matrix using the new box data
TransformMatrix objectMatrix = matrixObjectBoxPair.ObjectMatrix;
objectMatrix.Rotation = objectBox.Rotation;
objectMatrix.Translation = ObjectPositionCalculator.CalculateObjectHierarchyPosition(brushElement.Prefab, objectBox.Center, objectMatrix.Scale, objectBox.Rotation);
// We have been modifying the matrix and box data independently so we will ensure that the box uses the latest data
OrientedBox finalBox = new OrientedBox(objectBox);
finalBox.SetTransformMatrix(objectMatrix);
// If the slope test passed, we will calculate an object placement data instance. Otherwise, we will just insert a new node.
if (passesSlopeTest && DoesBoxPassObjectIntersectionTest(finalBox, brushElement.Prefab.UnityPrefab, objectMatrix))
{
objectPlacementDataInstances.Add(new ObjectPlacementData(objectMatrix, brushElement.Prefab, brushElement.MustEmbedInSurface));
}
_objectNodeNetwork.InsertAfterNode(objectBox, objectSurfaceData, randomNodeIndex);
}
else
{
// When there are no segments available it means we have only one node. We will use this node to generate
// a new one at some distance away from it. First we will store some data that we will need during the entire
// procedure.
ObjectNode pivotNode = _objectNodeNetwork.GetFirstNode();
Vector3 pivotNodeSurfaceTangent = pivotNode.ObjectSurfaceData.GetSurfaceTangentVector();
OrientedBox pivotNodeObjectBox = pivotNode.ObjectBox;
// We will place the new node at some distance away from the first node's face which points
// along the calculated tangent vector. We will call this the pivot face.
BoxFace pivotBoxFace = pivotNodeObjectBox.GetBoxFaceMostAlignedWithNormal(pivotNodeSurfaceTangent);
Plane pivotFacePlane = pivotNodeObjectBox.GetBoxFacePlane(pivotBoxFace);
// Generate the data for the new node in the same position as the first node.
// Note: Although the same position is used, the rotation and scale will differ and they will
// be established by 'CalculateMatrixObjectBoxPair'.
MatrixObjectBoxPair matrixObjectBoxPair = CalculateMatrixObjectBoxPair(brushElementIndex, pivotNode.ObjectSurfaceData);
OrientedBox objectBox = matrixObjectBoxPair.ObjectBox;
// At this point we have to start moving the generated object box to its new positino along the
// tangent vector. We will do this by calculating the furthest box point which lies behind the
// pivot plane and then move the box so that this point resides on that plane. We will call this
// the pivot point.
// Note: We will perform a safety check to see if this point could not be calculated and use the
// closest point in front if necessary. However, this check should not be necessary. Because
// we are placing te object box in the center of the previous box, we can be usre that there
// will always be a point which lies behind the pivot plane.
Vector3 objectBoxPivotPoint;
List <Vector3> objectBoxCornerPoints = objectBox.GetCornerPoints();
if (!pivotFacePlane.GetFurthestPointBehind(objectBoxCornerPoints, out objectBoxPivotPoint) &&
!pivotFacePlane.GetClosestPointInFront(objectBoxCornerPoints, out objectBoxPivotPoint))
{
continue;
}
// Project the pivot point onto the pivot plane. We will also store a vector which goes from the
// original pivot point to the box center. This will allow us to maintain the relationship between
// the projected pivot point and the box center so that the center can be adjusted accordingly.
Vector3 fromPivotPointToCenter = objectBox.Center - objectBoxPivotPoint;
Vector3 projectedPivotPoint = pivotFacePlane.ProjectPoint(objectBoxPivotPoint);
// Adjust the center using the projected pivot point and also take the distance between objects into account
objectBox.Center = projectedPivotPoint + fromPivotPointToCenter + pivotNodeSurfaceTangent * _workingBrush.DistanceBetweenObjects;
// Generate the object surface data at the current box position.
// Note: This is the step which can actually cause objects to intersect a little bit. The surface data is
// calculated by projecting along the brush circle plane normal. If we are placing objects on a terrain
// and the center of the circle lies somewhere at the base of the terrain where the normal points straight
// up, but the center of the box resides somewhere on a clif, the new center might move the box closer
// or even further away from the pivot node. This however, should not be a problem especially if the distance
// between objects is not 0.
ObjectSurfaceData objectSurfaceData = CalculateObjectSurfaceData(objectBox.Center);
bool passesSlopeTest = DoesObjectSurfacePassSlopeTest(objectSurfaceData, brushElement);
// Now we need to adjust the orientation and center of the box. If the calculated center
// lies outside the brush circle, we will ignore this node.
AdjustObjectBoxRotationOnSurface(objectBox, objectSurfaceData, brushElement);
AdjustObjectBoxCenterToSitOnSurface(objectBox, objectSurfaceData, brushElement);
if (!_workingBrushCircle.ContainsPoint(_workingBrushCircle.Plane.ProjectPoint(objectBox.Center)))
{
continue;
}
// Recalculate the object matrix using the new box data
TransformMatrix objectMatrix = matrixObjectBoxPair.ObjectMatrix;
objectMatrix.Rotation = objectBox.Rotation;
objectMatrix.Translation = ObjectPositionCalculator.CalculateObjectHierarchyPosition(brushElement.Prefab, objectBox.Center, objectMatrix.Scale, objectBox.Rotation);
// We have been modifying the matrix and box data independently so we will ensure that the box uses the latest data
OrientedBox finalBox = new OrientedBox(objectBox);
finalBox.SetTransformMatrix(objectMatrix);
// If the slope test passed, we will calculate an object placement data instance. Otherwise, we will just insert a new node.
if (passesSlopeTest && DoesBoxPassObjectIntersectionTest(finalBox, brushElement.Prefab.UnityPrefab, objectMatrix))
{
objectPlacementDataInstances.Add(new ObjectPlacementData(objectMatrix, brushElement.Prefab, brushElement.MustEmbedInSurface));
}
_objectNodeNetwork.InsertAfterNode(objectBox, objectSurfaceData, 0);
}
}
}
// Adjust the prefab rotations for the next time the function is called
if (_elementToNewPrefabRotation.Count != 0)
{
foreach (var prefabRotationPair in _elementToNewPrefabRotation)
{
DecorPaintObjectPlacementBrushElement brushElement = prefabRotationPair.Key;
if (_elementToCurrentPrefabRotation.ContainsKey(brushElement))
{
_elementToCurrentPrefabRotation[brushElement] = prefabRotationPair.Value;
}
}
}
return(objectPlacementDataInstances);
}