[英]How to select topmost element in a helix-toolkit sharpDX viewport?
我正在使用helix-toolkit庫的sharpDX分支來處理我大學的一個項目( HelixToolKit庫 )
目前,我正在尋找一種正確選擇視口中元素的方法。
我在helixtoolkit庫的源代碼中找到了一個有用的示例: GitHub上的示例代碼
public class MyLineGeometryModel3D : LineGeometryModel3D
{
private Color? initialColor = null;
public override bool HitTest(Ray rayWS, ref List<HitTestResult> hits)
{
if (initialColor == null)
{
initialColor = this.Color;
}
var result = base.HitTest(rayWS, ref hits);
var pressedMouseButtons = Viewport3DX.GetPressedMouseButtons();
if (pressedMouseButtons == 0 || pressedMouseButtons.HasFlag(MouseButtons.Left))
{
this.Color = result ? Color.Red : this.initialColor.Value;
}
return result;
}
}
我設法使它在我的應用程序中運行。 但是,不僅選擇了最上面的元素,還選擇了所有與射線相交的元素。 可能需要某種處理函數來突出顯示具有最短距離的元素?
我正在為此檢查一些標准WPF解決方案,並且它們經常使用事件處理程序。 (例如,WPF中的3D命中測試 )
private void m_viewport3d_MouseDown(object sender, MouseButtonEventArgs e)
{
Point mousePos = e.GetPosition(m_viewport3d);
PointHitTestParameters hitParams = new PointHitTestParameters(mousePos);
HitTestResult result = VisualTreeHelper.HitTest(m_viewport3d, mousePos);
RayMeshGeometry3DHitTestResult rayMeshResult = result as RayMeshGeometry3DHitTestResult;
if (rayMeshResult != null)
{
MeshGeometry3D mesh = new MeshGeometry3D();
mesh.Positions.Add(rayMeshResult.MeshHit.Positions[rayMeshResult.VertexIndex1]);
mesh.Positions.Add(rayMeshResult.MeshHit.Positions[rayMeshResult.VertexIndex2]);
mesh.Positions.Add(rayMeshResult.MeshHit.Positions[rayMeshResult.VertexIndex3]);
mesh.TriangleIndices.Add(0);
mesh.TriangleIndices.Add(1);
mesh.TriangleIndices.Add(2);
GeometryModel3D marker = new GeometryModel3D(mesh, new DiffuseMaterial(Brushes.Blue));
//...add marker to the scene...
}
}
使用事件處理程序是否是明智的解決方案? 如果是的話,如何獲取光線元素以在事件處理程序中調用HitTest函數?
使用視口方法FindNearest:
private void OnMouseDown(object sender, MouseButtonEventArgs e)
{
Viewport3DX vp = e.Source as Viewport3DX;
Point3D p;
Vector3D v;
Model3D m;
if (vp.FindNearest(e.GetPosition(vp), out p, out v, out m))
{
//Do something with the found object
}
}
因此,我實際上自己找到了一個解決方案,這可能並不完美。 但這也許對某人有用。
private void ViewPort3D_OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Ray ray = this.ViewPort3D.UnProject(new Vector2((float)e.GetPosition(ViewPort3D).X, (float)e.GetPosition(ViewPort3D).Y));
var hits = new List<HitTestResult>();
// dictionary for connecting the id of the specific element and its distance
var hitElements = new Dictionary<int, double>();
// loop over all MeshGeometryModel3D elements
foreach (var geometry in Geometrys)
{
var isHit = geometry.Model3D.HitTest(ray, ref hits);
if (isHit)
{
hitElements.Add(geometry.Id, hits[hits.Count - 1].Distance);
}
}
if (hits.Count > 0)
{
double minDistance = hitElements.First().Value;
int id_of_hit_element = hitElements.First().Key;
foreach (var hit in hitElements)
{
if (hit.Value < minDistance)
{
minDistance = hit.Value;
id_of_hit_element = hit.Key;
}
}
var topElement = Geometrys.Find(geometry => geometry.Id == id_of_hit_element);
// do something with top element
}
}
PS不是一名計算機科學家,而是一名土木工程專業的學生,他正在嘗試最好的xD
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