Embarcadero FireMonkey 3D相机旋转和变焦

Question

我搜索相机旋转和放大FireMonkey 3D的例子。就像使用鼠标左键在场景周围旋转相机并使用鼠标滚轮放大和缩小一样。

任何人都可以帮助我吗？

Answer 1

您可以通过拖动和放大轮来旋转相机。重要的是，在不同的轴上旋转应该全部在不同的嵌套对象上处理，这样旋转计算应该像我们在现实世界中期望的那样相互影响。

Answer 2

下面的表单显示了一个简单的演示，只需保存.fmx和.pas文件并将表单添加到FMX应用程序。关键部分是将相机&嵌套的灯光对象放在Y轴的单独X &上与作为相机目标的DummyObject相连。将X & Y作为单独的虚拟对象使得旋转垂直和水平，这在某些情况下是可取的。您还可以将DummyX DummyY对象合并到一个DummyXY对象中，该对象将提供更真实的世界旋转样式，但取决于您的需求，哪个更适合。

MainForm.pas：

unit MainForm; 

interface 

uses 
    FMX.Forms, FMX.Materials, System.Math.Vectors, FMX.Types3D, FMX.Objects3D, FMX.Controls3D, FMX.Viewport3D, 
    System.Classes, FMX.Types, FMX.Controls, FMX.Layouts, FMX.MaterialSources, System.Types, System.UITypes; 

type 

    TForm1 = class(TForm) 
    Viewport3D: TViewport3D; 
    DummyX: TDummy; 
    DummyObject: TDummy; 
    CameraZ: TCamera; 
    Light1: TLight; 
    LayoutMain: TLayout; 
    DummyY: TDummy; 
    Cone1: TCone; 
    LightMaterialSource1: TLightMaterialSource; 
    procedure Viewport3DMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Single); 
    procedure Viewport3DMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Single); 
    procedure Viewport3DMouseWheel(Sender: TObject; Shift: TShiftState; WheelDelta: Integer; var Handled: Boolean); 
    private 
    FDown: TPointF; 
    procedure DoZoom(aIn: Boolean); 
    public 
    end; 

var 
    Form1: TForm1; 

implementation 

{$R *.fmx} 

const 
    CAMERA_MAX_Z = -2; 
    CAMERA_MIN_Z = -200; 
    ZOOM_STEP = 2; 

procedure TForm1.DoZoom(aIn: Boolean); 
var 
    newZ: Single; 
begin 
    if aIn then 
    newZ := CameraZ.Position.Z + ZOOM_STEP 
    else 
    newZ := CameraZ.Position.Z - ZOOM_STEP; 

    if (newZ < CAMERA_MAX_Z) and (newZ > CAMERA_MIN_Z) then 
    CameraZ.Position.Z := newZ; 
end; 

procedure TForm1.Viewport3DMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Single); 
begin 
    FDown := PointF(X, Y); 
end; 

procedure TForm1.Viewport3DMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Single); 
begin 
    if (ssLeft in Shift) then 
    begin 
    DummyX.RotationAngle.X := DummyX.RotationAngle.X - ((Y - FDown.Y) * 0.3); 
    DummyY.RotationAngle.Y := DummyY.RotationAngle.Y + ((X - FDown.X) * 0.3); 
    FDown := PointF(X, Y); 
    end; 
end; 

procedure TForm1.Viewport3DMouseWheel(Sender: TObject; Shift: TShiftState; WheelDelta: Integer; var Handled: Boolean); 
begin 
    DoZoom(WheelDelta > 0); 
end; 

end. 

MainForm.fmx：

object Form1: TForm1 
    Left = 0 
    Top = 0 
    Caption = 'Form1' 
    ClientHeight = 592 
    ClientWidth = 713 
    FormFactor.Width = 320 
    FormFactor.Height = 480 
    FormFactor.Devices = [Desktop] 
    DesignerMasterStyle = 0 
    object LayoutMain: TLayout 
    Align = Client 
    Size.Width = 713.000000000000000000 
    Size.Height = 592.000000000000000000 
    Size.PlatformDefault = False 
    TabOrder = 2 
    object Viewport3D: TViewport3D 
     Align = Client 
     Camera = CameraZ 
     Size.Width = 713.000000000000000000 
     Size.Height = 592.000000000000000000 
     Size.PlatformDefault = False 
     UsingDesignCamera = False 
     OnMouseDown = Viewport3DMouseDown 
     OnMouseMove = Viewport3DMouseMove 
     OnMouseWheel = Viewport3DMouseWheel 
     object DummyX: TDummy 
     Width = 1.000000000000000000 
     Height = 1.000000000000000000 
     Depth = 1.000000000000000000 
     object DummyY: TDummy 
      Width = 1.000000000000000000 
      Height = 1.000000000000000000 
      Depth = 1.000000000000000000 
      object CameraZ: TCamera 
      AngleOfView = 45.000000000000000000 
      Target = DummyObject 
      Position.Z = -20.000000000000000000 
      Width = 1.000000000000000000 
      Height = 1.000000000000000000 
      Depth = 1.000000000000000000 
      object Light1: TLight 
       Color = claWhite 
       LightType = Directional 
       SpotCutOff = 180.000000000000000000 
       Width = 1.000000000000000000 
       Height = 1.000000000000000000 
       Depth = 1.000000000000000000 
      end 
      end 
     end 
     end 
     object DummyObject: TDummy 
     Width = 1.000000000000000000 
     Height = 1.000000000000000000 
     Depth = 1.000000000000000000 
     object Cone1: TCone 
      Width = 1.000000000000000000 
      Height = 1.000000000000000000 
      Depth = 1.000000000000000000 
      SubdivisionsCap = 3 
      MaterialSource = LightMaterialSource1 
     end 
     end 
    end 
    end 
    object LightMaterialSource1: TLightMaterialSource 
    Diffuse = claWhite 
    Ambient = xFF202020 
    Emissive = claNull 
    Specular = xFF606060 
    Shininess = 30 
    Left = 436 
    Top = 56 
    end 
end 

我把这个从演示的地方，但我需要的伟大工程。应该适用于Delphi XE5以上。