change the camera field of view dynamically

Question

Hello

I am using helix toolkit, to parse and render Gcode (I think I can do this with direct x)

Buen anyway, I have a slider, that supposedly change the field of view (simulating zoom)

but it doesn't want to change anything

    <TextBlock
        Margin="5,5,0,0"
        Text="Field of view" />
    <Slider
        Grid.Column="1"
        Maximum="200"
        Minimum="10"
        Value="{x:Bind _3DViwerViewModel.FieldOfView, Mode=TwoWay}" />
</Grid>


<hx:Viewport3DX
    Grid.Row="1"
    Grid.Column="1"
    BackgroundColor="#89FFFFFF"
    Camera="{x:Bind _3DViwerViewModel.Camera, Mode=TwoWay}"
    EffectsManager="{x:Bind _3DViwerViewModel.EffectsManager}"
    FXAALevel="High"
    FixedRotationPoint="{x:Bind _3DViwerViewModel.ModelCentroid}"
    FixedRotationPointEnabled="True"
    ShowViewCube="False"
    ZoomAroundMouseDownPoint="True">

    <!--  Add lighting  -->
    <hx:DirectionalLight3D
        Direction="{x:Bind _3DViwerViewModel.Camera.LookDirection}"
        Color="#6A3685" />

    <!--  Render main content  -->
    <hx:LineGeometryModel3D
        Geometry="{x:Bind _3DViwerViewModel.Root}"
        Thickness="1.0"
        Color="#2D0C3E" />

    <!--  Optional axis  -->
    <hx:LineGeometryModel3D
        Geometry="{x:Bind _3DViwerViewModel.Axis}"
        IsRendering="{x:Bind _3DViwerViewModel.ShowAxis}"
        Thickness="1.5"
        Color="#2E9025" />
</hx:Viewport3DX>

        [ObservableProperty]
        private double fieldOfView = 45;

        // Camera for 3D visualization
        public PerspectiveCamera Camera { get; set; } = new PerspectiveCamera {
            Position = new Vector3(0, 0, 100),
            LookDirection = new Vector3(0, 0, -100),
            UpDirection = new Vector3(0, 1, 0),
            FieldOfView = 45,
        };

        // Rendering effects manager
        public DefaultEffectsManager EffectsManager { get; } = new DefaultEffectsManager();

        // Main 3D content (e.g., parsed G-code lines)
        public LineGeometry3D Root { get; }

        // Optional Axis
        public LineGeometry3D Axis { get; } = GenerateGridLines();

        public Vector3 ModelCentroid { get; } = new Vector3(0, 0, 0);

        public bool ShowAxis { get; set; } = true;

        public _3DViwerViewModel(GcodeItem gcodeContent) {
            FileContent = File.Exists(gcodeContent.FilePath)
                ? File.ReadAllText(gcodeContent.FilePath)
                : string.Empty;

            Root = GenerateGcodeGeometry(FileContent);
        }

        private LineGeometry3D GenerateGcodeGeometry(string FileContent) {
            var builder = new LineBuilder();
            var currentPosition = new Vector3(0, 0, 0);

            foreach(var line in FileContent.Split(Environment.NewLine)) {
                try {
                    if(line.TrimStart().StartsWith(";")) // Skip comments
                    {
                        continue;
                    }

                    if(line.StartsWith("G1")) // Parse movement commands
                    {
                        var parts = line.Split(' ');
                        float x = currentPosition.X;
                        float y = currentPosition.Y;
                        float z = currentPosition.Z;

                        foreach(var part in parts) {
                            if(part.StartsWith("X")) {
                                x = float.Parse(part.Substring(1));
                            }

                            if(part.StartsWith("Y")) {
                                y = float.Parse(part.Substring(1));
                            }

                            if(part.StartsWith("Z")) {
                                z = float.Parse(part.Substring(1));
                            }
                        }

                        var newPosition = new Vector3(x, y, z);
                        builder.AddLine(currentPosition, newPosition);
                        currentPosition = newPosition;
                    }
                } catch(Exception ex) {
                    Debug.WriteLine($"Error parsing line: {line}. Exception: {ex.Message}");
                }
            }

            return builder.ToLineGeometry3D();
        }

        private static LineGeometry3D GenerateGridLines() {
            var builder = new LineBuilder();

            // Create horizontal and vertical grid lines
            for(float i = -10; i <= 10; i += 1.0f) {
                // Horizontal lines
                builder.AddLine(new Vector3(-10, i, 0), new Vector3(10, i, 0));
                // Vertical lines
                builder.AddLine(new Vector3(i, -10, 0), new Vector3(i, 10, 0));
            }

            return builder.ToLineGeometry3D();
        }

        partial void OnFieldOfViewChanged(double value) {

            Debug.WriteLine($"FieldOfView changed to: {value}");
            Camera.FieldOfView = value; 
        }
    }
}