Silverlight C# 游戏开发：L5 3D基本的灯光

我们在设计和开发3D的时候最常用的就是灯光，它有的时候比摄像机还要重要，一些花哨漂亮的表现主要通过灯光实现，相比场景中只有一个的主要摄像机以外，灯光的类型和内容更加丰富，今天暂用小段时间一起研究一下Silverlight3D当中的灯光。下图是具体实现的预览效果：

在开始之前，需要了解一下基本的灯光类型，Balder3D里有三种灯光类型，分别是OmniLight、ViewLight、DirectionalLight，如果玩过3Dmax的朋友应该是相当的熟悉，这些光的表现形式组合构成了游戏世界的绚丽多彩，没有光的世界大家可以通过最后程序实验一下，看看会如何呢。

OmniLight:也称泛光灯或者点光，比较清楚理解，它就是一个点发出的光源

ViewLight:有了方向和目标，除了这个方向方位之内的都不会被照亮

DirectionalLight：是方向光，它是一个方向的照亮

具体内容可以参考下面的图片说明来理解他们，图片截取自3DMAX，资源来源于网络。

有一个好看的灯光，固然重要，但是我们要先学会如何控制它们，今次的代码比较多，涉及到了界面的操作，我将Lesson05代码全部贴上，我的建议还是下载源文件看比较好一些：）

首先新建Lesson05这个控件，XAML代码如下：（下述代码使用Blend工具制作生成）

Lesson05.xaml

Lesson05.xaml.cs代码如下，具体实现请参照Lesson04的讲述

Lesson05.xaml.cs

using System;
using System.Windows.Threading;
using System.Windows.Controls;
using System.Windows.Media;
using Balder.Math;
using Balder.Objects.Geometries;
using Balder.View;
using Balder.Lighting;
using Balder.Execution;

namespace Balder_Studio
{
    public partial class Lesson05 : UserControl
    {
        //选择的灯光
        Light _SelectedLight = null;
        public Lesson05()
        {
            InitializeComponent();
            slider_axis_x.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_axis_ValueChanged);
            slider_axis_y.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_axis_ValueChanged);
            slider_axis_z.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_axis_ValueChanged);
            slider_Strength.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_axis_ValueChanged);

            slider_axis_x1.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_Offset_ValueChanged);
            slider_axis_y1.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_Offset_ValueChanged);
            slider_axis_z1.ValueChanged += new System.Windows.RoutedPropertyChangedEventHandler<double>(slider_Offset_ValueChanged);


            OmniLight _OmniLight = new OmniLight();
            ViewLight _ViewLight = new ViewLight();
            DirectionalLight _DirectionalLight = new DirectionalLight() {Direction=new Coordinate(-1,-1,0) };
            //设定在同一个默认位置
            _OmniLight.Position = _ViewLight.Position = _DirectionalLight.Position = new Coordinate(0, 0, 0);
            //最开始的时候都不会亮
            _OmniLight.IsEnabled = _ViewLight.IsEnabled = _DirectionalLight.IsEnabled = false;

            LightType.Items.Add(new TextBlock() { Text = "点光源", Tag = _OmniLight });
            LightType.Items.Add(new TextBlock() { Text = "聚光源", Tag = _ViewLight });
            LightType.Items.Add(new TextBlock() { Text = "方向光", Tag = _DirectionalLight });
            LightType.SelectedIndex = 0;
            LightType.SelectionChanged += new SelectionChangedEventHandler(LightType_SelectionChanged);

            #region L1 - L4的代码
            //L1
            Game game = new Game() { Width = 600, Height = 400 };
            game.Camera = new Camera();
            game.Camera.Position = new Coordinate(100, 120, 150);
            game.Camera.Target = new Coordinate(0, 0, 0);
            #endregion
            game.Children.Add(_OmniLight);
            _OmniLight.IsEnabled = true;
            _SelectedLight = _OmniLight;
            game.Children.Add(_ViewLight);
            game.Children.Add(_DirectionalLight);
            #region L1 - L4的代码
            //L3
            Game_Axis axis_x = new Game_Axis(new Vertex(-300, 0, 0), new Vertex(300, 0, 0), Colors.Red);
            Game_Axis axis_y = new Game_Axis(new Vertex(0, -300, 0), new Vertex(0, 300, 0), Colors.Blue);
            Game_Axis axis_z = new Game_Axis(new Vertex(0, 0, -300), new Vertex(0, 0, 300), Colors.Green);
            //L4
            Balder.Objects.Geometries.Geometry group = new Balder.Objects.Geometries.Geometry() { Name = "MeshGroup" };
            group.InteractionEnabled = true;
            group.Children.Add(axis_x);
            group.Children.Add(axis_y);
            group.Children.Add(axis_z);
            //L2
            Mesh Teapot = new Mesh();
            Teapot.Position = new Coordinate(0, 0, 0);

            Teapot.AssetName = new Uri("/Balder_Studio;component/Res/teapot.ase", UriKind.Relative);
            //L4
            group.Children.Add(Teapot);
            group.Children.Add(new Box() { Dimension = new Coordinate(10, 20, 30), Position = new Coordinate(100, 10, 0), Name = "MyBox" });
            group.Children.Add(new Box() { Dimension = new Coordinate(10, 30, 10), Position = new Coordinate(10, 10, -100) });
            game.Children.Add(group);

            LayoutRoot.Children.Add(game);
            #endregion

        }
        #region 控制灯光的界面事件
        void LightType_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            //选择一个新的光源之时
            if (_SelectedLight != null)
                _SelectedLight.IsEnabled = false;
            _SelectedLight = ((LightType.SelectedItem as TextBlock).Tag as Light);
            _SelectedLight.IsEnabled = true;
            if (_SelectedLight is OmniLight)
                LightExSetting.Visibility = System.Windows.Visibility.Collapsed;
            else
                LightExSetting.Visibility = System.Windows.Visibility.Visible;

        }

        void slider_axis_ValueChanged(object sender, System.Windows.RoutedPropertyChangedEventArgs<double> e)
        {
            axis_z.Text = ((int)slider_axis_z.Value).ToString();
            _SelectedLight.Position.Z = slider_axis_z.Value;
            axis_y.Text = ((int)slider_axis_y.Value).ToString();
            _SelectedLight.Position.Y = slider_axis_y.Value;
            axis_x.Text = ((int)slider_axis_x.Value).ToString();
            _SelectedLight.Position.X = slider_axis_x.Value;
            StrengthText.Text = slider_Strength.Value.ToString();
            _SelectedLight.Strength = slider_Strength.Value;
        }
        void slider_Offset_ValueChanged(object sender, System.Windows.RoutedPropertyChangedEventArgs<double> e)
        {
            axis_z1.Text = ((int)slider_axis_z1.Value).ToString();
            axis_y1.Text = ((int)slider_axis_y1.Value).ToString();
            axis_x1.Text = ((int)slider_axis_x1.Value).ToString();

            if (_SelectedLight is ViewLight)
            {
                var l = _SelectedLight as ViewLight;
                l.XAngleOffset = slider_axis_x1.Value;
                l.YAngleOffset = slider_axis_y1.Value;
                l.ZAngleOffset = slider_axis_z1.Value;
            }
            else
            {
                var l = _SelectedLight as DirectionalLight;
                var X = slider_axis_x1.Value / slider_axis_x1.Maximum;
                var Y = slider_axis_y1.Value / slider_axis_y1.Maximum;
                var Z = slider_axis_z1.Value / slider_axis_z1.Maximum;
                l.Direction = new Coordinate(X, Y, Z);
            }
        }

        #endregion
    }
}

我在其中加入了一些注释，希望有用：）细心的朋友可能会发现，这次没有讲解有关灯光颜色的问题，下次我专门写一篇有关颜色的部分，这样看起来更加直观，期望各位能够对Silverlight3D产生一些兴趣，加入这个开发方向上来。

好吧下一步让我们看看运行效果，同时附送本文章的源代码点击这里下载。

工程中如果缺少Balder.dll请在这里快速下载：SL4_Balder.rar

推荐Silverlight游戏开发博客：深蓝色右手

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原文地址：https://www.cnblogs.com/nowpaper/p/1886439.html