Creating a 3D Model and Shader System in C#

One of the easiest ways to give your video game a graphical uplift is by adding in some cool shaders. Shaders essentially change the appearance of a 3D model when it's drawn on the screen, and can make it a solid color, look like glass, or even glow! This only scratches the surface of the possibilities, too.

Using the Bridge pattern allows a 3D model to use any shader available, creating an exponential explosion of combinations and possibilities.

We won't be going over actual shader work in this demo, since it would be a little outside the scope of the lesson, but we can take a look at how such a system would be structured to allow maximum flexibility.

Shader Implementor:

public interface Shader
{
   // Abstract operation needing to be fulfilled:
   void Render(Model model);
}

Model Abstraction:

public abstract class Model
{
   // Implementor Reference:
   protected Shader shader;
   
   /* 
       In a real scenario, 
       we'd want some triangle data
       and some vert data.
   */

   public Model(Shader shader)
   {
       this.shader = shader;
   }

   public void SetShader(Shader shader)
   {
       this.shader = shader;
   }

   // Draws the model to the screen:
   public abstract void Draw();

   // For example purposes, we'll want to show a name:
   public abstract string GetName();
}

Shader Examples:

// Shader example 1: unlit color shader:
public class UnlitColorShader: Shader
{
   // Shader color property:
   string color;

   public UnlitColorShader(string color)
   {
       this.color = color;
   }

   // Implement the render method:
   public void Render(Model model)
   {
       Console.WriteLine("Rendering " + model.GetName() 
       + " with a " + this.color + " color.");
   }
}

// Shader example 2: a glass/transparent shader:
public class GlassShader: Shader
{
   public GlassShader() {}

   // implementing the render method:
   public void Render(Model model)
   {
       Console.WriteLine("Rendering " + model.GetName() 
       + " to look like glass.");
   }
}

Model Examples:

// Model example 1: A basic cube:
public class CubeModel: Model
{
   public CubeModel(Shader shader) : base(shader) {}

   public override void Draw()
   {
       this.shader.Render(this);
   }

   public override string GetName()
   {
       return "Cube";
   }
}

// Model example 2: a monkey:
// (Suzanne, which you might recognize from Blender!)
public class Suzanne: Model
{
   public Suzanne(Shader shader) : base(shader) {}

   public override void Draw()
   {
       this.shader.Render(this);
   }

   public override string GetName()
   {
       return "Suzanne";
   }
}

Demo of the Bridge Pattern

// Demo of the Bridge pattern:
public class Solution
{
   public static void Main(string[] args)
   {
       // Create shaders:
       Shader solidRed = new UnlitColorShader("red");
       Shader solidBlue = new UnlitColorShader("blue");
       Shader glass = new GlassShader();

       // Create the models:
       Model cube = new CubeModel(solidRed);
       Model monkey = new Suzanne(glass);

       // Draw the two models:
       cube.Draw(); // "Rendering Cube with a red color."
       monkey.Draw(); // "Rendering Suzanne to look like glass."

       // Switch out the shader on suzanne:
       monkey.SetShader(solidBlue);

       monkey.Draw(); // "Rendering Suzanne with a blue color."

   }
}