Raymarching-Engine-Unity

A fast GPU-accelerated raymarching engine for Unity with support for over 28 primitives (including fractals, n-dimensional objects, volumetric clouds) and set operations (Union, Subtract, Intersect). Includes a custom interface for manipulating shader parameters through the editor.

https://user-images.githubusercontent.com/58925008/155891674-fdb4e1e8-3e80-447b-9439-aec03d8f34eb.mp4

Updates

v002

• The engine now stores the dimensions of the shapes as scriptable objects, to keep multiple instances of same shape persistant across sessions.
• Added support for Ambient Occlussion, Hard/Soft Shadows and various render setting exposed for the users to play around with.
• Download the .unitypackage here.

Rendering the shapes provided

• Attach Raymarcher.cs to the Main Camera and RaymarchRenderer.cs to an empty gameobject.
• Drag the ImageEffectRaymarcher.shader in Shader field of Raymarcher.cs in inspector and direction light to the Sun's transform field.
• Click on Create New Dimensions in the RaymarchRenderer.cs to create a scriptable object to hold the dimesnion data of the shapes.
• You can control the following settings for the raymarching using the Raymarcher component-

  Category	Variable	Description
  General Settings	Shader	Shader used for raymarching.
  	Sun	Directional light in the scene.
  	Loop	Repetition of structures in the raymarching shader.
  Light Settings	Is Lit	Toggle lighting calculations on/off.
  	Is Shadow Hard	Toggle between hard and soft shadows.
  	Is AO	Enable or disable Ambient Occlusion.
  	Light Col	Color of the light.
  	Light Intensity	Intensity of the light.
  	Shadow Intensity	Intensity of shadows.
  	Shadow Min	Minimum shadow distance.
  	Shadow Max	Maximum shadow distance.
  	Shadow Smooth	Smoothness of shadow edges.
  	AO Step	Step size for AO calculation.
  	AO Intensity	Intensity of AO.
  	AO Iteration	Number of iterations for AO calculation.
  Render Settings	Max Steps	Maximum number of steps for raymarching.
  	Max Dist	Maximum distance to raymarch before considering a hit.
  	Surf Dist	Threshold for considering a hit in raymarching.

• You can control the following properties of the individual shapes using the RaymarchRenderer componnent-

  Category	Variable	Description
  Default Inspector	Shape	Shape to be rendered.
  	Operation	Operation to be performed (union, subtraction, intersection).
  	Color	Color of the shape.
  	Create New Dimensions	Button to create new dimenion scriptable object for the shape
  	Dimensions	Scriptable Object holding the shape's dimension data.
  Shape Dimensions	Dimension Props	The dimension properties based on the chosen 4D shape.

Rendering a custom shape

• Append the distance function of the shape in DFs.cginc like

  float sdShape(float3 p, // dimension parameters)	
  {
      // distance function here
  }
  

• Append the distance function created above in GetDist() in the ImageEffectRaymarcher.shader.

  float GetDist(Shape shape, float3 p) {
      switch (shape.shapeIndex) {
      case n:
          return sdShape(float3 p, // dimension parameters);
      }
  }
  

• Add the shape data in the scriptable object ShapeDimensions.cs

  public float shapeDimension = default dimenison
  

• Add the shape in Shape enum in RaymarchRenderer.cs

  public enum Shape {
      // shape name
  };  
  

• Make the dimension array in Helpers.cs to be sent as a compute buffer to the Raymarching shader.

  public static vector12 GetDimensionVectors(int i)
  {
      //dimension vector12 object
  }
  

• Finally make a custom editor for your shape in the PropertiesEditor.cs

  public override void OnInspectorGUI()
  {
      base.OnInspectorGUI();
      RaymarchRenderer renderer = (RaymarchRenderer)target;        
       
      if (GUILayout.Button("Create New Dimensions"))
         renderer.dimensions = CreateShapeDimensionsAsset();
       
      if (renderer.dimensions == null)
         return;
  
      switch (renderer.shape)
      {
          //property editor here
      }
  }