Add ClumpedPositionInput support and bladeUp Vector correction toward…

…s sunlight

Assets/Scripts/GrassSimulation/Core/Inputs/PositionInput.cs

@@ -10,5 +10,12 @@ public abstract class PositionInput : ScriptableObject
  /// <returns>A Vector2 where x:x and y:z with each element in range 0..1</returns>
  /// <param name="id">The index at which the position will be placed in the UvBuffer</param>
  public abstract Vector2 GetPosition(int id);
+
+ /// <summary>
+ /// <para>Gets the number of positions that are consecutively very similar, e.g. in clumped grass.</para>
+ /// </summary>
+ /// <returns>A unsigned int number of the repetition count. If no positions are similar, this should be 1.</returns>
+ /// <remarks>This is needed to avoid clumping billboard grass.</remarks>
+ public abstract uint GetRepetitionCount();
  }
 }

Assets/Scripts/GrassSimulation/Core/Lod/GrassPatch.cs

@@ -35,6 +35,7 @@ public class GrassPatch : Patch
  private bool _applyTransition;
  private Mesh _dummyMesh;
  private Mesh _dummyMeshBillboardCrossed;
+ private Mesh _dummyMeshBillboardScreen;
  private Bounds _inputBounds;
  private Texture2D _normalHeightTexture;
 
@@ -67,8 +68,10 @@ public GrassPatch(SimulationContext ctx, Vector4 patchTexCoord, Bounds bounds) :
  Bounds = boundsCorrected;
  //_boundsVertices = new Bounds.BoundsVertices(bounds);
  _patchTexCoord = patchTexCoord;
+ var maxElementsUsed = Mathf.Max(Ctx.Settings.GetMaxAmountBladesPerPatch(),
+ Ctx.Settings.GetMinAmountBillboardsPerPatch() * 3 * Ctx.PositionInput.GetRepetitionCount());
  _startIndex = Ctx.Random.Next(0,
- (int) (Ctx.Settings.GetSharedBufferLength() - Ctx.Settings.GetMaxAmountBladesPerPatch()));
+ (int) (Ctx.Settings.GetSharedBufferLength() - maxElementsUsed));
  _materialPropertyBlock = new MaterialPropertyBlock();
  _parameterOffsetX = (float) Ctx.Random.NextDouble();
  _parameterOffsetY = (float) Ctx.Random.NextDouble();
@@ -102,6 +105,7 @@ public GrassPatch(SimulationContext ctx, Vector4 patchTexCoord, Bounds bounds) :
  CreateGrassDataTexture();
  CreateDummyMesh();
  CreateDummyMeshBillboardCrossed();
+ CreateDummyMeshBillboardScreen();
  SetupMaterialPropertyBlock();
  }
 
@@ -132,7 +136,7 @@ public void Draw()
  _materialPropertyBlock);
 
  if (_argsBillboardScreen[1] > 0)
- Graphics.DrawMeshInstancedIndirect(_dummyMesh, 0, Ctx.GrassBillboardScreen, Bounds, _argsBillboardScreenBuffer, 0,
+ Graphics.DrawMeshInstancedIndirect(_dummyMeshBillboardScreen, 0, Ctx.GrassBillboardScreen, Bounds, _argsBillboardScreenBuffer, 0,
  _materialPropertyBlock);
  }
 
@@ -284,6 +288,23 @@ private void CreateDummyMeshBillboardCrossed()
  _dummyMeshBillboardCrossed.SetIndices(indices, MeshTopology.Points, 0);
  _dummyMeshBillboardCrossed.RecalculateBounds();
  }
+
+ private void CreateDummyMeshBillboardScreen()
+ {
+ var dummyMeshSize = Ctx.Settings.GetMinAmountBillboardsPerPatch();
+ var dummyVertices = new Vector3[dummyMeshSize];
+ var indices = new int[dummyMeshSize];
+
+ for (var i = 0; i < dummyMeshSize; i++)
+ {
+ dummyVertices[i] = Vector3.zero;
+ indices[i] = i;
+ }
+
+ _dummyMeshBillboardScreen = new Mesh {vertices = dummyVertices};
+ _dummyMeshBillboardScreen.SetIndices(indices, MeshTopology.Points, 0);
+ _dummyMeshBillboardScreen.RecalculateBounds();
+ }
 
  private void SetupMaterialPropertyBlock()
  {

Assets/Scripts/GrassSimulation/Core/Lod/PatchContainer.cs

@@ -49,7 +49,6 @@ public void DrawGizmo()
  protected virtual void UpdatePerFrameData()
  {
  //TODO: Maybe outsource all the computeshader data settings to its own class
- Ctx.GrassSimulationComputeShader.SetBool("BillboardGeneration", false);
  Ctx.GrassGeometry.SetVector("CamPos", Ctx.Camera.transform.position);
  Ctx.GrassGeometry.SetVector("viewDir", Ctx.Camera.transform.forward);
  Ctx.GrassGeometry.SetMatrix("ViewProjMatrix",
@@ -60,13 +59,14 @@ protected virtual void UpdatePerFrameData()
  Ctx.GrassBillboardScreen.SetVector("CamPos", Ctx.Camera.transform.position);
  Ctx.GrassBillboardScreen.SetVector("CamUp", Ctx.Camera.transform.up);
 
+ Ctx.GrassSimulationComputeShader.SetBool("BillboardGeneration", false);
  Ctx.GrassSimulationComputeShader.SetFloat("DeltaTime", Time.deltaTime);
  Ctx.GrassSimulationComputeShader.SetFloat("Time", Time.time);
  Ctx.GrassSimulationComputeShader.SetMatrix("ViewProjMatrix",
  Ctx.Camera.projectionMatrix * Ctx.Camera.worldToCameraMatrix);
  Ctx.GrassSimulationComputeShader.SetFloats("CamPos", Ctx.Camera.transform.position.x,
  Ctx.Camera.transform.position.y, Ctx.Camera.transform.position.z);
-
+ Ctx.GrassSimulationComputeShader.SetVector("SunLight", new Vector4(-Ctx.SunLight.transform.forward.x, -Ctx.SunLight.transform.forward.y, -Ctx.SunLight.transform.forward.z, Ctx.SunLight.intensity));
  Ctx.GrassSimulationComputeShader.SetVector("GravityVec", Ctx.Settings.Gravity);
  }
  }

Assets/Scripts/GrassSimulation/Core/Shaders/Grass.shader

@@ -40,9 +40,10 @@ Shader "GrassSimulation/Grass"
 
  struct UvData { float2 Position; };
 
- //Billboard Generation
+ //Billboard Specific
  uniform float GrassType;
  uniform float BillboardAspect;
+ uniform float RepetitionCount;
 
  //Once
  uniform float BillboardAlphaCutoff;
@@ -137,7 +138,9 @@ Shader "GrassSimulation/Grass"
  OUT.vertexID = vertexID;
  OUT.instanceID = instanceID;
  #ifdef GRASS_BILLBOARD_CROSSED
- OUT.uvLocal = UvBuffer[StartIndex + VertexCount * instanceID + (vertexID % VertexCount)].Position;
+ OUT.uvLocal = UvBuffer[StartIndex + (VertexCount * RepetitionCount) * instanceID + (vertexID % VertexCount) * RepetitionCount].Position;
+ #elif GRASS_BILLBOARD_SCREEN
+ OUT.uvLocal = UvBuffer[StartIndex + (VertexCount * RepetitionCount) * instanceID + (vertexID * RepetitionCount)].Position;
  #else
  OUT.uvLocal = UvBuffer[StartIndex + VertexCount * instanceID + vertexID].Position;
  #endif
@@ -192,12 +195,11 @@ Shader "GrassSimulation/Grass"
  HSOut OUT = (HSOut)0;
 
  float2 uvParameter = float2(ParameterOffsetX, ParameterOffsetY) + IN[0].uvLocal;
- //float2 uvNormalHeight = lerp(NormalHeightUvCorrection.xy, NormalHeightUvCorrection.zw, IN[0].uvLocal);
  float2 uvGlobal = lerp(PatchTexCoord.xy, PatchTexCoord.xy + PatchTexCoord.zw, IN[0].uvLocal);
  float4 normalHeight = NormalHeightTexture.SampleLevel(samplerNormalHeightTexture, uvGlobal, 0);
  float4 SimulationData0 = SimulationTexture0.SampleLevel(samplerSimulationTexture0, IN[0].uvLocal, 0);
  float4 SimulationData1 = SimulationTexture1.SampleLevel(samplerSimulationTexture0, IN[0].uvLocal, 0);
- float4 grassMapData = GrassMapTexture.SampleLevel(samplerParameterTexture, uvGlobal, 0);
+ float4 grassMapData = GrassMapTexture.SampleLevel(samplerNormalHeightTexture, uvGlobal, 0);
 
  OUT.pos = mul(PatchModelMatrix, float4(IN[0].uvLocal.x, normalHeight.w, IN[0].uvLocal.y, 1.0)).xyz;
 
@@ -276,7 +278,7 @@ Shader "GrassSimulation/Grass"
  DSOut OUT = (DSOut)0;
 
  float3 pos = IN[0].pos;
- float3 up = IN[0].bladeUp;
+ float3 up = IN[0].bladeUp; //TODO: Use same correction as in compute shader
  float3 bladeDir = IN[0].bladeDir;
  #ifdef GRASS_GEOMETRY
  float3 v1 = pos + IN[0].v1 * IN[0].transitionFactor;
@@ -307,6 +309,7 @@ Shader "GrassSimulation/Grass"
  float3 i1 = h1 + v * (h2 - h1);
  float3 i2 = i1 + off;
 
+ //TODO: Can be removed?
  #ifdef BILLBOARD_GENERATION
  float widthFactor = 1;
  #elif GRASS_GEOMETRY

Assets/Scripts/GrassSimulation/Core/Shaders/GrassSimulation.compute

@@ -47,6 +47,7 @@ float DeltaTime;
 float Time;
 float4x4 ViewProjMatrix;
 float4 GravityVec;
+float4 SunLight; //Direction towards sun and Influence
 float4 WindData;
 
 float4 LocalToWorldPos(float4 pos){ return mul(PatchModelMatrix, pos); }
@@ -101,7 +102,7 @@ void CalculateBladeDirAndFront(inout float3 bladeUp, in float dirAlpha, out floa
  float3 tmp = normalize(float3(sd, sd + cd, cd)); //arbitrary vector for finding normal vector
  bladeDir = normalize(cross(bladeUp, tmp));
  bladeFront = normalize(cross(bladeUp, bladeDir));
- //bladeUp = normalize(bladeUp + 0.3 * bladeFront);
+ bladeUp = normalize(bladeUp + SunLight.xyz * SunLight.w);
 }
 
 bool IsNAN(float n)
@@ -119,18 +120,22 @@ void SimulationSetup(uint3 id : SV_DispatchThreadID, uint3 gid : SV_GroupID, uin
  //Create all the needed uv coordinates
  float2 uvLocal = float2(id.x/GrassDataResolution, id.y/GrassDataResolution);
  float2 uvGlobal = lerp(PatchTexCoord.xy, PatchTexCoord.xy + PatchTexCoord.zw, uvLocal);
- //float2 uvNormalHeight = lerp(NormalHeightUvCorrection.xy, NormalHeightUvCorrection.zw, uvLocal);
  float2 uvParameter = float2(ParameterOffsetX, ParameterOffsetY) + uvLocal;
 
  //Read all the textures -°O°/
  float4 normalHeight = NormalHeightTexture.SampleLevel(samplerNormalHeightTexture, uvGlobal, 0);
  float4 parameters = ParameterTexture.SampleLevel(samplerParameterTexture, uvParameter, 0);
 
  //Create and name all needed variables
+ float dirAlpha = parameters.w;
+ float3 bladeDir;
+ float3 bladeFront;
  float3 bladeUp = normalize(normalHeight.xyz);
+ float3 bladeNormal = normalize(normalHeight.xyz);
+ CalculateBladeDirAndFront(bladeNormal, dirAlpha, bladeDir, bladeFront);
  float height = parameters.z;
- float3 v2 = bladeUp * height;
- float3 v1 = GetV1(v2, bladeUp, height, 1.0 / height);
+ float3 v2 = bladeNormal * height;
+ float3 v1 = GetV1(v2, bladeNormal, height, 1.0 / height);
 
  AdjustBezierArcLength(v1, v2, height);
 
@@ -146,16 +151,13 @@ void PhysicsMain (uint3 id : SV_DispatchThreadID, uint3 gid : SV_GroupID, uint g
 {
  //Create all the needed uv coordinates
  float2 uvLocal = float2(id.x/GrassDataResolution + 0.5 / GrassDataResolution, id.y/GrassDataResolution + 0.5 / GrassDataResolution);
- //float2 uvNormalHeight = lerp(NormalHeightUvCorrection.xy, NormalHeightUvCorrection.zw, uvLocal);
  float2 uvGlobal = lerp(PatchTexCoord.xy, PatchTexCoord.xy + PatchTexCoord.zw, uvLocal);
- float2 uvCollisionTexture = uvGlobal;
- //uvCollisionTexture.x = 1 - uvCollisionTexture.x;
  float2 uvParameter = float2(ParameterOffsetX, ParameterOffsetY) + uvLocal;
 
  //Read all the textures -°O°/
  float4 normalHeight = NormalHeightTexture.SampleLevel(samplerNormalHeightTexture, uvGlobal, 0);
+ float4 grassMapData = GrassMapTexture.SampleLevel(samplerNormalHeightTexture, uvGlobal, 0);
  float4 parameters = ParameterTexture.SampleLevel(samplerParameterTexture, uvParameter, 0);
- float4 grassMapData = GrassMapTexture.SampleLevel(samplerParameterTexture, uvGlobal, 0);
  //Don't use grassmaps density if we are generating our billboard data
  if (BillboardGeneration) grassMapData.z = 1;
  float4 simulationData0 = SimulationTexture0.Load(id.xy);
@@ -178,11 +180,12 @@ void PhysicsMain (uint3 id : SV_DispatchThreadID, uint3 gid : SV_GroupID, uint g
  float3 localV0 = float3(uvLocal.x, normalHeight.w, uvLocal.y);
  float3 v0 = LocalToWorldPos(localV0).xyz;
  float3 bladeUp = normalize(normalHeight.xyz);
+ float3 bladeNormal = normalize(normalHeight.xyz); //Normal gets altered by negative gravity, so that it grows away
  float3 bladeDir;
  float3 bladeFront;
- CalculateBladeDirAndFront(bladeUp, dirAlpha, bladeDir, bladeFront);
+ CalculateBladeDirAndFront(bladeNormal, dirAlpha, bladeDir, bladeFront);
  float mdt = DeltaTime;//min(DeltaTime, 1.0);
- float3 idleV2 = bladeUp * height;
+ float3 idleV2 = bladeNormal * height;
  float3 v2 = simulationData1.xyz;
  float collisionForce = max(simulationData0.w - (1.0 - bendingFactor) * RecoveryFactor * mdt, 0.0);
 
@@ -210,7 +213,7 @@ void PhysicsMain (uint3 id : SV_DispatchThreadID, uint3 gid : SV_GroupID, uint g
 
  //ValidateV2Tex(v2, v0);
  ValidateV2(v2, bladeUp);
- float3 v1 = GetV1(v2, bladeUp, height, invHeight);
+ float3 v1 = GetV1(v2, bladeNormal, height, invHeight);
  AdjustBezierArcLength(v1, v2, height);
 
  // Collisions
@@ -280,7 +283,7 @@ void PhysicsMain (uint3 id : SV_DispatchThreadID, uint3 gid : SV_GroupID, uint g
  {
  //ValidateV2Tex(v2, v0);
  ValidateV2(v2, bladeUp);
- v1 = GetV1(v2, bladeUp, height, invHeight);
+ v1 = GetV1(v2, bladeNormal, height, invHeight);
  AdjustBezierArcLength(v1, v2, height);
  }
 

Assets/Scripts/GrassSimulation/Core/SimulationContext.cs

@@ -17,6 +17,7 @@ public class SimulationContext : ScriptableObject
  [Header("Requirements")]
  public Transform Transform;
  public Camera Camera;
+ public Light SunLight;
  public ComputeShader GrassSimulationComputeShader;
  public ComputeShader RenderTextureVolumeToSlice;
  public Shader CollisionDepthShader;
@@ -306,8 +307,10 @@ public void Init()
 
  GrassBillboardCrossed.SetTexture("GrassBillboards", BillboardTexturePatchContainer.BillboardTextures);
  GrassBillboardCrossed.SetFloat("BillboardAspect", BillboardTexturePatchContainer.BillboardAspect);
+ GrassBillboardCrossed.SetFloat("RepetitionCount", PositionInput.GetRepetitionCount());
  GrassBillboardScreen.SetTexture("GrassBillboards", BillboardTexturePatchContainer.BillboardTextures);
  GrassBillboardScreen.SetFloat("BillboardAspect", BillboardTexturePatchContainer.BillboardAspect);
+ GrassBillboardScreen.SetFloat("RepetitionCount", PositionInput.GetRepetitionCount());
 
  //Everything is ready.
  IsReady = true;

Assets/Scripts/GrassSimulation/StandardInputs/ClumpedPositionInput.cs

@@ -11,13 +11,10 @@ public class ClumpedPositionInput: PositionInput, IInitializableWithCtx
  private Random _random;
 
  private int _lastId;
- private int _curClumpSize;
  private Vector2 _curPos;
 
  [Range(1, 64)]
- public int ClumpSizeMin = 4;
- [Range(1, 64)]
- public int ClumpSizeMax = 16;
+ public uint ClumpSize = 4;
  public float ClumpRadiusMin = 0.001f;
  public float ClumpRadiusMax = 0.001f;
 
@@ -29,16 +26,17 @@ public void Init(SimulationContext context)
 
  public override Vector2 GetPosition(int id)
  {
- if (_lastId == -1 || id > _lastId + _curClumpSize)
+ if (_lastId == -1 || id > _lastId + ClumpSize)
  {
  _lastId = id;
- _curClumpSize = _random.Next(ClumpSizeMin, ClumpSizeMax);
  _curPos = new Vector2((float) _random.NextDouble(), (float) _random.NextDouble());
  }
  var radius = ClumpRadiusMin + (float) _random.NextDouble() * (ClumpRadiusMax - ClumpRadiusMin);
  var angle = 2 * Mathf.PI * (float) _random.NextDouble();
  var offset = new Vector2(Mathf.Sin(angle), Mathf.Cos(angle)) * radius;
  return _curPos + offset;
  }
+
+ public override uint GetRepetitionCount() { return ClumpSize; }
  }
 }

Assets/Scripts/GrassSimulation/StandardInputs/SimplePositionInput.cs

@@ -18,5 +18,7 @@ public override Vector2 GetPosition(int id)
  {
  return new Vector2((float) _random.NextDouble(), (float) _random.NextDouble());
  }
+
+ public override uint GetRepetitionCount() { return 1; }
  }
 }