Release v0.9.6

2026-07-31 19:29:07 +03:00
parent 3602e87e0c
commit 8e6b90a10e
264 changed files with 12411 additions and 2 deletions
@@ -0,0 +1,103 @@
+// Licensed under the Non-Profit Open Software License version 3.0
+
+// Variables
+uint ErosionParticleCount;
+uint ErosionMaxLifeTime;
+float ErosionInertia;
+float ErosionParticleStartSpeed;
+float ErosionParticleStartWater;
+float ErosionSedimentCapacityFactor;
+float ErosionMinSedimentCapacity;
+float ErosionSpeed;
+float ErosionEvaporateSpeed;
+float ErosionGravity;
+float ErosionDepositSpeed;
+
+// Kernel
+[numthreads(32,1,1)]
+void HydraulicErosion (uint3 id : SV_DispatchThreadID)
+{
+    if(id.x < ErosionParticleCount){ // Keep in bounds
+        float randomNormalizedX = Random(id.x);
+        float randomNormalizedY = Random(id.x + HeightMapResolution * randomNormalizedX);
+        
+        float2 pos = float2(
+            randomNormalizedX * HeightMapResolution,
+            randomNormalizedY * HeightMapResolution
+        );
+        
+        // Particle values
+        float2 dir = float2(0,0);
+        float speed = ErosionParticleStartSpeed;
+        float water = ErosionParticleStartWater;
+        float sediment = 0;
+    
+        for(uint lifeTime = 0; lifeTime < ErosionMaxLifeTime; lifeTime++){
+            // Calculate texture coords
+            uint2 coord = uint2(
+                (uint) pos.x,
+                (uint) pos.y
+            );
+            
+            int index = PosToIndex(coord, HeightMapResolution);
+            
+            // Calculate cell offset
+            float2 cellOffset = float2(
+                pos.x - float(coord.x),
+                pos.y - float(coord.y)
+            );
+            
+            // Calculate interpolated gradient and height
+            float3 heightAndGradient = CalculateGradientAndHeight(pos, HeightMapResolution, HeightBuffer);
+            
+            // Update the droplet's direction and position (move position 1 unit regardless of speed)
+            dir.x = (dir.x * ErosionInertia - heightAndGradient.x * (1 - ErosionInertia));
+            dir.y = (dir.y * ErosionInertia - heightAndGradient.y * (1 - ErosionInertia));
+                 
+            // Normalize dir
+            dir = Normalize2D(dir);
+            
+            // Add to position
+            pos += dir;
+            
+            // Header guard to check wheter particle is still inside texture and moving
+            if((dir.x == 0 && dir.y == 0) || pos.x <= 0 || pos.y <= 0 || pos.x >= float(HeightMapResolution - 2) || pos.y >= float(HeightMapResolution - 2)){ break; }
+            
+            // Calculate new height and deltaHeight
+            float height = CalculateGradientAndHeight(pos, HeightMapResolution, HeightBuffer).z;
+            float deltaHeight = height - heightAndGradient.z;
+            
+            // Calculate the droplet's sediment capacity (higher when moving fast down a slope and contains lots of water)
+            float sedimentCapacity = max(-deltaHeight, ErosionMinSedimentCapacity) * speed * water * ErosionSedimentCapacityFactor;
+            
+            // If carrying more sediment than capacity, or if flowing uphill:
+            if (sediment > sedimentCapacity || deltaHeight > 0) {
+                // If moving uphill (deltaHeight > 0) try fill up to the current height, otherwise deposit a fraction of the excess sediment
+                float amountToDeposit = (deltaHeight > 0) ? 
+                    min(deltaHeight, sediment) :
+                    (sediment - sedimentCapacity) * ErosionDepositSpeed;
+                
+                // Remove deposited sediment
+                sediment -= amountToDeposit;
+                
+                // Add the sediment to the four nodes of the current cell using bilinear interpolation
+                 AddToBuffer(index, HeightMapResolution, cellOffset, amountToDeposit, HeightBuffer);
+            }
+            else {
+                // Erode a fraction of the droplet's current carry capacity.
+                // Clamp the erosion to the change in height so that it doesn't dig a hole in the terrain behind the droplet
+                float amountToErode = min((sedimentCapacity - sediment) * ErosionSpeed, -deltaHeight);
+                
+                // Remove erosion amount from heightmap
+                AddToBuffer(index, HeightMapResolution, cellOffset, -amountToErode, HeightBuffer);
+                
+                // Add eroded amount to sediment currently carried
+                sediment += amountToErode;
+            }
+    
+            // Update droplet's speed and water content
+            speed = sqrt (max(0,speed * speed + deltaHeight * ErosionGravity));
+            water *= (1 - ErosionEvaporateSpeed);
+        }
+    }
+}