Optimize terrain heightmap decoding to use shared code

This commit is contained in:
Wojtek Figat
2025-07-04 11:31:27 +02:00
parent 4b10d7057a
commit 7abed93972
3 changed files with 24 additions and 27 deletions

View File

@@ -286,7 +286,7 @@ void ShaderGenerator::ProcessGroupMath(Box* box, Node* node, Value& value)
case 29:
{
Value inXY = tryGetValue(node->GetBox(0), Value::Zero).AsFloat2();
value = writeLocal(ValueType::Float3, String::Format(TEXT("float3({0}, sqrt(saturate(1.0 - dot({0}.xy, {0}.xy))))"), inXY.Value), node);
value = writeLocal(ValueType::Float3, String::Format(TEXT("float3({0}, sqrt(saturate(1.0 - dot({0}, {0}))))"), inXY.Value), node);
break;
}
// Mad

View File

@@ -5,28 +5,30 @@
#include "./Flax/Common.hlsl"
float DecodeHeightmapHeight(float4 value)
{
return (float)((int)(value.x * 255.0) + ((int)(value.y * 255) << 8)) / 65535.0;
}
float3 DecodeHeightmapNormal(float4 value, out bool isHole)
{
isHole = (value.b + value.a) >= 1.9f;
float2 normalTemp = float2(value.b, value.a) * 2.0f - 1.0f;
float3 normal = float3(normalTemp.x, sqrt(1.0 - saturate(dot(normalTemp, normalTemp))), normalTemp.y);
return normalize(normal);
}
float SampleHeightmap(Texture2D<float4> heightmap, float2 uv, float mipOffset = 0.0f)
{
// Sample heightmap
float4 value = heightmap.SampleLevel(SamplerPointClamp, uv, mipOffset);
// Decode heightmap
float height = (float)((int)(value.x * 255.0) + ((int)(value.y * 255) << 8)) / 65535.0;
return height;
return DecodeHeightmapHeight(value);
}
float SampleHeightmap(Texture2D<float4> heightmap, float2 uv, out float3 normal, out bool isHole, float mipOffset = 0.0f)
{
// Sample heightmap
float4 value = heightmap.SampleLevel(SamplerPointClamp, uv, mipOffset);
// Decode heightmap
float height = (float)((int)(value.x * 255.0) + ((int)(value.y * 255) << 8)) / 65535.0;
float2 normalTemp = float2(value.b, value.a) * 2.0f - 1.0f;
normal = float3(normalTemp.x, sqrt(1.0 - saturate(dot(normalTemp, normalTemp))), normalTemp.y);
isHole = (value.b + value.a) >= 1.9f;
normal = normalize(normal);
return height;
normal = DecodeHeightmapNormal(value, isHole);
return DecodeHeightmapHeight(value);
}
float3 SampleHeightmap(Texture2D<float4> heightmap, float3 localPosition, float4 localToUV, out float3 normal, out bool isHole, float mipOffset = 0.0f)
@@ -36,12 +38,9 @@ float3 SampleHeightmap(Texture2D<float4> heightmap, float3 localPosition, float4
float4 value = heightmap.SampleLevel(SamplerPointClamp, uv, mipOffset);
// Decode heightmap
isHole = (value.b + value.a) >= 1.9f;
float height = (float)((int)(value.x * 255.0) + ((int)(value.y * 255) << 8)) / 65535.0;
normal = DecodeHeightmapNormal(value, isHole);
float height = DecodeHeightmapHeight(value);;
float3 position = float3(localPosition.x, height, localPosition.z);
float2 normalTemp = float2(value.b, value.a) * 2.0f - 1.0f;
normal = float3(normalTemp.x, sqrt(1.0 - saturate(dot(normalTemp, normalTemp))), normalTemp.y);
normal = normalize(normal);
// UVs outside the heightmap are empty
isHole = isHole || any(uv < 0.0f) || any(uv > 1.0f);