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feat(pbr): improvements to terrain parallax and parallax shadows #982

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Merged
doodlum merged 6 commits into from
Mar 2, 2025
Merged

feat(pbr): improvements to terrain parallax and parallax shadows #982

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7a22c44
feat(pbr): improvements to terrain parallax and parallax shadows
ThePagi Mar 1, 2025
edaed99
style: 🎨 apply clang-format changes
ThePagi Mar 1, 2025
4ebeb46
Update ExtendedMaterials.hlsli
ThePagi Mar 1, 2025
45499e0
Update ExtendedMaterials.hlsli
ThePagi Mar 1, 2025
3f600e4
pow 2 instead of mul 2 parallax shadow
ThePagi Mar 2, 2025
6ec9b55
style: 🎨 apply clang-format changes
ThePagi Mar 2, 2025
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40 changes: 21 additions & 19 deletions features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli
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Original file line number Diff line number Diff line change
Expand Up @@ -51,10 +51,10 @@ namespace ExtendedMaterials
float2 dySize = ddy(texCoordsPerSize);

// Find min of change in u and v across quad: compute du and dv magnitude across quad
float2 dTexCoords = dxSize * dxSize + dySize * dySize;
//float2 dTexCoords = dxSize * dxSize + dySize * dySize;

// Standard mipmapping uses max here
float minTexCoordDelta = max(dTexCoords.x, dTexCoords.y);
float minTexCoordDelta = min(dot(dxSize, dxSize), dot(dySize, dySize));

// Compute the current mip level (* 0.5 is effectively computing a square root before )
float mipLevel = max(0.5 * log2(minTexCoordDelta), 0);
Expand All @@ -72,8 +72,8 @@ namespace ExtendedMaterials

#if defined(LANDSCAPE)
# if defined(TRUE_PBR)
# define HEIGHT_POWER 20
# define HEIGHT_MULT 2
# define HEIGHT_POWER 2
# define HEIGHT_MULT 8
float GetTerrainHeight(PS_INPUT input, float2 coords, float mipLevels[6], DisplacementParams params[6], float blendFactor, float4 w1, float2 w2, out float weights[6])
{
float heightBlend = 1 + blendFactor * HEIGHT_POWER;
Expand Down Expand Up @@ -120,6 +120,10 @@ namespace ExtendedMaterials
total += h * weights[5];
weights[5] *= pow(heightBlend, HEIGHT_MULT * h);
}
[unroll] for (int i = 0; i < 6; i++)
{
weights[i] = pow(weights[i], heightBlend);
}
float wsum = 0;
[unroll] for (int i = 0; i < 6; i++)
{
Expand All @@ -133,8 +137,8 @@ namespace ExtendedMaterials
return total;
}
# else
# define HEIGHT_POWER 20
# define HEIGHT_MULT 2
# define HEIGHT_POWER 2
# define HEIGHT_MULT 8
float GetTerrainHeight(PS_INPUT input, float2 coords, float mipLevels[6], DisplacementParams params[6], float blendFactor, float4 w1, float2 w2, out float weights[6])
{
float heightBlend = 1 + blendFactor * HEIGHT_POWER;
Expand Down Expand Up @@ -175,7 +179,10 @@ namespace ExtendedMaterials
total += h * weights[5];
weights[5] *= pow(heightBlend, HEIGHT_MULT * h);
}

[unroll] for (int i = 0; i < 6; i++)
{
weights[i] = pow(weights[i], heightBlend);
}
float wsum = 0;
[unroll] for (int i = 0; i < 6; i++)
{
Expand Down Expand Up @@ -207,7 +214,6 @@ namespace ExtendedMaterials

float nearBlendToFar = saturate(distance / 2048.0);
#if defined(LANDSCAPE)
// When CPM flag is disabled, will use linear blending as before.
# if defined(TRUE_PBR)
float blendFactor = SharedData::extendedMaterialSettings.EnableHeightBlending ? sqrt(saturate(1 - nearBlendToFar)) : 0;
float4 w1 = lerp(input.LandBlendWeights1, smoothstep(0, 1, input.LandBlendWeights1), blendFactor);
Expand All @@ -230,7 +236,7 @@ namespace ExtendedMaterials

#if defined(LANDSCAPE)
if (nearBlendToFar < 1.0) {
uint numSteps = uint((max(4, scale * 8) * (1.0 - nearBlendToFar)) + 0.5);
uint numSteps = uint((max(6, scale * 8) * (1.0 - nearBlendToFar)) + 0.5);
numSteps = clamp((numSteps + 3) & ~0x03, 4, max(8, scale * 8));
#else
# if defined(TRUE_PBR)
Expand Down Expand Up @@ -372,12 +378,6 @@ namespace ExtendedMaterials
return coords;
}

#if defined(TRUE_PBR)
static const float shadowIntensity = 2.0;
#else
static const float shadowIntensity = 2.0;
#endif

// https://advances.realtimerendering.com/s2006/Tatarchuk-POM.pdf
// Cheap method of creating shadows using height for a given light source
float GetParallaxSoftShadowMultiplier(float2 coords, float mipLevel, float3 L, float sh0, Texture2D<float4> tex, SamplerState texSampler, uint channel, float quality, float noise, DisplacementParams params)
Expand All @@ -394,7 +394,7 @@ namespace ExtendedMaterials
sh.z = AdjustDisplacementNormalized(tex.SampleLevel(texSampler, coords + rayDir * multipliers.z, mipLevel)[channel], params);
if (quality > 0.75)
sh.w = AdjustDisplacementNormalized(tex.SampleLevel(texSampler, coords + rayDir * multipliers.w, mipLevel)[channel], params);
return 1.0 - saturate(dot(max(0, sh - sh0), 1.0) * shadowIntensity) * quality;
return pow(1.0 - saturate(dot(max(0, sh - sh0), 1.0)) * quality, 2.0);
}
return 1.0;
}
Expand All @@ -403,13 +403,15 @@ namespace ExtendedMaterials
float GetParallaxSoftShadowMultiplierTerrain(PS_INPUT input, float2 coords, float mipLevel[6], float3 L, float sh0, float quality, float noise, DisplacementParams params[6])
{
if (quality > 0.0) {
float2 rayDir = L.xy * 0.1;
float4 multipliers = rcp((float4(1, 2, 3, 4) + noise));
float4 sh;
float heights[6] = { 0, 0, 0, 0, 0, 0 };
float2 rayDir = L.xy * 0.1;
# if defined(TRUE_PBR)
float scale = max(params[0].HeightScale * input.LandBlendWeights1.x, max(params[1].HeightScale * input.LandBlendWeights1.y, max(params[2].HeightScale * input.LandBlendWeights1.z,
max(params[3].HeightScale * input.LandBlendWeights1.w, max(params[4].HeightScale * input.LandBlendWeights2.x, params[5].HeightScale * input.LandBlendWeights2.y)))));
if (scale < 0.01)
return 1.0;
rayDir *= scale;
sh = GetTerrainHeight(input, coords + rayDir * multipliers.x, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
if (quality > 0.25)
Expand All @@ -418,7 +420,7 @@ namespace ExtendedMaterials
sh.z = GetTerrainHeight(input, coords + rayDir * multipliers.z, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
if (quality > 0.75)
sh.w = GetTerrainHeight(input, coords + rayDir * multipliers.w, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
return 1.0 - saturate(dot(max(0, sh - sh0), 1.0) * shadowIntensity) * quality;
return pow(1.0 - saturate(dot(max(0, sh - sh0) / scale, 1.0)) * quality, 2.0);
# else
sh = GetTerrainHeight(input, coords + rayDir * multipliers.x, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
if (quality > 0.25)
Expand All @@ -427,7 +429,7 @@ namespace ExtendedMaterials
sh.z = GetTerrainHeight(input, coords + rayDir * multipliers.z, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
if (quality > 0.75)
sh.w = GetTerrainHeight(input, coords + rayDir * multipliers.w, mipLevel, params, quality, input.LandBlendWeights1, input.LandBlendWeights2.xy, heights);
return 1.0 - saturate(dot(max(0, sh - sh0), 1.0) * shadowIntensity) * quality;
return pow(1.0 - saturate(dot(max(0, sh - sh0), 1.0)) * quality, 2.0);
# endif
}
return 1.0;
Expand Down