#if defined(_TERRAIN_8_SPLATS)
#ifdef _TERRAIN_8_LAYERS
#elif defined(_TERRAIN_7_SPLATS)
#define _LAYER_COUNT 7
#elif defined(_TERRAIN_6_SPLATS)
#define _LAYER_COUNT 6
#elif defined(_TERRAIN_5_SPLATS)
#define _LAYER_COUNT 5
#elif defined(_TERRAIN_4_SPLATS)
#define _LAYER_COUNT 4
#elif defined(_TERRAIN_3_SPLATS)
#define _LAYER_COUNT 3
#elif defined(_TERRAIN_2_SPLATS)
#define _LAYER_COUNT 2
#define _LAYER_COUNT 1
#define _LAYER_COUNT 4
TEXTURE2D(_Height##n); \
TEXTURE2D(_Mask##n); \
float _Density##n; \
float _HeightCenter##n; \
float _HeightAmplitude##n
DECLARE_TERRAIN_LAYER(3);
DECLARE_TERRAIN_LAYER(4);
DECLARE_TERRAIN_LAYER(5);
DECLARE_TERRAIN_LAYER(6);
DECLARE_TERRAIN_LAYER(7);
#undef DECLARE_TERRAIN_LAYER
TEXTURE2D(_Control1);
float GetMaxHeight(float4 heights0
#if _LAYER_COUNT > 4
, float4 heights1
#ifdef _TERRAIN_8_LAYERS
DECLARE_TERRAIN_LAYER(4);
DECLARE_TERRAIN_LAYER(5);
DECLARE_TERRAIN_LAYER(6);
DECLARE_TERRAIN_LAYER(7);
TEXTURE2D(_Control1);
)
#undef DECLARE_TERRAIN_LAYER
float _HeightTransition;
float GetSumHeight(float4 heights0, float4 heights1)
float maxHeight = heights0.r;
#if _LAYER_COUNT > 1
maxHeight = max(maxHeight, heights0.g);
#endif
#if _LAYER_COUNT > 2
maxHeight = max(maxHeight, heights0.b);
#endif
#if _LAYER_COUNT > 3
maxHeight = max(maxHeight, heights0.a);
#endif
#if _LAYER_COUNT > 4
maxHeight = max(maxHeight, heights1.r);
#endif
#if _LAYER_COUNT > 5
maxHeight = max(maxHeight, heights1.g);
#endif
#if _LAYER_COUNT > 6
maxHeight = max(maxHeight, heights1.b);
#endif
#if _LAYER_COUNT > 7
maxHeight = max(maxHeight, heights1.a);
#endif
return maxHeight;
float sumHeight = heights0.x;
sumHeight += heights0.y;
sumHeight += heights0.z;
sumHeight += heights0.w;
#ifdef _TERRAIN_8_LAYERS
sumHeight += heights1.x;
sumHeight += heights1.y;
sumHeight += heights1.z;
sumHeight += heights1.w;
#endif
return sumHeight;
float GetSumHeight(float4 heights0
#if _LAYER_COUNT > 4
, float4 heights1
#endif
)
float3 SampleNormalGrad(TEXTURE2D_ARGS(textureName, samplerName), float2 uv, float2 dxuv, float2 dyuv, float3 tangentWS, float3 bitangentWS)
float sumHeight = heights0.r;
#if _LAYER_COUNT > 1
sumHeight += heights0.g;
#endif
#if _LAYER_COUNT > 2
sumHeight += heights0.b;
#endif
#if _LAYER_COUNT > 3
sumHeight += heights0.a;
#endif
#if _LAYER_COUNT > 4
sumHeight += heights1.r;
float4 nrm = SAMPLE_TEXTURE2D_GRAD(textureName, samplerName, uv, dxuv, dyuv);
#ifdef SURFACE_GRADIENT
#ifdef UNITY_NO_DXT5nm
real2 deriv = UnpackDerivativeNormalRGB(nrm, 1);
#else
real2 deriv = UnpackDerivativeNormalRGorAG(nrm, 1);
#endif
return SurfaceGradientFromTBN(deriv, tangentWS, bitangentWS);
#else
#ifdef UNITY_NO_DXT5nm
return UnpackNormalRGB(nrm, 1);
#else
return UnpackNormalmapRGorAG(nrm, 1);
#endif
#if _LAYER_COUNT > 5
sumHeight += heights1.g;
#endif
#if _LAYER_COUNT > 6
sumHeight += heights1.b;
#endif
#if _LAYER_COUNT > 7
sumHeight += heights1.a;
#endif
return sumHeight;
}
float4 RemapMasks(float4 masks, float blendMask, float heightCenter, float heightAmplitude, float smoothness, float metallic)
{
return float4(
(masks.r * blendMask - heightCenter) * heightAmplitude,
masks.g * smoothness,
masks.b * metallic,
0);
float _HeightTransition;
#ifdef OVERRIDE_SAMPLER_NAME
#define sampler_Splat0 OVERRIDE_SAMPLER_NAME
#endif
// Returns layering blend mask after application of height based blend.
void ApplyHeightBlend(float4 weightedHeights0, float4 weightedHeights1, inout float4 blendMasks0, inout float4 blendMasks1)
void TerrainSplatBlend(float2 uv, float3 tangentWS, float3 bitangentWS,
out float3 outAlbedo, out float3 outNormalTS, out float outSmoothness, out float outMetallic)
float maxHeight = GetMaxHeight(weightedHeights0
#if _LAYER_COUNT > 4
, weightedHeights1
#endif
);
// Make sure that transition is not zero otherwise the next computation will be wrong.
// The epsilon here also has to be bigger than the epsilon in the next computation.
float transition = max(_HeightTransition, 1e-5);
// TODO: triplanar and SURFACE_GRADIENT?
// TODO: POM
// The goal here is to have all but the highest layer at negative heights, then we add the transition so that if the next highest layer is near transition it will have a positive value.
// Then we clamp this to zero and normalize everything so that highest layer has a value of 1.
weightedHeights0 = weightedHeights0 - maxHeight.xxxx;
// We need to add an epsilon here for active layers (hence the blendMask again) so that at least a layer shows up if everything's too low.
weightedHeights0 = (max(0, weightedHeights0 + transition) + 1e-6) * blendMasks0;
float4 albedo[_LAYER_COUNT];
float3 normal[_LAYER_COUNT];
float4 masks[_LAYER_COUNT];
#if _LAYER_COUNT > 4
weightedHeights1 = weightedHeights1 - maxHeight.xxxx;
weightedHeights1 = (max(0, weightedHeights1 + transition) + 1e-6) * blendMasks1;
#ifdef _NORMALMAP
#define SampleNormal(i) SampleNormalGrad(_Normal##i, sampler_Splat0, splatuv, splatdxuv, splatdyuv, tangentWS, bitangentWS)
#else
#define SampleNormal(i) float3(0, 0, 1)
// Normalize
float totalHeight = GetSumHeight(weightedHeights0
#if _LAYER_COUNT > 4
, weightedHeights1
#ifdef _MASKMAP
#define SampleMasks(i, blendMask) RemapMasks(SAMPLE_TEXTURE2D_GRAD(_Mask##i, sampler_Splat0, splatuv, splatdxuv, splatdyuv), blendMask, _HeightCenter##i, _HeightAmplitude##i, _Smoothness##i, _Metallic##i)
#else
#define SampleMasks(i, blendMask) float4(0, albedo[i].a * _Smoothness##i, _Metallic##i, 0)
);
blendMasks0 = weightedHeights0 / totalHeight.xxxx;
#if _LAYER_COUNT > 4
blendMasks1 = weightedHeights1 / totalHeight.xxxx;
#endif
#define SampleResults(i, mask) \
UNITY_BRANCH if (mask > 0) \
{ \
float2 splatuv = uv * _Splat##i##_ST.xy + _Splat##i##_ST.zw; \
float2 splatdxuv = dxuv * _Splat##i##_ST.x; \
float2 splatdyuv = dyuv * _Splat##i##_ST.y; \
albedo[i] = SAMPLE_TEXTURE2D_GRAD(_Splat##i, sampler_Splat0, splatuv, splatdxuv, splatdyuv); \
normal[i] = SampleNormal(i); \
masks[i] = SampleMasks(i, mask); \
} \
else \
{ \
albedo[i] = float4(0, 0, 0, 0); \
normal[i] = float3(0, 0, 0); \
masks[i] = float4(-1, 0, 0, 0); \
}
float2 dxuv = ddx(uv);
float2 dyuv = ddy(uv);
float4 blendMasks0 = SAMPLE_TEXTURE2D(_Control0, sampler_Control0, uv);
#ifdef _TERRAIN_8_LAYERS
float4 blendMasks1 = SAMPLE_TEXTURE2D(_Control1, sampler_Control0, uv);
#else
float4 blendMasks1 = float4(0, 0, 0, 0);
#endif
SampleResults(0, blendMasks0.x);
SampleResults(1, blendMasks0.y);
SampleResults(2, blendMasks0.z);
SampleResults(3, blendMasks0.w);
#ifdef _TERRAIN_8_LAYERS
SampleResults(4, blendMasks1.x);
SampleResults(5, blendMasks1.y);
SampleResults(6, blendMasks1.z);
SampleResults(7, blendMasks1.w);
#endif
#undef SampleNormal
#undef SampleMasks
#undef SampleResults
float weights[_LAYER_COUNT];
ZERO_INITIALIZE_ARRAY(float, weights, _LAYER_COUNT);
#if defined(_TERRAIN_BLEND_HEIGHT) && defined(_MASKMAP)
// Modify blendMask to take into account the height of the layer. Higher height should be more visible.
float maxHeight = masks[0].x;
maxHeight = max(maxHeight, masks[1].x);
maxHeight = max(maxHeight, masks[2].x);
maxHeight = max(maxHeight, masks[3].x);
#ifdef _TERRAIN_8_LAYERS
maxHeight = max(maxHeight, masks[4].x);
maxHeight = max(maxHeight, masks[5].x);
maxHeight = max(maxHeight, masks[6].x);
maxHeight = max(maxHeight, masks[7].x);
#endif
// Make sure that transition is not zero otherwise the next computation will be wrong.
// The epsilon here also has to be bigger than the epsilon in the next computation.
float transition = max(_HeightTransition, 1e-5);
// The goal here is to have all but the highest layer at negative heights, then we add the transition so that if the next highest layer is near transition it will have a positive value.
// Then we clamp this to zero and normalize everything so that highest layer has a value of 1.
float4 weightedHeights0 = { masks[0].x, masks[1].x, masks[2].x, masks[3].x };
weightedHeights0 = weightedHeights0 - maxHeight.xxxx;
// We need to add an epsilon here for active layers (hence the blendMask again) so that at least a layer shows up if everything's too low.
weightedHeights0 = (max(0, weightedHeights0 + transition) + 1e-6) * blendMasks0;
#ifdef _TERRAIN_8_LAYERS
float4 weightedHeights1 = { masks[4].x, masks[5].x, masks[6].x, masks[7].x };
weightedHeights1 = weightedHeights1 - maxHeight.xxxx;
weightedHeights1 = (max(0, weightedHeights1 + transition) + 1e-6) * blendMasks1;
#else
float4 weightedHeights1 = { 0, 0, 0, 0 };
#endif
// Normalize
float sumHeight = GetSumHeight(weightedHeights0, weightedHeights1);
blendMasks0 = weightedHeights0 / sumHeight.xxxx;
#ifdef _TERRAIN_8_LAYERS
blendMasks1 = weightedHeights1 / sumHeight.xxxx;
#endif
#elif defined(_TERRAIN_BLEND_DENSITY) && defined(_MASKMAP)
// Denser layers are more visible.
float4 opacityAsDensity0 = saturate((float4(albedo[0].a, albedo[1].a, albedo[2].a, albedo[3].a) - (float4(1.0, 1.0, 1.0, 1.0) - blendMasks0)) * 20.0); // 20.0 is the number of steps in inputAlphaMask (Density mask. We decided 20 empirically)
float4 useOpacityAsDensityParam0 = { _Density0, _Density1, _Density2, _Density3 };
blendMasks0 = lerp(blendMasks0, opacityAsDensity0, useOpacityAsDensityParam0);
#ifdef _TERRAIN_8_LAYERS
float4 opacityAsDensity1 = saturate((float4(albedo[4].a, albedo[5].a, albedo[6].a, albedo[7].a) - (float4(1.0, 1.0, 1.0, 1.0) - blendMasks1)) * 20.0); // 20.0 is the number of steps in inputAlphaMask (Density mask. We decided 20 empirically)
float4 useOpacityAsDensityParam1 = { _Density4, _Density5, _Density6, _Density7 };
blendMasks1 = lerp(blendMasks1, opacityAsDensity1, useOpacityAsDensityParam1);
#endif
#endif
weights[0] = blendMasks0.x;
weights[1] = blendMasks0.y;
weights[2] = blendMasks0.z;
weights[3] = blendMasks0.w;
#ifdef _TERRAIN_8_LAYERS
weights[4] = blendMasks1.x;
weights[5] = blendMasks1.y;
weights[6] = blendMasks1.z;
weights[7] = blendMasks1.w;
#endif
#if defined(_TERRAIN_BLEND_DENSITY) && defined(_MASKMAP)
// calculate weight of each layers
// Algorithm is like this:
// Top layer have priority on others layers
// If a top layer doesn't use the full weight, the remaining can be use by the following layer.
float weightsSum = 0.0;
UNITY_UNROLL
for (int i = _LAYER_COUNT - 1; i >= 0; --i)
{
weights[i] = min(weights[i], (1.0 - weightsSum));
weightsSum = saturate(weightsSum + weights[i]);
}
#endif
outAlbedo = 0;
outNormalTS = 0;
float2 outMasks = 0;
UNITY_UNROLL for (int i = 0; i < _LAYER_COUNT; ++i)
{
outAlbedo += albedo[i].rgb * weights[i];
outNormalTS += normal[i].rgb * weights[i];
outMasks += masks[i].yz * weights[i];
}
#ifndef _NORMALMAP
#ifdef SURFACE_GRADIENT
outNormalTS = float3(0.0, 0.0, 0.0); // No gradient
#else
outNormalTS = float3(0.0, 0.0, 1.0);
#endif
#endif
outSmoothness = outMasks.x;
outMetallic = outMasks.y;
}
Yao Xiaoling
7 年前