116 lines
3.6 KiB
HLSL
116 lines
3.6 KiB
HLSL
#ifndef UNIVERSAL_WAVING_GRASS_INPUT_INCLUDED
|
|
#define UNIVERSAL_WAVING_GRASS_INPUT_INCLUDED
|
|
|
|
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
|
|
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/SurfaceInput.hlsl"
|
|
|
|
CBUFFER_START(UnityPerMaterial)
|
|
float4 _MainTex_ST;
|
|
half4 _BaseColor;
|
|
half4 _SpecColor;
|
|
half4 _EmissionColor;
|
|
half _Cutoff;
|
|
half _Shininess;
|
|
CBUFFER_END
|
|
|
|
#define _Surface 0.0 // Grass is always opaque
|
|
|
|
// Terrain engine shader helpers
|
|
CBUFFER_START(TerrainGrass)
|
|
half4 _WavingTint;
|
|
float4 _WaveAndDistance; // wind speed, wave size, wind amount, max sqr distance
|
|
float4 _CameraPosition; // .xyz = camera position, .w = 1 / (max sqr distance)
|
|
float3 _CameraRight, _CameraUp;
|
|
CBUFFER_END
|
|
|
|
TEXTURE2D(_MainTex);
|
|
SAMPLER(sampler_MainTex);
|
|
float4 _MainTex_TexelSize;
|
|
float4 _MainTex_MipInfo;
|
|
|
|
// ---- Grass helpers
|
|
|
|
// Calculate a 4 fast sine-cosine pairs
|
|
// val: the 4 input values - each must be in the range (0 to 1)
|
|
// s: The sine of each of the 4 values
|
|
// c: The cosine of each of the 4 values
|
|
void FastSinCos (float4 val, out float4 s, out float4 c) {
|
|
val = val * 6.408849 - 3.1415927;
|
|
// powers for taylor series
|
|
float4 r5 = val * val; // wavevec ^ 2
|
|
float4 r6 = r5 * r5; // wavevec ^ 4;
|
|
float4 r7 = r6 * r5; // wavevec ^ 6;
|
|
float4 r8 = r6 * r5; // wavevec ^ 8;
|
|
|
|
float4 r1 = r5 * val; // wavevec ^ 3
|
|
float4 r2 = r1 * r5; // wavevec ^ 5;
|
|
float4 r3 = r2 * r5; // wavevec ^ 7;
|
|
|
|
|
|
//Vectors for taylor's series expansion of sin and cos
|
|
float4 sin7 = {1, -0.16161616, 0.0083333, -0.00019841};
|
|
float4 cos8 = {-0.5, 0.041666666, -0.0013888889, 0.000024801587};
|
|
|
|
// sin
|
|
s = val + r1 * sin7.y + r2 * sin7.z + r3 * sin7.w;
|
|
|
|
// cos
|
|
c = 1 + r5 * cos8.x + r6 * cos8.y + r7 * cos8.z + r8 * cos8.w;
|
|
}
|
|
|
|
half4 TerrainWaveGrass (inout float4 vertex, float waveAmount, half4 color)
|
|
{
|
|
half4 _waveXSize = half4(0.012, 0.02, 0.06, 0.024) * _WaveAndDistance.y;
|
|
half4 _waveZSize = half4 (0.006, .02, 0.02, 0.05) * _WaveAndDistance.y;
|
|
half4 waveSpeed = half4 (1.2, 2, 1.6, 4.8);
|
|
|
|
half4 _waveXmove = half4(0.024, 0.04, -0.12, 0.096);
|
|
half4 _waveZmove = half4 (0.006, .02, -0.02, 0.1);
|
|
|
|
float4 waves;
|
|
waves = vertex.x * _waveXSize;
|
|
waves += vertex.z * _waveZSize;
|
|
|
|
// Add in time to model them over time
|
|
waves += _WaveAndDistance.x * waveSpeed;
|
|
|
|
float4 s, c;
|
|
waves = frac (waves);
|
|
FastSinCos (waves, s,c);
|
|
|
|
s = s * s;
|
|
|
|
s = s * s;
|
|
|
|
half lighting = dot (s, normalize (half4 (1,1,.4,.2))) * 0.7;
|
|
|
|
s = s * waveAmount;
|
|
|
|
half3 waveMove = 0;
|
|
waveMove.x = dot (s, _waveXmove);
|
|
waveMove.z = dot (s, _waveZmove);
|
|
|
|
vertex.xz -= waveMove.xz * _WaveAndDistance.z;
|
|
|
|
// apply color animation
|
|
half3 waveColor = lerp (real3(0.5, 0.5, 0.5), _WavingTint.rgb, lighting);
|
|
|
|
// Fade the grass out before detail distance.
|
|
// Saturate because Radeon HD drivers on OS X 10.4.10 don't saturate vertex colors properly.
|
|
half3 offset = vertex.xyz - _CameraPosition.xyz;
|
|
color.a = saturate (2 * (_WaveAndDistance.w - dot (offset, offset)) * _CameraPosition.w);
|
|
|
|
return half4(2 * waveColor * color.rgb, color.a);
|
|
}
|
|
|
|
void TerrainBillboardGrass( inout float4 pos, float2 offset )
|
|
{
|
|
float3 grasspos = pos.xyz - _CameraPosition.xyz;
|
|
if (dot(grasspos, grasspos) > _WaveAndDistance.w)
|
|
offset = 0.0;
|
|
pos.xyz += offset.x * _CameraRight.xyz;
|
|
pos.y += offset.y;
|
|
}
|
|
|
|
#endif
|