57 lines
1.6 KiB
HLSL
57 lines
1.6 KiB
HLSL
//UNITY_SHADER_NO_UPGRADE
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#ifndef WIND_ANIM_INCLUDE
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#define WIND_ANIM_INCLUDE
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inline float4 SmoothCurve( float4 x ) {
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return x * x *( 3.0 - 2.0 * x );
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}
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inline float4 TriangleWave( float4 x ) {
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return abs( frac( x + 0.5 ) * 2.0 - 1.0 );
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}
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inline float4 SmoothTriangleWave( float4 x ) {
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return SmoothCurve( TriangleWave( x ) );
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}
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inline float4 ClothWindAnim(float4 pos, float3 normal, float4 animParams,float4 wind,float2 time)
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{
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// animParams.x = branch phase
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// animParams.y = edge flutter factor
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// animParams.z = primary factor
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// animParams.w = secondary factor
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float fDetailAmp = 0.1f;
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float fBranchAmp = 0.3f;
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// Phases (object, vertex, branch)
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float fObjPhase = dot(unity_ObjectToWorld[3].xyz, 1);
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float fBranchPhase = fObjPhase + animParams.x;
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float fVtxPhase = dot(pos.xyz, animParams.y + fBranchPhase);
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// x is used for edges; y is used for branches
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float2 vWavesIn = time + float2(fVtxPhase, fBranchPhase );
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// 1.975, 0.793, 0.375, 0.193 are good frequencies
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float4 vWaves = (frac( vWavesIn.xxyy * float4(1.975, 0.793, 0.375, 0.193) ) * 2.0 - 1.0);
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vWaves = SmoothTriangleWave( vWaves );
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float2 vWavesSum = vWaves.xz + vWaves.yw;
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// Edge (xz) and branch bending (y)
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float3 bend = animParams.y * fDetailAmp * normal.xyz;
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bend.y = animParams.w * fBranchAmp;
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pos.xyz += ((vWavesSum.xyx * bend)*wind.w + (wind.xyz * vWavesSum.y * animParams.w)) * wind.w;
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// Primary bending
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// Displace position
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pos.xyz += animParams.z * wind.xyz;
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return pos;
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}
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#endif //WIND_ANIM_INCLUDE
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