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我試圖在NVidia FX編寫器中編寫「perlin」噪聲着色器。但是,無論我如何調整噪音功能,它都會返回100%白色或100%黑色。我不知道如何解決這個問題,甚至是問題出在哪裏。我的「perlin」噪聲效果着色器產生全白或全黑
編輯:如果你已經看到This page,你可能知道我在哪裏得到的代碼。想象一下,我會從一個我已經在CPU上工作的方法開始。
請幫忙。
float Noise1(int x, int y)
{
int n = x + y * 57;
// int n = x + y * 1376312627;
// n = n * n;
// n = (int)pow(n * pow(2, 13), n);
// return (1.0 - ((n * (n * n * 15731 + 789221) + 1376312589) + 0x7fffffff)/1073741824.0);
// return abs(((n * (n * n * 15731 + 789221) + 1376312589) + 0x7fffffff)/2147483647.0);
// return (1.0 - ((n * (n * n * 15731 + 789221) + 1376312589) + 0x7fffffff)/2147483647.0);
// return (n/2147483647.0);
return (((float)n)/500.0);
// return n = 2147483647.0;
}
float SmoothNoise_1(int x, int y)
{
float corners = (Noise1(x-1, y-1) + Noise1(x+1, y-1) + Noise1(x-1, y+1) + Noise1(x+1, y+1))/16.0;
float sides = (Noise1(x-1, y) + Noise1(x+1, y) + Noise1(x, y-1) + Noise1(x, y+1))/8.0;
float center = Noise1(x, y)/4.0;
return corners + sides + center;
}
float Cosine_Interpolate(float a, float b, float x)
{
float ft = x * 3.1415927;
float f = (1 - cos(ft)) * 0.5;
return a*(1-f) + b*f;
}
float InterpolatedNoise_1(float x, float y)
{
int integer_X = (int)x;
float fractional_X = x - integer_X;
int integer_Y = (int)y;
float fractional_Y = y - integer_Y;
float v1 = SmoothNoise_1(integer_X, integer_Y);
float v2 = SmoothNoise_1(integer_X + 1, integer_Y);
float v3 = SmoothNoise_1(integer_X, integer_Y + 1);
float v4 = SmoothNoise_1(integer_X + 1, integer_Y + 1);
float i1 = Cosine_Interpolate(v1 , v2 , fractional_X);
float i2 = Cosine_Interpolate(v3 , v4 , fractional_X);
return Cosine_Interpolate(i1 , i2 , fractional_Y);
}
int width = 512;
int height = 512;
float4 PerlinNoise_2D(float2 xy : TEXCOORD0) : COLOR0
{
float4 total = 0;
// int p = persistence;
float p = 1.0;
// int n = Number_Of_Octaves - 1;
int n = 2;
for(int i = 0; i < n; ++i)
{
float frequency = pow(2, i);
float amplitude = pow(p, i);
/* total.a = InterpolatedNoise_1(xy.x * width * frequency, xy.y * height * frequency) * amplitude;
total.r = InterpolatedNoise_1(xy.x * width * frequency, xy.y * height * frequency) * amplitude;
total.g = InterpolatedNoise_1(xy.x * width * frequency, xy.y * height * frequency) * amplitude;
total.b = InterpolatedNoise_1(xy.x * width * frequency, xy.y * height * frequency) * amplitude; */
/* total.a = InterpolatedNoise_1(xy.x * frequency, xy.y * frequency) * amplitude;
total.r = InterpolatedNoise_1(xy.x * frequency, xy.y * frequency) * amplitude;
total.g = InterpolatedNoise_1(xy.x * frequency, xy.y * frequency) * amplitude;
total.b = InterpolatedNoise_1(xy.x * frequency, xy.y * frequency) * amplitude; */
total.a = InterpolatedNoise_1(xy.x * width, xy.y * height);
total.r = InterpolatedNoise_1(xy.x * width, xy.y * height);
total.g = InterpolatedNoise_1(xy.x * width, xy.y * height);
total.b = InterpolatedNoise_1(xy.x * width, xy.y * height);
}
return clamp(total, 0.0, 1.0);
// return (float)(int)(2147483647 + 2147483647 + 2147483647/2)/2147483647.0;
}
technique Perlin
{
pass p0
{
VertexShader = null;
PixelShader = compile ps_3_0 PerlinNoise_2D();
}
}
謝謝。
你的源代碼是http://freespace.virgin.net/hugo.elias/models/m_perlin.htm?只是想知道,我認識到這些功能的命名。旁註說,該網站沒有提到整個八度的事情不是'Perlin'噪音的一部分,而是http://en.wikipedia.org/wiki/Fractional_Brownian_motion。 – Dykam 2011-03-13 21:36:58
您必須在編輯之前發佈。 :)是的,那是我第一次遇到「perlin」噪音的地方。 – 2011-03-13 21:59:16