void GenerateWavesSpectrum()
{
// Slope variance due to all waves, by integrating over the full spectrum.
// Used by the BRDF rendering model
float theoreticSlopeVariance = 0.0f;
float k = 5e-3f;
while (k < 1e3f)
{
float nextK = k * 1.001f;
theoreticSlopeVariance += k * k * Spectrum(k, 0, true) * (nextK - k);
k = nextK;
}
float[] spectrum01 = new float[m_fourierGridSize * m_fourierGridSize * 4];
float[] spectrum23 = new float[m_fourierGridSize * m_fourierGridSize * 4];
int idx;
float i;
float j;
float totalSlopeVariance = 0.0f;
Vector2 sample12XY;
Vector2 sample12ZW;
Vector2 sample34XY;
Vector2 sample34ZW;
UnityEngine.Random.seed = 0;
for (int x = 0; x < m_fourierGridSize; x++)
{
for (int y = 0; y < m_fourierGridSize; y++)
{
idx = x + y * m_fourierGridSize;
i = (x >= m_fourierGridSize / 2) ? (float)(x - m_fourierGridSize) : (float)x;
j = (y >= m_fourierGridSize / 2) ? (float)(y - m_fourierGridSize) : (float)y;
sample12XY = GetSpectrumSample(i, j, m_gridSizes.x, Mathf.PI / m_gridSizes.x);
sample12ZW = GetSpectrumSample(i, j, m_gridSizes.y, Mathf.PI * m_fsize / m_gridSizes.x);
sample34XY = GetSpectrumSample(i, j, m_gridSizes.z, Mathf.PI * m_fsize / m_gridSizes.y);
sample34ZW = GetSpectrumSample(i, j, m_gridSizes.w, Mathf.PI * m_fsize / m_gridSizes.z);
spectrum01[idx * 4 + 0] = sample12XY.x;
spectrum01[idx * 4 + 1] = sample12XY.y;
spectrum01[idx * 4 + 2] = sample12ZW.x;
spectrum01[idx * 4 + 3] = sample12ZW.y;
spectrum23[idx * 4 + 0] = sample34XY.x;
spectrum23[idx * 4 + 1] = sample34XY.y;
spectrum23[idx * 4 + 2] = sample34ZW.x;
spectrum23[idx * 4 + 3] = sample34ZW.y;
i *= 2.0f * Mathf.PI;
j *= 2.0f * Mathf.PI;
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.x, j / m_gridSizes.x, sample12XY);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.y, j / m_gridSizes.y, sample12ZW);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.z, j / m_gridSizes.z, sample34XY);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.w, j / m_gridSizes.w, sample34ZW);
}
}
//Write floating point data into render texture
m_writeFloat.WriteIntoRenderTexture(m_spectrum01, 4, spectrum01);
m_writeFloat.WriteIntoRenderTexture(m_spectrum23, 4, spectrum23);
if (!SystemInfo.supportsComputeShaders)
{
// Compute variance for the BRDF
// copied from the dx9 project
float slopeVarianceDelta = 0.5f * (theoreticSlopeVariance - totalSlopeVariance);
//
m_varianceMax = new Vector2(float.NegativeInfinity, float.NegativeInfinity);
Vector2[, , ] variance32bit = new Vector2[m_varianceSize, m_varianceSize, m_varianceSize];
Color[] variance8bit = new Color[m_varianceSize * m_varianceSize * m_varianceSize];
//
for (int x = 0; x < m_varianceSize; x++)
{
for (int y = 0; y < m_varianceSize; y++)
{
for (int z = 0; z < m_varianceSize; z++)
{
variance32bit [x, y, z] = ComputeVariance(slopeVarianceDelta, spectrum01, spectrum23, x, y, z);
//problematic line
if (variance32bit [x, y, z].x > m_varianceMax.x)
{
m_varianceMax.x = variance32bit [x, y, z].x;
}
if (variance32bit [x, y, z].y > m_varianceMax.y)
{
m_varianceMax.y = variance32bit [x, y, z].y;
}
}
}
}
for (int x = 0; x < m_varianceSize; x++)
{
for (int y = 0; y < m_varianceSize; y++)
{
for (int z = 0; z < m_varianceSize; z++)
{
idx = x + y * m_varianceSize + z * m_varianceSize * m_varianceSize;
variance8bit [idx] = new Color(variance32bit [x, y, z].x / m_varianceMax.x, variance32bit [x, y, z].y / m_varianceMax.y, 0.0f, 1.0f);
}
}
}
m_varianceTexture.SetPixels(variance8bit);
m_varianceTexture.Apply();
m_maxSlopeVariance = 0.0f;
for (int v = 0; v < m_varianceSize * m_varianceSize * m_varianceSize; v++)
{
m_maxSlopeVariance = Mathf.Max(m_maxSlopeVariance, variance8bit [v].r * m_varianceMax.x);
m_maxSlopeVariance = Mathf.Max(m_maxSlopeVariance, variance8bit [v].g * m_varianceMax.y);
}
}
else
{
m_varianceShader = ShaderReplacer.Instance.LoadedComputeShaders["SlopeVariance"];
m_varianceShader.SetFloat("_SlopeVarianceDelta", 0.5f * (theoreticSlopeVariance - totalSlopeVariance));
m_varianceShader.SetFloat("_VarianceSize", (float)m_varianceSize);
m_varianceShader.SetFloat("_Size", m_fsize);
m_varianceShader.SetVector("_GridSizes", m_gridSizes);
m_varianceShader.SetTexture(0, "_Spectrum01", m_spectrum01);
m_varianceShader.SetTexture(0, "_Spectrum23", m_spectrum23);
m_varianceShader.SetTexture(0, "des", m_varianceRenderTexture);
m_varianceShader.Dispatch(0, m_varianceSize / 4, m_varianceSize / 4, m_varianceSize / 4);
//Find the maximum value for slope variance
ComputeBuffer buffer = new ComputeBuffer(m_varianceSize * m_varianceSize * m_varianceSize, sizeof(float));
CBUtility.ReadFromRenderTexture(m_varianceRenderTexture, 1, buffer, ShaderReplacer.Instance.LoadedComputeShaders["ReadData"]);
float[] varianceData = new float[m_varianceSize * m_varianceSize * m_varianceSize];
buffer.GetData(varianceData);
m_maxSlopeVariance = 0.0f;
for (int v = 0; v < m_varianceSize * m_varianceSize * m_varianceSize; v++)
{
m_maxSlopeVariance = Mathf.Max(m_maxSlopeVariance, varianceData[v]);
}
buffer.Release();
}
}
void GenerateWavesSpectrum()
{
// Slope variance due to all waves, by integrating over the full spectrum.
// Used by the BRDF rendering model
float theoreticSlopeVariance = 0.0f;
float k = 5e-3f;
while (k < 1e3f)
{
float nextK = k * 1.001f;
theoreticSlopeVariance += k * k * Spectrum(k, 0, true) * (nextK - k);
k = nextK;
}
float[] spectrum01 = new float[m_fourierGridSize * m_fourierGridSize * 4];
float[] spectrum23 = new float[m_fourierGridSize * m_fourierGridSize * 4];
int idx;
float i;
float j;
float totalSlopeVariance = 0.0f;
Vector2 sample12XY;
Vector2 sample12ZW;
Vector2 sample34XY;
Vector2 sample34ZW;
UnityEngine.Random.seed = 0;
for (int x = 0; x < m_fourierGridSize; x++)
{
for (int y = 0; y < m_fourierGridSize; y++)
{
idx = x + y * m_fourierGridSize;
i = (x >= m_fourierGridSize / 2) ? (float)(x - m_fourierGridSize) : (float)x;
j = (y >= m_fourierGridSize / 2) ? (float)(y - m_fourierGridSize) : (float)y;
sample12XY = GetSpectrumSample(i, j, m_gridSizes.x, Mathf.PI / m_gridSizes.x);
sample12ZW = GetSpectrumSample(i, j, m_gridSizes.y, Mathf.PI * m_fsize / m_gridSizes.x);
sample34XY = GetSpectrumSample(i, j, m_gridSizes.z, Mathf.PI * m_fsize / m_gridSizes.y);
sample34ZW = GetSpectrumSample(i, j, m_gridSizes.w, Mathf.PI * m_fsize / m_gridSizes.z);
spectrum01[idx * 4 + 0] = sample12XY.x;
spectrum01[idx * 4 + 1] = sample12XY.y;
spectrum01[idx * 4 + 2] = sample12ZW.x;
spectrum01[idx * 4 + 3] = sample12ZW.y;
spectrum23[idx * 4 + 0] = sample34XY.x;
spectrum23[idx * 4 + 1] = sample34XY.y;
spectrum23[idx * 4 + 2] = sample34ZW.x;
spectrum23[idx * 4 + 3] = sample34ZW.y;
i *= 2.0f * Mathf.PI;
j *= 2.0f * Mathf.PI;
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.x, j / m_gridSizes.x, sample12XY);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.y, j / m_gridSizes.y, sample12ZW);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.z, j / m_gridSizes.z, sample34XY);
totalSlopeVariance += GetSlopeVariance(i / m_gridSizes.w, j / m_gridSizes.w, sample34ZW);
}
}
//Write floating point data into render texture
m_writeFloat.WriteIntoRenderTexture(m_spectrum01, 4, spectrum01);
m_writeFloat.WriteIntoRenderTexture(m_spectrum23, 4, spectrum23);
// Compute variance for the BRDF
// copied from the dx9 project
float slopeVarianceDelta = 0.5f * (theoreticSlopeVariance - totalSlopeVariance);
//
m_varianceMax = new Vector2(float.NegativeInfinity, float.NegativeInfinity);
Vector2[, , ] variance32bit = new Vector2[m_varianceSize, m_varianceSize, m_varianceSize];
Color[] variance8bit = new Color[m_varianceSize * m_varianceSize * m_varianceSize];
//
for (int x = 0; x < m_varianceSize; x++)
{
for (int y = 0; y < m_varianceSize; y++)
{
for (int z = 0; z < m_varianceSize; z++)
{
variance32bit[x, y, z] = ComputeVariance(slopeVarianceDelta, spectrum01, spectrum23, x, y, z);
//problematic line
if (variance32bit[x, y, z].x > m_varianceMax.x)
{
m_varianceMax.x = variance32bit[x, y, z].x;
}
if (variance32bit[x, y, z].y > m_varianceMax.y)
{
m_varianceMax.y = variance32bit[x, y, z].y;
}
}
}
}
for (int x = 0; x < m_varianceSize; x++)
{
for (int y = 0; y < m_varianceSize; y++)
{
for (int z = 0; z < m_varianceSize; z++)
{
idx = x + y * m_varianceSize + z * m_varianceSize * m_varianceSize;
variance8bit[idx] = new Color(variance32bit[x, y, z].x / m_varianceMax.x, variance32bit[x, y, z].y / m_varianceMax.y, 0.0f, 1.0f);
}
}
}
m_variance.SetPixels(variance8bit);
m_variance.Apply();
m_maxSlopeVariance = 0.0f;
for (int v = 0; v < m_varianceSize * m_varianceSize * m_varianceSize; v++)
{
m_maxSlopeVariance = Mathf.Max(m_maxSlopeVariance, variance8bit[v].r * m_varianceMax.x);
m_maxSlopeVariance = Mathf.Max(m_maxSlopeVariance, variance8bit[v].g * m_varianceMax.y);
}
}
