Files
2024-11-20 15:21:28 +01:00

891 lines
39 KiB
C#

using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
[CustomEditor(typeof(ProceduralTexture2D)), CanEditMultipleObjects]
public class ProceduralTexture2DEditor : Editor
{
ProceduralTexture2D[] targetAssets;
public void OnEnable()
{
Object[] monoObjects = targets;
targetAssets = new ProceduralTexture2D[monoObjects.Length];
for (int i = 0; i < monoObjects.Length; i++)
{
targetAssets[i] = monoObjects[i] as ProceduralTexture2D;
}
}
public override void OnInspectorGUI()
{
serializedObject.Update();
// Input Texture
EditorGUI.BeginChangeCheck();
EditorGUILayout.PropertyField(serializedObject.FindProperty("input"), new GUIContent("Texture"));
if (EditorGUI.EndChangeCheck())
{
serializedObject.ApplyModifiedProperties();
CopyInputTextureImportType(targetAssets[0]);
}
GUILayout.Space(10);
// Texture Type
EditorGUILayout.PropertyField(serializedObject.FindProperty("type"), new GUIContent("Texture Type"));
// Include alpha for color textures
if ((ProceduralTexture2D.TextureType)serializedObject.FindProperty("type").enumValueIndex == ProceduralTexture2D.TextureType.Color)
EditorGUILayout.PropertyField(serializedObject.FindProperty("includeAlpha"), new GUIContent("Include Alpha"));
GUILayout.Space(10);
// Filtering
EditorGUILayout.PropertyField(serializedObject.FindProperty("generateMipMaps"), new GUIContent("Generate Mip Maps"));
EditorGUILayout.PropertyField(serializedObject.FindProperty("filterMode"), new GUIContent("Filter mode"));
Rect sliderRect = GUILayoutUtility.GetLastRect();
if (serializedObject.FindProperty("generateMipMaps").boolValue == true)
{
sliderRect = new Rect(sliderRect.x, sliderRect.y + sliderRect.height, sliderRect.width, sliderRect.height);
PropertyIntSlider(sliderRect, serializedObject.FindProperty("anisoLevel"), 0, 16, new GUIContent("Aniso Level"));
GUILayoutUtility.GetRect(new GUIContent("Aniso Level"), EditorStyles.label);
}
GUILayout.Space(10);
// Compression
EditorGUILayout.PropertyField(serializedObject.FindProperty("compressionQuality"), new GUIContent("Compression"));
// Memory size display
string size = targetAssets.Length == 1 && targetAssets[0].memoryUsageBytes > 0 ?
SizeSuffix(targetAssets[0].memoryUsageBytes) : "--";
EditorGUILayout.LabelField("Size in memory: " + size, EditorStyles.centeredGreyMiniLabel);
GUILayout.Space(10);
// Apply changes button
GUILayout.BeginHorizontal();
GUILayout.FlexibleSpace();
if (GUILayout.Button("Apply"))
for (int i = 0; i < targetAssets.Length; i++)
PreprocessData(targetAssets[i]);
GUILayout.EndHorizontal();
// Normal compression warning
if (targetAssets[0].type == ProceduralTexture2D.TextureType.Normal && targetAssets[0].compressionQuality != ProceduralTexture2D.CompressionLevel.HighQuality)
EditorGUILayout.HelpBox("High quality compression recommended for normal maps", MessageType.Info);
// Unapplied changes warning
if (UnappliedSettingChanges(targetAssets[0]) == true)
EditorGUILayout.HelpBox("Unapplied settings", MessageType.Info);
serializedObject.ApplyModifiedProperties();
}
// A slider function that takes a SerializedProperty
void PropertyIntSlider(Rect position, SerializedProperty property, int leftValue, int rightValue, GUIContent label)
{
label = EditorGUI.BeginProperty(position, label, property);
EditorGUI.BeginChangeCheck();
var newValue = EditorGUI.IntSlider(position, label, property.intValue, leftValue, rightValue);
if (EditorGUI.EndChangeCheck())
property.intValue = newValue;
EditorGUI.EndProperty();
}
private readonly string[] SizeSuffixes =
{ "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
private string SizeSuffix(long value, int decimalPlaces = 1)
{
if (value < 0) { return "-" + SizeSuffix(-value); }
if (value == 0) { return string.Format("{0:n" + decimalPlaces + "} bytes", 0); }
// mag is 0 for bytes, 1 for KB, 2, for MB, etc.
int mag = (int)Mathf.Log(value, 1024);
// 1L << (mag * 10) == 2 ^ (10 * mag)
// [i.e. the number of bytes in the unit corresponding to mag]
decimal adjustedSize = (decimal)value / (1L << (mag * 10));
// make adjustment when the value is large enough that
// it would round up to 1000 or more
if (System.Math.Round(adjustedSize, decimalPlaces) >= 1000)
{
mag += 1;
adjustedSize /= 1024;
}
return string.Format("{0:n" + decimalPlaces + "} {1}",
adjustedSize,
SizeSuffixes[mag]);
}
private void CopyInputTextureImportType(ProceduralTexture2D target)
{
string path = AssetDatabase.GetAssetPath(target.input);
TextureImporter inputImporter = (TextureImporter)TextureImporter.GetAtPath(path);
switch (inputImporter.textureType)
{
case TextureImporterType.NormalMap:
target.type = ProceduralTexture2D.TextureType.Normal;
break;
default:
target.type = ProceduralTexture2D.TextureType.Color;
break;
}
}
private bool UnappliedSettingChanges(ProceduralTexture2D target)
{
if(target.currentInput != target.input
|| target.currentIncludeAlpha != target.includeAlpha
|| target.currentGenerateMipMaps != target.generateMipMaps
|| target.currentFilterMode != target.filterMode
|| target.currentAnisoLevel != target.anisoLevel
|| target.currentCompressionQuality != target.compressionQuality)
{
return true;
}
else
{
return false;
}
}
/*********************************************************************/
/*********************************************************************/
/*************Procedural Stochastic Texturing Pre-process*************/
/*********************************************************************/
/*********************************************************************/
const float GAUSSIAN_AVERAGE = 0.5f; // Expectation of the Gaussian distribution
const float GAUSSIAN_STD = 0.1666f; // Std of the Gaussian distribution
const int LUT_WIDTH = 128; // Size of the look-up table
private static int stepCounter = 0;
private static int totalSteps = 0;
struct TextureData
{
public Color[] data;
public int width;
public int height;
public TextureData(int w, int h)
{
width = w;
height = h;
data = new Color[w * h];
}
public TextureData(TextureData td)
{
width = td.width;
height = td.height;
data = new Color[width * height];
for (int y = 0; y < height; y++)
for (int x = 0; x < width; x++)
data[y * width + x] = td.data[y * width + x];
}
public Color GetColor(int w, int h)
{
return data[h * width + w];
}
public ref Color GetColorRef(int w, int h)
{
return ref data[h * width + w];
}
public void SetColorAt(int w, int h, Color value)
{
data[h * width + w] = value;
}
};
private static void PreprocessData(ProceduralTexture2D target)
{
if (target.input == null)
return;
// Init progress bar
stepCounter = 0;
totalSteps = (target.type != ProceduralTexture2D.TextureType.Other ? 4 : 0) + (target.type != ProceduralTexture2D.TextureType.Other ? 9 : 12) + 1;
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", target.name, (float)stepCounter / (totalSteps - 1));
// Section 1.4 Improvement: using a decorrelated color space for Color RGB and Normal XYZ textures
TextureFormat inputFormat = TextureFormat.RGB24;
TextureData albedoData = TextureToTextureData(target.input, ref inputFormat);
TextureData decorrelated = new TextureData(albedoData);
if (target.type != ProceduralTexture2D.TextureType.Other)
DecorrelateColorSpace(ref albedoData, ref decorrelated, ref target.colorSpaceVector1, ref target.colorSpaceVector2, ref target.colorSpaceVector3, ref target.colorSpaceOrigin, target.name);
ComputeCompressionScalers(target);
// Perform precomputations
TextureData Tinput = new TextureData(decorrelated.width, decorrelated.height);
TextureData invT = new TextureData(LUT_WIDTH, (int)(Mathf.Log((float)Tinput.width) / Mathf.Log(2.0f))); // Height = Number of prefiltered LUT levels
List<int> channelsToProcess = new List<int> { 0, 1, 2 };
if ((target.type == ProceduralTexture2D.TextureType.Color && target.includeAlpha == true) || target.type == ProceduralTexture2D.TextureType.Other)
channelsToProcess.Add(3);
Precomputations(ref decorrelated, channelsToProcess, ref Tinput, ref invT, target.name);
RescaleForCompression(target, ref Tinput);
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", target.name, (float)stepCounter++ / (totalSteps - 1));
// Serialize precomputed data and setup material
FinalizePrecomputedTextures(ref inputFormat, target, ref Tinput, ref invT);
target.memoryUsageBytes = target.Tinput.GetRawTextureData().Length + target.invT.GetRawTextureData().Length;
EditorUtility.ClearProgressBar();
// Update current applied settings
target.currentInput = target.input;
target.currentIncludeAlpha = target.includeAlpha;
target.currentGenerateMipMaps = target.generateMipMaps;
target.currentFilterMode = target.filterMode;
target.currentAnisoLevel = target.anisoLevel;
target.currentCompressionQuality = target.compressionQuality;
}
static TextureData TextureToTextureData(Texture2D input, ref TextureFormat inputFormat)
{
// Modify input texture import settings temporarily
string texpath = AssetDatabase.GetAssetPath(input);
TextureImporter importer = (TextureImporter)TextureImporter.GetAtPath(texpath);
TextureImporterCompression prev = importer.textureCompression;
TextureImporterType prevType = importer.textureType;
bool linearInput = importer.sRGBTexture == false || importer.textureType == TextureImporterType.NormalMap;
bool prevReadable = importer.isReadable;
if (importer != null)
{
importer.textureType = TextureImporterType.Default;
importer.isReadable = true;
importer.textureCompression = TextureImporterCompression.Uncompressed;
AssetDatabase.ImportAsset(texpath, ImportAssetOptions.ForceUpdate);
inputFormat = input.format;
}
// Copy input texture pixel data
Color[] colors = input.GetPixels();
TextureData res = new TextureData(input.width, input.height);
for (int x = 0; x < res.width; x++)
{
for (int y = 0; y < res.height; y++)
{
res.SetColorAt(x, y, linearInput || PlayerSettings.colorSpace == ColorSpace.Gamma ?
colors[y * res.width + x] : colors[y * res.width + x].linear);
}
}
// Revert input texture settings
if (importer != null)
{
importer.textureType = prevType;
importer.isReadable = prevReadable;
importer.textureCompression = prev;
AssetDatabase.ImportAsset(texpath, ImportAssetOptions.ForceUpdate);
}
return res;
}
static void FinalizePrecomputedTextures(ref TextureFormat inputFormat, ProceduralTexture2D target, ref TextureData Tinput, ref TextureData invT)
{
// Serialize precomputed data as new subasset texture. Reuse existing texture if possible to avoid breaking texture references in shadergraph.
if(target.Tinput == null)
{
target.Tinput = new Texture2D(Tinput.width, Tinput.height, inputFormat, target.generateMipMaps, true);
AssetDatabase.AddObjectToAsset(target.Tinput, target);
}
target.Tinput.Reinitialize(Tinput.width, Tinput.height, inputFormat, target.generateMipMaps);
target.Tinput.name = target.input.name + "_T";
target.Tinput.SetPixels(Tinput.data);
target.Tinput.wrapMode = TextureWrapMode.Repeat;
target.Tinput.filterMode = target.filterMode;
target.Tinput.anisoLevel = target.anisoLevel;
target.Tinput.Apply();
if (target.compressionQuality != ProceduralTexture2D.CompressionLevel.None)
{
if(target.compressionQuality == ProceduralTexture2D.CompressionLevel.HighQuality)
EditorUtility.CompressTexture(target.Tinput, TextureFormat.BC7, (int)target.compressionQuality);
else if (inputFormat == TextureFormat.RGBA32)
EditorUtility.CompressTexture(target.Tinput, TextureFormat.DXT5, (int)target.compressionQuality);
else
EditorUtility.CompressTexture(target.Tinput, TextureFormat.DXT1, (int)target.compressionQuality);
}
target.Tinput.Apply();
if (target.invT == null)
{
target.invT = new Texture2D(invT.width, invT.height, inputFormat, false, true);
AssetDatabase.AddObjectToAsset(target.invT, target);
}
target.invT.Reinitialize(invT.width, invT.height, inputFormat, false);
target.invT.name = target.input.name + "_invT";
target.invT.wrapMode = TextureWrapMode.Clamp;
target.invT.filterMode = FilterMode.Bilinear;
target.invT.SetPixels(invT.data);
target.invT.Apply();
// Update asset database
AssetDatabase.SaveAssets();
AssetDatabase.Refresh();
}
private static void Precomputations(
ref TextureData input, // input: example image
List<int> channels, // input: channels to process
ref TextureData Tinput, // output: T(input) image
ref TextureData invT, // output: T^{-1} look-up table
string assetName)
{
// Section 1.3.2 Applying the histogram transformation T on the input
foreach (int channel in channels)
{
ComputeTinput(ref input, ref Tinput, channel);
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
}
// Section 1.3.3 Precomputing the inverse histogram transformation T^{-1}
foreach (int channel in channels)
{
ComputeinvT(ref input, ref invT, channel);
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
}
// Section 1.5 Improvement: prefiltering the look-up table
foreach (int channel in channels)
{
PrefilterLUT(ref Tinput, ref invT, channel);
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
}
}
private static void ComputeCompressionScalers(ProceduralTexture2D target)
{
target.compressionScalers = Vector4.one;
if (target.compressionQuality != ProceduralTexture2D.CompressionLevel.None && target.type != ProceduralTexture2D.TextureType.Other)
{
target.compressionScalers.x = 1.0f / target.colorSpaceVector1.magnitude;
target.compressionScalers.y = 1.0f / target.colorSpaceVector2.magnitude;
target.compressionScalers.z = 1.0f / target.colorSpaceVector3.magnitude;
}
}
private static void RescaleForCompression(ProceduralTexture2D target, ref TextureData Tinput)
{
int channelCount = (target.type == ProceduralTexture2D.TextureType.Color && target.includeAlpha == true) || target.type == ProceduralTexture2D.TextureType.Other ?
4 : 3;
// If we use DXT compression
// we need to rescale the Gaussian channels (see Section 1.6)
if (target.compressionQuality != ProceduralTexture2D.CompressionLevel.None && target.type != ProceduralTexture2D.TextureType.Other)
{
for (int y = 0; y < Tinput.height; y++)
for (int x = 0; x < Tinput.width; x++)
for (int i = 0; i < channelCount; i++)
{
float v = Tinput.GetColor(x, y)[i];
v = (v - 0.5f) / target.compressionScalers[i] + 0.5f;
Tinput.GetColorRef(x, y)[i] = v;
}
}
}
/*****************************************************************************/
/**************** Section 1.3.1 Target Gaussian distribution *****************/
/*****************************************************************************/
private static float Erf(float x)
{
// Save the sign of x
int sign = 1;
if (x < 0)
sign = -1;
x = Mathf.Abs(x);
// A&S formula 7.1.26
float t = 1.0f / (1.0f + 0.3275911f * x);
float y = 1.0f - (((((1.061405429f * t + -1.453152027f) * t) + 1.421413741f)
* t + -0.284496736f) * t + 0.254829592f) * t * Mathf.Exp(-x * x);
return sign * y;
}
private static float ErfInv(float x)
{
float w, p;
w = -Mathf.Log((1.0f - x) * (1.0f + x));
if (w < 5.000000f)
{
w = w - 2.500000f;
p = 2.81022636e-08f;
p = 3.43273939e-07f + p * w;
p = -3.5233877e-06f + p * w;
p = -4.39150654e-06f + p * w;
p = 0.00021858087f + p * w;
p = -0.00125372503f + p * w;
p = -0.00417768164f + p * w;
p = 0.246640727f + p * w;
p = 1.50140941f + p * w;
}
else
{
w = Mathf.Sqrt(w) - 3.000000f;
p = -0.000200214257f;
p = 0.000100950558f + p * w;
p = 0.00134934322f + p * w;
p = -0.00367342844f + p * w;
p = 0.00573950773f + p * w;
p = -0.0076224613f + p * w;
p = 0.00943887047f + p * w;
p = 1.00167406f + p * w;
p = 2.83297682f + p * w;
}
return p * x;
}
private static float CDF(float x, float mu, float sigma)
{
float U = 0.5f * (1 + Erf((x - mu) / (sigma * Mathf.Sqrt(2.0f))));
return U;
}
private static float invCDF(float U, float mu, float sigma)
{
float x = sigma * Mathf.Sqrt(2.0f) * ErfInv(2.0f * U - 1.0f) + mu;
return x;
}
/*****************************************************************************/
/**** Section 1.3.2 Applying the histogram transformation T on the input *****/
/*****************************************************************************/
private struct PixelSortStruct
{
public int x;
public int y;
public float value;
};
private static void ComputeTinput(ref TextureData input, ref TextureData T_input, int channel)
{
// Sort pixels of example image
PixelSortStruct[] sortedInputValues = new PixelSortStruct[input.width * input.height];
for (int y = 0; y < input.height; y++)
for (int x = 0; x < input.width; x++)
{
sortedInputValues[y * input.width + x].x = x;
sortedInputValues[y * input.width + x].y = y;
sortedInputValues[y * input.width + x].value = input.GetColor(x, y)[channel];
}
System.Array.Sort(sortedInputValues, (x, y) => x.value.CompareTo(y.value));
// Assign Gaussian value to each pixel
for (uint i = 0; i < sortedInputValues.Length; i++)
{
// Pixel coordinates
int x = sortedInputValues[i].x;
int y = sortedInputValues[i].y;
// Input quantile (given by its order in the sorting)
float U = (i + 0.5f) / (sortedInputValues.Length);
// Gaussian quantile
float G = invCDF(U, GAUSSIAN_AVERAGE, GAUSSIAN_STD);
// Store
T_input.GetColorRef(x, y)[channel] = G;
}
}
/*****************************************************************************/
/* Section 1.3.3 Precomputing the inverse histogram transformation T^{-1} */
/*****************************************************************************/
private static void ComputeinvT(ref TextureData input, ref TextureData Tinv, int channel)
{
// Sort pixels of example image
float[] sortedInputValues = new float[input.width * input.height];
for (int y = 0; y < input.height; y++)
for (int x = 0; x < input.width; x++)
{
sortedInputValues[y * input.width + x] = input.GetColor(x, y)[channel];
}
System.Array.Sort(sortedInputValues);
// Generate Tinv look-up table
for (int i = 0; i < Tinv.width; i++)
{
// Gaussian value in [0, 1]
float G = (i + 0.5f) / (Tinv.width);
// Quantile value
float U = CDF(G, GAUSSIAN_AVERAGE, GAUSSIAN_STD);
// Find quantile in sorted pixel values
int index = (int)Mathf.Floor(U * sortedInputValues.Length);
// Get input value
float I = sortedInputValues[index];
// Store in LUT
Tinv.GetColorRef(i, 0)[channel] = I;
}
}
/*****************************************************************************/
/******** Section 1.4 Improvement: using a decorrelated color space **********/
/*****************************************************************************/
// Compute the eigen vectors of the histogram of the input
private static void ComputeEigenVectors(ref TextureData input, Vector3[] eigenVectors)
{
// First and second order moments
float R = 0, G = 0, B = 0, RR = 0, GG = 0, BB = 0, RG = 0, RB = 0, GB = 0;
for (int y = 0; y < input.height; y++)
{
for (int x = 0; x < input.width; x++)
{
Color col = input.GetColor(x, y);
R += col.r;
G += col.g;
B += col.b;
RR += col.r * col.r;
GG += col.g * col.g;
BB += col.b * col.b;
RG += col.r * col.g;
RB += col.r * col.b;
GB += col.g * col.b;
}
}
R /= (float)(input.width * input.height);
G /= (float)(input.width * input.height);
B /= (float)(input.width * input.height);
RR /= (float)(input.width * input.height);
GG /= (float)(input.width * input.height);
BB /= (float)(input.width * input.height);
RG /= (float)(input.width * input.height);
RB /= (float)(input.width * input.height);
GB /= (float)(input.width * input.height);
// Covariance matrix
double[][] covarMat = new double[3][];
for (int i = 0; i < 3; i++)
covarMat[i] = new double[3];
covarMat[0][0] = RR - R * R;
covarMat[0][1] = RG - R * G;
covarMat[0][2] = RB - R * B;
covarMat[1][0] = RG - R * G;
covarMat[1][1] = GG - G * G;
covarMat[1][2] = GB - G * B;
covarMat[2][0] = RB - R * B;
covarMat[2][1] = GB - G * B;
covarMat[2][2] = BB - B * B;
// Find eigen values and vectors using Jacobi algorithm
double[][] eigenVectorsTemp = new double[3][];
for (int i = 0; i < 3; i++)
eigenVectorsTemp[i] = new double[3];
double[] eigenValuesTemp = new double[3];
ComputeEigenValuesAndVectors(covarMat, eigenVectorsTemp, eigenValuesTemp);
// Set return values
eigenVectors[0] = new Vector3((float)eigenVectorsTemp[0][0], (float)eigenVectorsTemp[1][0], (float)eigenVectorsTemp[2][0]);
eigenVectors[1] = new Vector3((float)eigenVectorsTemp[0][1], (float)eigenVectorsTemp[1][1], (float)eigenVectorsTemp[2][1]);
eigenVectors[2] = new Vector3((float)eigenVectorsTemp[0][2], (float)eigenVectorsTemp[1][2], (float)eigenVectorsTemp[2][2]);
}
// ----------------------------------------------------------------------------
// Numerical diagonalization of 3x3 matrcies
// Copyright (C) 2006 Joachim Kopp
// ----------------------------------------------------------------------------
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
// ----------------------------------------------------------------------------
// Calculates the eigenvalues and normalized eigenvectors of a symmetric 3x3
// matrix A using the Jacobi algorithm.
// The upper triangular part of A is destroyed during the calculation,
// the diagonal elements are read but not destroyed, and the lower
// triangular elements are not referenced at all.
// ----------------------------------------------------------------------------
// Parameters:
// A: The symmetric input matrix
// Q: Storage buffer for eigenvectors
// w: Storage buffer for eigenvalues
// ----------------------------------------------------------------------------
// Return value:
// 0: Success
// -1: Error (no convergence)
private static int ComputeEigenValuesAndVectors(double[][] A, double[][] Q, double[] w)
{
const int n = 3;
double sd, so; // Sums of diagonal resp. off-diagonal elements
double s, c, t; // sin(phi), cos(phi), tan(phi) and temporary storage
double g, h, z, theta; // More temporary storage
double thresh;
// Initialize Q to the identitity matrix
for (int i = 0; i < n; i++)
{
Q[i][i] = 1.0;
for (int j = 0; j < i; j++)
Q[i][j] = Q[j][i] = 0.0;
}
// Initialize w to diag(A)
for (int i = 0; i < n; i++)
w[i] = A[i][i];
// Calculate SQR(tr(A))
sd = 0.0;
for (int i = 0; i < n; i++)
sd += System.Math.Abs(w[i]);
sd = sd * sd;
// Main iteration loop
for (int nIter = 0; nIter < 50; nIter++)
{
// Test for convergence
so = 0.0;
for (int p = 0; p < n; p++)
for (int q = p + 1; q < n; q++)
so += System.Math.Abs(A[p][q]);
if (so == 0.0)
return 0;
if (nIter < 4)
thresh = 0.2 * so / (n * n);
else
thresh = 0.0;
// Do sweep
for (int p = 0; p < n; p++)
{
for (int q = p + 1; q < n; q++)
{
g = 100.0 * System.Math.Abs(A[p][q]);
if (nIter > 4 && System.Math.Abs(w[p]) + g == System.Math.Abs(w[p])
&& System.Math.Abs(w[q]) + g == System.Math.Abs(w[q]))
{
A[p][q] = 0.0;
}
else if (System.Math.Abs(A[p][q]) > thresh)
{
// Calculate Jacobi transformation
h = w[q] - w[p];
if (System.Math.Abs(h) + g == System.Math.Abs(h))
{
t = A[p][q] / h;
}
else
{
theta = 0.5 * h / A[p][q];
if (theta < 0.0)
t = -1.0 / (System.Math.Sqrt(1.0 + (theta * theta)) - theta);
else
t = 1.0 / (System.Math.Sqrt(1.0 + (theta * theta)) + theta);
}
c = 1.0 / System.Math.Sqrt(1.0 + (t * t));
s = t * c;
z = t * A[p][q];
// Apply Jacobi transformation
A[p][q] = 0.0;
w[p] -= z;
w[q] += z;
for (int r = 0; r < p; r++)
{
t = A[r][p];
A[r][p] = c * t - s * A[r][q];
A[r][q] = s * t + c * A[r][q];
}
for (int r = p + 1; r < q; r++)
{
t = A[p][r];
A[p][r] = c * t - s * A[r][q];
A[r][q] = s * t + c * A[r][q];
}
for (int r = q + 1; r < n; r++)
{
t = A[p][r];
A[p][r] = c * t - s * A[q][r];
A[q][r] = s * t + c * A[q][r];
}
// Update eigenvectors
for (int r = 0; r < n; r++)
{
t = Q[r][p];
Q[r][p] = c * t - s * Q[r][q];
Q[r][q] = s * t + c * Q[r][q];
}
}
}
}
}
return -1;
}
// Main function of Section 1.4
private static void DecorrelateColorSpace(
ref TextureData input, // input: example image
ref TextureData input_decorrelated, // output: decorrelated input
ref Vector3 colorSpaceVector1, // output: color space vector1
ref Vector3 colorSpaceVector2, // output: color space vector2
ref Vector3 colorSpaceVector3, // output: color space vector3
ref Vector3 colorSpaceOrigin, // output: color space origin
string assetName)
{
// Compute the eigenvectors of the histogram
Vector3[] eigenvectors = new Vector3[3];
ComputeEigenVectors(ref input, eigenvectors);
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
// Rotate to eigenvector space
for (int y = 0; y < input.height; y++)
for (int x = 0; x < input.width; x++)
for (int channel = 0; channel < 3; ++channel)
{
// Get current color
Color color = input.GetColor(x, y);
Vector3 vec = new Vector3(color.r, color.g, color.b);
// Project on eigenvector
float new_channel_value = Vector3.Dot(vec, eigenvectors[channel]);
// Store
input_decorrelated.GetColorRef(x, y)[channel] = new_channel_value;
}
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
// Compute ranges of the new color space
Vector2[] colorSpaceRanges = new Vector2[3]{
new Vector2(float.MaxValue, float.MinValue),
new Vector2(float.MaxValue, float.MinValue),
new Vector2(float.MaxValue, float.MinValue) };
for (int y = 0; y < input.height; y++)
for (int x = 0; x < input.width; x++)
for (int channel = 0; channel < 3; ++channel)
{
colorSpaceRanges[channel].x = Mathf.Min(colorSpaceRanges[channel].x, input_decorrelated.GetColor(x, y)[channel]);
colorSpaceRanges[channel].y = Mathf.Max(colorSpaceRanges[channel].y, input_decorrelated.GetColor(x, y)[channel]);
}
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
// Remap range to [0, 1]
for (int y = 0; y < input.height; y++)
for (int x = 0; x < input.width; x++)
for (int channel = 0; channel < 3; ++channel)
{
// Get current value
float value = input_decorrelated.GetColor(x, y)[channel];
// Remap in [0, 1]
float remapped_value = (value - colorSpaceRanges[channel].x) / (colorSpaceRanges[channel].y - colorSpaceRanges[channel].x);
// Store
input_decorrelated.GetColorRef(x, y)[channel] = remapped_value;
}
EditorUtility.DisplayProgressBar("Pre-processing Procedural Texture Data", assetName, (float)stepCounter++ / (totalSteps - 1));
// Compute color space origin and vectors scaled for the normalized range
colorSpaceOrigin.x = colorSpaceRanges[0].x * eigenvectors[0].x + colorSpaceRanges[1].x * eigenvectors[1].x + colorSpaceRanges[2].x * eigenvectors[2].x;
colorSpaceOrigin.y = colorSpaceRanges[0].x * eigenvectors[0].y + colorSpaceRanges[1].x * eigenvectors[1].y + colorSpaceRanges[2].x * eigenvectors[2].y;
colorSpaceOrigin.z = colorSpaceRanges[0].x * eigenvectors[0].z + colorSpaceRanges[1].x * eigenvectors[1].z + colorSpaceRanges[2].x * eigenvectors[2].z;
colorSpaceVector1.x = eigenvectors[0].x * (colorSpaceRanges[0].y - colorSpaceRanges[0].x);
colorSpaceVector1.y = eigenvectors[0].y * (colorSpaceRanges[0].y - colorSpaceRanges[0].x);
colorSpaceVector1.z = eigenvectors[0].z * (colorSpaceRanges[0].y - colorSpaceRanges[0].x);
colorSpaceVector2.x = eigenvectors[1].x * (colorSpaceRanges[1].y - colorSpaceRanges[1].x);
colorSpaceVector2.y = eigenvectors[1].y * (colorSpaceRanges[1].y - colorSpaceRanges[1].x);
colorSpaceVector2.z = eigenvectors[1].z * (colorSpaceRanges[1].y - colorSpaceRanges[1].x);
colorSpaceVector3.x = eigenvectors[2].x * (colorSpaceRanges[2].y - colorSpaceRanges[2].x);
colorSpaceVector3.y = eigenvectors[2].y * (colorSpaceRanges[2].y - colorSpaceRanges[2].x);
colorSpaceVector3.z = eigenvectors[2].z * (colorSpaceRanges[2].y - colorSpaceRanges[2].x);
}
/*****************************************************************************/
/* ===== Section 1.5 Improvement: prefiltering the look-up table =========== */
/*****************************************************************************/
// Compute average subpixel variance at a given LOD
private static float ComputeLODAverageSubpixelVariance(ref TextureData image, int LOD, int channel)
{
// Window width associated with
int windowWidth = 1 << LOD;
// Compute average variance in all the windows
float average_window_variance = 0.0f;
// Loop over al the windows
for (int window_y = 0; window_y < image.height; window_y += windowWidth)
for (int window_x = 0; window_x < image.width; window_x += windowWidth)
{
// Estimate variance of current window
float v = 0.0f;
float v2 = 0.0f;
for (int y = 0; y < windowWidth; y++)
for (int x = 0; x < windowWidth; x++)
{
float value = image.GetColor(window_x + x, window_y + y)[channel];
v += value;
v2 += value * value;
}
v /= (float)(windowWidth * windowWidth);
v2 /= (float)(windowWidth * windowWidth);
float window_variance = Mathf.Max(0.0f, v2 - v * v);
// Update average
average_window_variance += window_variance / (image.width * image.height / windowWidth / windowWidth);
}
return average_window_variance;
}
// Filter LUT by sampling a Gaussian N(mu, std²)
private static float FilterLUTValueAtx(ref TextureData LUT, float x, float std, int channel)
{
// Number of samples for filtering (heuristic: twice the LUT resolution)
const int numberOfSamples = 2 * LUT_WIDTH;
// Filter
float filtered_value = 0.0f;
for (int sample = 0; sample < numberOfSamples; sample++)
{
// Quantile used to sample the Gaussian
float U = (sample + 0.5f) / numberOfSamples;
// Sample the Gaussian
float sample_x = invCDF(U, x, std);
// Find sample texel in LUT (the LUT covers the domain [0, 1])
int sample_texel = Mathf.Max(0, Mathf.Min(LUT_WIDTH - 1, (int)Mathf.Floor(sample_x * LUT_WIDTH)));
// Fetch LUT at level 0
float sample_value = LUT.GetColor(sample_texel, 0)[channel];
// Accumulate
filtered_value += sample_value;
}
// Normalize and return
filtered_value /= (float)numberOfSamples;
return filtered_value;
}
// Main function of section 1.5
private static void PrefilterLUT(ref TextureData image_T_Input, ref TextureData LUT_Tinv, int channel)
{
// Prefilter
for (int LOD = 1; LOD < LUT_Tinv.height; LOD++)
{
// Compute subpixel variance at LOD
float window_variance = ComputeLODAverageSubpixelVariance(ref image_T_Input, LOD, channel);
float window_std = Mathf.Sqrt(window_variance);
// Prefilter LUT with Gaussian kernel of this variance
for (int i = 0; i < LUT_Tinv.width; i++)
{
// Texel position in [0, 1]
float x_texel = (i + 0.5f) / LUT_Tinv.width;
// Filter look-up table around this position with Gaussian kernel
float filteredValue = FilterLUTValueAtx(ref LUT_Tinv, x_texel, window_std, channel);
// Store filtered value
LUT_Tinv.GetColorRef(i, LOD)[channel] = filteredValue;
}
}
}
}