/// <summary>
/// Prepare texture for importing
/// </summary>
void OnPreprocessTexture()
{
// Try to get import setting for the texture
var dimension = Texture3D.GetTilingDimension(assetPath);
if (dimension.x > 0 && dimension.y > 0)
{
var textureImporter = assetImporter as UnityEditor.TextureImporter;
if (textureImporter)
{
// Change import settings to 3D texture using the columns and rows
var settings = new UnityEditor.TextureImporterSettings();
textureImporter.ReadTextureSettings(settings);
settings.textureShape = UnityEditor.TextureImporterShape.Texture3D;
settings.flipbookColumns = dimension.x;
settings.flipbookRows = dimension.y;
settings.sRGBTexture = false;
settings.alphaSource = UnityEditor.TextureImporterAlphaSource.FromInput;
settings.alphaIsTransparency = true;
settings.mipmapEnabled = true;
settings.filterMode = FilterMode.Trilinear;
textureImporter.SetTextureSettings(settings);
}
}
}
/// <summary>
/// Exports the given texture to the destination texture path and wires up the preview surface.
/// </summary>
/// <returns>
/// Returns the path to the USD texture object.
/// </returns>
protected static string SetupTexture(Scene scene,
string usdShaderPath,
Material material,
PreviewSurfaceSample surface,
Vector4 scale,
string destTexturePath,
string textureName,
string textureOutput,
ConversionType conversionType = ConversionType.None)
{
// We have to handle multiple cases here:
// - file exists on disk
// - file is a supported format => can be directly copied
// - file is not in a supported format => need to blit / export
// - file is only in memory
// - a Texture2D
// - a Texture
// - a RenderTexture
// - needs special care if marked as Normal Map
// (can probably only be detected in an Editor context, and heuristically at runtime)
// => need to blit / export
// - file is not supported at all (or not yet)
// - a 3D texture
// => needs to be ignored, log Warning
bool textureIsExported = false;
string filePath = null;
string fileName = null;
var srcTexture2d = material.GetTexture(textureName);
bool needsConversion = false;
switch (conversionType)
{
case ConversionType.None:
break;
case ConversionType.UnpackNormal:
#if UNITY_EDITOR
if (UnityEditor.AssetDatabase.Contains(srcTexture2d))
{
// normal needs to be converted if the one on disk isn't really a normal map
// (e.g. created from greyscale)
UnityEditor.TextureImporter importer =
(UnityEditor.TextureImporter)UnityEditor.AssetImporter.GetAtPath(
UnityEditor.AssetDatabase.GetAssetPath(srcTexture2d));
if (importer.textureType != UnityEditor.TextureImporterType.NormalMap)
{
Debug.LogWarning("Texture " + textureName + " is set as NormalMap but isn't marked as such",
srcTexture2d);
}
UnityEditor.TextureImporterSettings dst = new UnityEditor.TextureImporterSettings();
importer.ReadTextureSettings(dst);
// if this NormalMap is created from greyscale we will export the NormalMap from memory.
if (dst.convertToNormalMap)
{
needsConversion = true;
break;
}
}
#endif
break;
default:
needsConversion = true;
break;
}
#if UNITY_EDITOR
// only export from disk if there's no need to do any type of data conversion here
if (!needsConversion)
{
var srcPath = UnityEditor.AssetDatabase.GetAssetPath(srcTexture2d);
if (!string.IsNullOrEmpty(srcPath))
{
#if UNITY_2019_2_OR_GREATER
// Since textures might be inside of packages for various reasons we should support that.
// Usually this would just be "Path.GetFullPath(srcPath)", but USD export messes with the CWD (Working Directory)
// and so we have to do a bit more path wrangling here.
if (srcPath.StartsWith("Packages"))
{
var pi = UnityEditor.PackageManager.PackageInfo.FindForAssetPath(srcPath);
srcPath = pi.resolvedPath + srcPath.Substring(("Packages/" + pi.name).Length);
}
#endif
if (srcPath.StartsWith("Assets"))
{
srcPath = Application.dataPath + "/" + srcPath.Substring("Assets/".Length);
}
fileName = System.IO.Path.GetFileName(srcPath);
filePath = System.IO.Path.Combine(destTexturePath, fileName);
if (System.IO.File.Exists(srcPath))
{
// USDZ officially only supports png / jpg / jpeg
// https://graphics.pixar.com/usd/docs/Usdz-File-Format-Specification.html
var ext = System.IO.Path.GetExtension(srcPath).ToLowerInvariant();
if (ext == ".png" || ext == ".jpg" || ext == ".jpeg")
{
System.IO.File.Copy(srcPath, filePath, overwrite: true);
if (System.IO.File.Exists(filePath))
{
textureIsExported = true;
}
}
}
}
}
#endif
if (!textureIsExported)
{
// Since this is a texture we can't directly export from disk, we need to blit it and output it as PNG.
// To avoid collisions, e.g. with multiple different textures named the same, each texture gets a pseudo-random name.
// This will also avoid collisions when exporting multiple models to the same folder, e.g. with a a RenderTexture called "RT"
// in each of them that might look different between exports.
// TODO Future work could, if necessary, generate a texture content hash to avoid exporting identical textures multiple times
// (Unity's content hash isn't reliable for some types of textures unfortunately, e.g. RTs)
#if UNITY_EDITOR
if (srcTexture2d is Texture2D)
{
fileName = srcTexture2d.name + "_" + srcTexture2d.imageContentsHash.ToString();
}
else
{
fileName = srcTexture2d.name + "_" + Random.Range(10000000, 99999999).ToString();
}
#else
fileName = srcTexture2d.name + "_" + Random.Range(10000000, 99999999).ToString();
#endif
filePath = System.IO.Path.Combine(destTexturePath, fileName + ".png");
// TODO extra care has to be taken of Normal Maps etc., since these are in a converted format in memory (for example 16 bit AG instead of 8 bit RGBA, depending on platform)
// An example of this conversion in a shader is in Khronos' UnityGLTF implementation.
// Basically, the blit has do be done with the right unlit conversion shader to get a proper "file-based" tangent space normal map back
// Blit the texture and get it back to CPU
// Note: Can't use RenderTexture.GetTemporary because that doesn't properly clear alpha channel
bool preserveLinear = false;
switch (conversionType)
{
case ConversionType.UnpackNormal:
preserveLinear = true;
break;
}
var rt = new RenderTexture(srcTexture2d.width, srcTexture2d.height, 0, RenderTextureFormat.ARGB32,
preserveLinear ? RenderTextureReadWrite.Linear : RenderTextureReadWrite.Default);
var resultTex2d = new Texture2D(srcTexture2d.width, srcTexture2d.height, TextureFormat.ARGB32, true,
preserveLinear ? true : false);
var activeRT = RenderTexture.active;
try
{
RenderTexture.active = rt;
GL.Clear(true, true, Color.clear);
// conversion material
if (_metalGlossChannelSwapMaterial == null)
{
_metalGlossChannelSwapMaterial = new Material(Shader.Find("Hidden/USD/ChannelCombiner"));
}
if (_normalChannelMaterial == null)
{
_normalChannelMaterial = new Material(Shader.Find("Hidden/USD/NormalChannel"));
}
_metalGlossChannelSwapMaterial.SetTexture("_R", srcTexture2d);
_metalGlossChannelSwapMaterial.SetTexture("_G", srcTexture2d);
_metalGlossChannelSwapMaterial.SetTexture("_B", srcTexture2d);
_metalGlossChannelSwapMaterial.SetTexture("_A", srcTexture2d);
switch (conversionType)
{
case ConversionType.None:
Graphics.Blit(srcTexture2d, rt);
break;
case ConversionType.SwapRASmoothnessToBGRoughness:
_metalGlossChannelSwapMaterial.SetVector("_Invert",
new Vector4(0, 1, 0, 1)); // invert resulting g channel, make sure alpha is 1
_metalGlossChannelSwapMaterial.SetVector("_RScale", new Vector4(0, 0, 0, 0));
_metalGlossChannelSwapMaterial.SetVector("_GScale",
new Vector4(0, 0, 0, 1)); // use a channel from _G texture for resulting g
_metalGlossChannelSwapMaterial.SetVector("_BScale",
new Vector4(1, 0, 0, 0)); // use r channel from _B texture for resulting b
_metalGlossChannelSwapMaterial.SetVector("_AScale", new Vector4(0, 0, 0, 0));
Graphics.Blit(srcTexture2d, rt, _metalGlossChannelSwapMaterial);
break;
case ConversionType.InvertAlpha:
_metalGlossChannelSwapMaterial.SetVector("_Invert",
new Vector4(0, 0, 0, 1)); // invert alpha result
_metalGlossChannelSwapMaterial.SetVector("_RScale",
new Vector4(1, 0, 0, 0)); // use all color channels as-is
_metalGlossChannelSwapMaterial.SetVector("_GScale", new Vector4(0, 1, 0, 0));
_metalGlossChannelSwapMaterial.SetVector("_BScale", new Vector4(0, 0, 1, 0));
_metalGlossChannelSwapMaterial.SetVector("_AScale", new Vector4(0, 0, 0, 1));
Graphics.Blit(srcTexture2d, rt, _metalGlossChannelSwapMaterial);
break;
case ConversionType.MaskMapToORM:
// Input is RGBA (Metallic, Occlusion, Detail, Smoothness)
// Output is RGB1 (Occlusion, Roughness = 1 - Smoothness, Metallic, 1)
_metalGlossChannelSwapMaterial.SetVector("_Invert",
new Vector4(0, 1, 0, 1)); // smoothness to roughness, solid alpha
_metalGlossChannelSwapMaterial.SetVector("_RScale", new Vector4(0, 1, 0, 0));
_metalGlossChannelSwapMaterial.SetVector("_GScale", new Vector4(0, 0, 0, 1));
_metalGlossChannelSwapMaterial.SetVector("_BScale", new Vector4(1, 0, 0, 0));
_metalGlossChannelSwapMaterial.SetVector("_AScale", new Vector4(0, 0, 0, 0));
Graphics.Blit(srcTexture2d, rt, _metalGlossChannelSwapMaterial);
break;
case ConversionType.UnpackNormal:
Graphics.Blit(srcTexture2d, rt, _normalChannelMaterial);
break;
}
resultTex2d.ReadPixels(new Rect(0, 0, srcTexture2d.width, srcTexture2d.height), 0, 0);
resultTex2d.Apply();
System.IO.File.WriteAllBytes(filePath, resultTex2d.EncodeToPNG());
if (System.IO.File.Exists(filePath))
{
textureIsExported = true;
}
}
finally
{
RenderTexture.active = activeRT;
rt.Release();
GameObject.DestroyImmediate(rt);
GameObject.DestroyImmediate(resultTex2d);
}
}
if (!textureIsExported)
{
var tmpTex2d = new Texture2D(1, 1, TextureFormat.ARGB32, true);
try
{
tmpTex2d.SetPixel(0, 0, Color.white);
tmpTex2d.Apply();
System.IO.File.WriteAllBytes(filePath, tmpTex2d.EncodeToPNG());
if (System.IO.File.Exists(filePath))
{
textureIsExported = true;
}
}
finally
{
GameObject.DestroyImmediate(tmpTex2d);
}
}
if (textureIsExported)
{
// Make file path baked into USD relative to scene file and use forward slashes.
filePath = ImporterBase.MakeRelativePath(scene.FilePath, filePath);
filePath = filePath.Replace("\\", "/");
var uvReader = new PrimvarReaderSample <Vector2>();
uvReader.varname.defaultValue = new TfToken("st");
scene.Write(usdShaderPath + "/uvReader", uvReader);
var usdTexReader = new TextureReaderSample(filePath, usdShaderPath + "/uvReader.outputs:result");
usdTexReader.wrapS =
new Connectable <TextureReaderSample.WrapMode>(
TextureReaderSample.GetWrapMode(srcTexture2d.wrapModeU));
usdTexReader.wrapT =
new Connectable <TextureReaderSample.WrapMode>(
TextureReaderSample.GetWrapMode(srcTexture2d.wrapModeV));
if (scale != Vector4.one)
{
usdTexReader.scale = new Connectable <Vector4>(scale);
}
// usdTexReader.isSRGB = new Connectable<TextureReaderSample.SRGBMode>(TextureReaderSample.SRGBMode.Auto);
scene.Write(usdShaderPath + "/" + textureName, usdTexReader);
return(usdShaderPath + "/" + textureName + ".outputs:" + textureOutput);
}
else
{
Debug.LogError(
"Texture wasn't exported: " + srcTexture2d.name + " (" + textureName + " from material " + material,
srcTexture2d);
return(null);
}
}
