Files
test/tests/python/bl_usd_export_test.py
Jesse Yurkovich 9daded5d87 USD: Use nodes for alpha-clip behavior instead of material properties
EEVEE-next has removed the MA_BM_CLIP / alpha_threshold material
properties in favor of using nodes for equivalent functionality. This
changes USD to build and traverse node graphs during import and export
accordingly. Indirectly this allows Cycles to correctly render such
materials now too.

A complicating factor is that the UsdPreviewSurface defines its opacity
threshold using greater-than-equals[1], which Blender does not support
(and for which was technically already incorrect as EEVEE-legacy only
used greater-than for its shaders). Due to this we actually need to use
2 nodes: A less-than, followed by a one-minus invert, to arrive at the
proper value. We'll translate UsdPreviewSurface to this form on Import.

For Export we will look for either this 2-node pattern or a Round
node plugged into Alpha. Looking for Round is a result of the glTF
documentation which recommended the use of this node for thresholds of
0.5[2]. It's a tiny addition that seems reasonable to accommodate.

[1] https://openusd.org/release/spec_usdpreviewsurface.html (search for "opacityThreshold")
[2] https://docs.blender.org/manual/en/4.2/addons/import_export/scene_gltf2.html#alpha-modes

See PR for example images

Pull Request: https://projects.blender.org/blender/blender/pulls/122025
2024-05-25 23:30:13 +02:00

303 lines
14 KiB
Python

# SPDX-FileCopyrightText: 2023 Blender Authors
#
# SPDX-License-Identifier: GPL-2.0-or-later
import pathlib
import pprint
import sys
import tempfile
import unittest
from pxr import Usd
from pxr import UsdUtils
from pxr import UsdGeom
from pxr import UsdShade
from pxr import Gf
import bpy
args = None
class AbstractUSDTest(unittest.TestCase):
@classmethod
def setUpClass(cls):
cls._tempdir = tempfile.TemporaryDirectory()
cls.testdir = args.testdir
cls.tempdir = pathlib.Path(cls._tempdir.name)
return cls
def setUp(self):
self.assertTrue(
self.testdir.exists(), "Test dir {0} should exist".format(self.testdir)
)
def tearDown(self):
self._tempdir.cleanup()
class USDExportTest(AbstractUSDTest):
def test_export_usdchecker(self):
"""Test exporting a scene and verifying it passes the usdchecker test suite"""
bpy.ops.wm.open_mainfile(
filepath=str(self.testdir / "usd_materials_export.blend")
)
export_path = self.tempdir / "usdchecker.usda"
res = bpy.ops.wm.usd_export(
filepath=str(export_path),
export_materials=True,
evaluation_mode="RENDER",
)
self.assertEqual({'FINISHED'}, res, f"Unable to export to {export_path}")
checker = UsdUtils.ComplianceChecker(
arkit=False,
skipARKitRootLayerCheck=False,
rootPackageOnly=False,
skipVariants=False,
verbose=False,
)
checker.CheckCompliance(str(export_path))
failed_checks = {}
# The ComplianceChecker does not know how to resolve <UDIM> tags, so
# it will flag "textures/test_grid_<UDIM>.png" as a missing reference.
# That reference is in fact OK, so we skip the rule for this test.
to_skip = ("MissingReferenceChecker",)
for rule in checker._rules:
name = rule.__class__.__name__
if name in to_skip:
continue
issues = rule.GetFailedChecks() + rule.GetWarnings() + rule.GetErrors()
if not issues:
continue
failed_checks[name] = issues
self.assertFalse(failed_checks, pprint.pformat(failed_checks))
def compareVec3d(self, first, second):
places = 5
self.assertAlmostEqual(first[0], second[0], places)
self.assertAlmostEqual(first[1], second[1], places)
self.assertAlmostEqual(first[2], second[2], places)
def test_export_extents(self):
"""Test that exported scenes contain have a properly authored extent attribute on each boundable prim"""
bpy.ops.wm.open_mainfile(filepath=str(self.testdir / "usd_extent_test.blend"))
export_path = self.tempdir / "usd_extent_test.usda"
res = bpy.ops.wm.usd_export(
filepath=str(export_path),
export_materials=True,
evaluation_mode="RENDER",
)
self.assertEqual({'FINISHED'}, res, f"Unable to export to {export_path}")
# if prims are missing, the exporter must have skipped some objects
stats = UsdUtils.ComputeUsdStageStats(str(export_path))
self.assertEqual(stats["totalPrimCount"], 16, "Unexpected number of prims")
# validate the overall world bounds of the scene
stage = Usd.Stage.Open(str(export_path))
scenePrim = stage.GetPrimAtPath("/root/scene")
bboxcache = UsdGeom.BBoxCache(Usd.TimeCode.Default(), [UsdGeom.Tokens.default_])
bounds = bboxcache.ComputeWorldBound(scenePrim)
bound_min = bounds.GetRange().GetMin()
bound_max = bounds.GetRange().GetMax()
self.compareVec3d(bound_min, Gf.Vec3d(-5.752975881, -1, -2.798513651))
self.compareVec3d(bound_max, Gf.Vec3d(1, 2.9515805244, 2.7985136508))
# validate the locally authored extents
prim = stage.GetPrimAtPath("/root/scene/BigCube/BigCubeMesh")
extent = UsdGeom.Boundable(prim).GetExtentAttr().Get()
self.compareVec3d(Gf.Vec3d(extent[0]), Gf.Vec3d(-1, -1, -2.7985137))
self.compareVec3d(Gf.Vec3d(extent[1]), Gf.Vec3d(1, 1, 2.7985137))
prim = stage.GetPrimAtPath("/root/scene/LittleCube/LittleCubeMesh")
extent = UsdGeom.Boundable(prim).GetExtentAttr().Get()
self.compareVec3d(Gf.Vec3d(extent[0]), Gf.Vec3d(-1, -1, -1))
self.compareVec3d(Gf.Vec3d(extent[1]), Gf.Vec3d(1, 1, 1))
prim = stage.GetPrimAtPath("/root/scene/Volume/Volume")
extent = UsdGeom.Boundable(prim).GetExtentAttr().Get()
self.compareVec3d(
Gf.Vec3d(extent[0]), Gf.Vec3d(-0.7313742, -0.68043584, -0.5801515)
)
self.compareVec3d(
Gf.Vec3d(extent[1]), Gf.Vec3d(0.7515701, 0.5500924, 0.9027928)
)
def test_opacity_threshold(self):
# Note that the scene file used here is shared with a different test.
# Here we assume that it has a Principled BSDF material with
# a texture connected to its Base Color input.
bpy.ops.wm.open_mainfile(filepath=str(self.testdir / "usd_materials_export.blend"))
export_path = self.tempdir / "opaque_material.usda"
res = bpy.ops.wm.usd_export(
filepath=str(export_path),
export_materials=True,
evaluation_mode="RENDER",
)
self.assertEqual({'FINISHED'}, res, f"Unable to export to {export_path}")
# Inspect and validate the exported USD for the opaque blend case.
stage = Usd.Stage.Open(str(export_path))
shader_prim = stage.GetPrimAtPath("/root/_materials/Material/Principled_BSDF")
shader = UsdShade.Shader(shader_prim)
opacity_input = shader.GetInput('opacity')
self.assertEqual(opacity_input.HasConnectedSource(), False,
"Opacity input should not be connected for opaque material")
self.assertAlmostEqual(opacity_input.Get(), 1.0, 2, "Opacity input should be set to 1")
# Inspect and validate the exported USD for the alpha clip w/Round node case.
shader_prim = stage.GetPrimAtPath("/root/_materials/Clip_With_Round/Principled_BSDF")
shader = UsdShade.Shader(shader_prim)
opacity_input = shader.GetInput('opacity')
opacity_thresh_input = shader.GetInput('opacityThreshold')
self.assertEqual(opacity_input.HasConnectedSource(), True, "Alpha input should be connected")
self.assertAlmostEqual(opacity_thresh_input.Get(), 0.5, 2, "Opacity threshold input should be 0.5")
# Inspect and validate the exported USD for the alpha clip w/LessThan+Invert node case.
shader_prim = stage.GetPrimAtPath("/root/_materials/Clip_With_LessThanInvert/Principled_BSDF")
shader = UsdShade.Shader(shader_prim)
opacity_input = shader.GetInput('opacity')
opacity_thresh_input = shader.GetInput('opacityThreshold')
self.assertEqual(opacity_input.HasConnectedSource(), True, "Alpha input should be connected")
self.assertAlmostEqual(opacity_thresh_input.Get(), 0.2, 2, "Opacity threshold input should be 0.2")
def check_primvar(self, prim, pv_name, pv_typeName, pv_interp, elements_len):
pv = UsdGeom.PrimvarsAPI(prim).GetPrimvar(pv_name)
self.assertTrue(pv.HasValue())
self.assertEqual(pv.GetTypeName().type.typeName, pv_typeName)
self.assertEqual(pv.GetInterpolation(), pv_interp)
self.assertEqual(len(pv.Get()), elements_len)
def check_primvar_missing(self, prim, pv_name):
pv = UsdGeom.PrimvarsAPI(prim).GetPrimvar(pv_name)
self.assertFalse(pv.HasValue())
def test_export_attributes(self):
bpy.ops.wm.open_mainfile(filepath=str(self.testdir / "usd_attribute_test.blend"))
export_path = self.tempdir / "usd_attribute_test.usda"
res = bpy.ops.wm.usd_export(filepath=str(export_path), evaluation_mode="RENDER")
self.assertEqual({'FINISHED'}, res, f"Unable to export to {export_path}")
stage = Usd.Stage.Open(str(export_path))
# Validate all expected Mesh attributes. Notice that nothing on
# the Edge domain is supported by USD.
prim = stage.GetPrimAtPath("/root/Mesh/Mesh")
self.check_primvar(prim, "p_bool", "VtArray<bool>", "vertex", 4)
self.check_primvar(prim, "p_int8", "VtArray<int>", "vertex", 4)
self.check_primvar(prim, "p_int32", "VtArray<int>", "vertex", 4)
self.check_primvar(prim, "p_float", "VtArray<float>", "vertex", 4)
self.check_primvar(prim, "p_color", "VtArray<GfVec3f>", "vertex", 4)
self.check_primvar(prim, "p_byte_color", "VtArray<GfVec3f>", "vertex", 4)
self.check_primvar(prim, "p_vec2", "VtArray<GfVec2f>", "vertex", 4)
self.check_primvar(prim, "p_vec3", "VtArray<GfVec3f>", "vertex", 4)
self.check_primvar(prim, "p_quat", "VtArray<GfQuatf>", "vertex", 4)
self.check_primvar_missing(prim, "p_mat4x4")
self.check_primvar_missing(prim, "e_bool")
self.check_primvar_missing(prim, "e_int8")
self.check_primvar_missing(prim, "e_int32")
self.check_primvar_missing(prim, "e_float")
self.check_primvar_missing(prim, "e_color")
self.check_primvar_missing(prim, "e_byte_color")
self.check_primvar_missing(prim, "e_vec2")
self.check_primvar_missing(prim, "e_vec3")
self.check_primvar_missing(prim, "e_quat")
self.check_primvar_missing(prim, "e_mat4x4")
self.check_primvar(prim, "f_bool", "VtArray<bool>", "uniform", 1)
self.check_primvar(prim, "f_int8", "VtArray<int>", "uniform", 1)
self.check_primvar(prim, "f_int32", "VtArray<int>", "uniform", 1)
self.check_primvar(prim, "f_float", "VtArray<float>", "uniform", 1)
self.check_primvar_missing(prim, "f_color")
self.check_primvar_missing(prim, "f_byte_color")
self.check_primvar(prim, "f_vec2", "VtArray<GfVec2f>", "uniform", 1)
self.check_primvar(prim, "f_vec3", "VtArray<GfVec3f>", "uniform", 1)
self.check_primvar(prim, "f_quat", "VtArray<GfQuatf>", "uniform", 1)
self.check_primvar_missing(prim, "f_mat4x4")
self.check_primvar(prim, "fc_bool", "VtArray<bool>", "faceVarying", 4)
self.check_primvar(prim, "fc_int8", "VtArray<int>", "faceVarying", 4)
self.check_primvar(prim, "fc_int32", "VtArray<int>", "faceVarying", 4)
self.check_primvar(prim, "fc_float", "VtArray<float>", "faceVarying", 4)
self.check_primvar(prim, "fc_color", "VtArray<GfVec3f>", "faceVarying", 4)
self.check_primvar(prim, "fc_byte_color", "VtArray<GfVec3f>", "faceVarying", 4)
self.check_primvar(prim, "fc_vec2", "VtArray<GfVec2f>", "faceVarying", 4)
self.check_primvar(prim, "fc_vec3", "VtArray<GfVec3f>", "faceVarying", 4)
self.check_primvar(prim, "fc_quat", "VtArray<GfQuatf>", "faceVarying", 4)
self.check_primvar_missing(prim, "fc_mat4x4")
prim = stage.GetPrimAtPath("/root/Curve_base/Curves/Curves")
self.check_primvar(prim, "p_bool", "VtArray<bool>", "vertex", 24)
self.check_primvar(prim, "p_int8", "VtArray<int>", "vertex", 24)
self.check_primvar(prim, "p_int32", "VtArray<int>", "vertex", 24)
self.check_primvar(prim, "p_float", "VtArray<float>", "vertex", 24)
self.check_primvar_missing(prim, "p_color")
self.check_primvar_missing(prim, "p_byte_color")
self.check_primvar(prim, "p_vec2", "VtArray<GfVec2f>", "vertex", 24)
self.check_primvar(prim, "p_vec3", "VtArray<GfVec3f>", "vertex", 24)
self.check_primvar(prim, "p_quat", "VtArray<GfQuatf>", "vertex", 24)
self.check_primvar_missing(prim, "p_mat4x4")
self.check_primvar(prim, "sp_bool", "VtArray<bool>", "uniform", 2)
self.check_primvar(prim, "sp_int8", "VtArray<int>", "uniform", 2)
self.check_primvar(prim, "sp_int32", "VtArray<int>", "uniform", 2)
self.check_primvar(prim, "sp_float", "VtArray<float>", "uniform", 2)
self.check_primvar_missing(prim, "sp_color")
self.check_primvar_missing(prim, "sp_byte_color")
self.check_primvar(prim, "sp_vec2", "VtArray<GfVec2f>", "uniform", 2)
self.check_primvar(prim, "sp_vec3", "VtArray<GfVec3f>", "uniform", 2)
self.check_primvar(prim, "sp_quat", "VtArray<GfQuatf>", "uniform", 2)
self.check_primvar_missing(prim, "sp_mat4x4")
prim = stage.GetPrimAtPath("/root/Curve_bezier_base/Curves_bezier/Curves")
self.check_primvar(prim, "p_bool", "VtArray<bool>", "varying", 10)
self.check_primvar(prim, "p_int8", "VtArray<int>", "varying", 10)
self.check_primvar(prim, "p_int32", "VtArray<int>", "varying", 10)
self.check_primvar(prim, "p_float", "VtArray<float>", "varying", 10)
self.check_primvar_missing(prim, "p_color")
self.check_primvar_missing(prim, "p_byte_color")
self.check_primvar(prim, "p_vec2", "VtArray<GfVec2f>", "varying", 10)
self.check_primvar(prim, "p_vec3", "VtArray<GfVec3f>", "varying", 10)
self.check_primvar(prim, "p_quat", "VtArray<GfQuatf>", "varying", 10)
self.check_primvar_missing(prim, "p_mat4x4")
self.check_primvar(prim, "sp_bool", "VtArray<bool>", "uniform", 3)
self.check_primvar(prim, "sp_int8", "VtArray<int>", "uniform", 3)
self.check_primvar(prim, "sp_int32", "VtArray<int>", "uniform", 3)
self.check_primvar(prim, "sp_float", "VtArray<float>", "uniform", 3)
self.check_primvar_missing(prim, "sp_color")
self.check_primvar_missing(prim, "sp_byte_color")
self.check_primvar(prim, "sp_vec2", "VtArray<GfVec2f>", "uniform", 3)
self.check_primvar(prim, "sp_vec3", "VtArray<GfVec3f>", "uniform", 3)
self.check_primvar(prim, "sp_quat", "VtArray<GfQuatf>", "uniform", 3)
self.check_primvar_missing(prim, "sp_mat4x4")
def main():
global args
import argparse
if "--" in sys.argv:
argv = [sys.argv[0]] + sys.argv[sys.argv.index("--") + 1:]
else:
argv = sys.argv
parser = argparse.ArgumentParser()
parser.add_argument("--testdir", required=True, type=pathlib.Path)
args, remaining = parser.parse_known_args(argv)
unittest.main(argv=remaining)
if __name__ == "__main__":
main()