Eevee: add regression tests.

This adds Eevee render tests using the Cycles files. Currently it must
be enabled by setting WITH_OPENGL_RENDER_TESTS=ON. Once we have reference
images we can enable it by default.

Some of the Cycles and Eevee tests are also currently broken due to
modifier and particle changes.

Differential Revision: https://developer.blender.org/D3182

tests/python/eevee_render_tests.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+# Apache License, Version 2.0
+
+import argparse
+import os
+import shlex
+import shutil
+import subprocess
+import sys
+
+def setup():
+    import bpy
+
+    # Enable Eevee features
+    scene = bpy.context.scene
+    eevee = scene.eevee
+
+    eevee.sss_enable = True
+    eevee.ssr_enable = True
+    eevee.ssr_refraction = True
+    eevee.gtao_enable = True
+    eevee.dof_enable = True
+
+    eevee.volumetric_enable = True
+    eevee.volumetric_shadows = True
+    eevee.volumetric_tile_size = '2'
+
+    for mat in bpy.data.materials:
+        mat.use_screen_refraction = True
+        mat.use_screen_subsurface = True
+
+# When run from inside Blender, render and exit.
+try:
+    import bpy
+    inside_blender = True
+except ImportError:
+    inside_blender = False
+
+if inside_blender:
+    try:
+        setup()
+    except Exception as e:
+        print(e)
+        sys.exit(1)
+
+
+def render_file(filepath, output_filepath):
+    dirname = os.path.dirname(filepath)
+    basedir = os.path.dirname(dirname)
+    subject = os.path.basename(dirname)
+
+    frame_filepath = output_filepath + '0001.png'
+
+    command = [
+        BLENDER,
+        "--background",
+        "-noaudio",
+        "--factory-startup",
+        "--enable-autoexec",
+        filepath,
+        "-E", "BLENDER_EEVEE",
+        "-P",
+        os.path.realpath(__file__),
+        "-o", output_filepath,
+        "-F", "PNG",
+        "-f", "1"]
+
+    try:
+        # Success
+        output = subprocess.check_output(command)
+        if os.path.exists(frame_filepath):
+            shutil.copy(frame_filepath, output_filepath)
+            os.remove(frame_filepath)
+        if VERBOSE:
+            print(" ".join(command))
+            print(output.decode("utf-8"))
+        return None
+    except subprocess.CalledProcessError as e:
+        # Error
+        if os.path.exists(frame_filepath):
+            os.remove(frame_filepath)
+        if VERBOSE:
+            print(" ".join(command))
+            print(e.output.decode("utf-8"))
+        if b"Error: engine not found" in e.output:
+            return "NO_ENGINE"
+        elif b"blender probably wont start" in e.output:
+            return "NO_START"
+        return "CRASH"
+    except BaseException as e:
+        # Crash
+        if os.path.exists(frame_filepath):
+            os.remove(frame_filepath)
+        if VERBOSE:
+            print(" ".join(command))
+            print(e)
+        return "CRASH"
+
+
+def create_argparse():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("-blender", nargs="+")
+    parser.add_argument("-testdir", nargs=1)
+    parser.add_argument("-outdir", nargs=1)
+    parser.add_argument("-idiff", nargs=1)
+    return parser
+
+
+def main():
+    parser = create_argparse()
+    args = parser.parse_args()
+
+    global BLENDER, VERBOSE
+
+    BLENDER = args.blender[0]
+    VERBOSE = os.environ.get("BLENDER_VERBOSE") is not None
+
+    test_dir = args.testdir[0]
+    idiff = args.idiff[0]
+    output_dir = args.outdir[0]
+
+    from modules import render_report
+    report = render_report.Report("Eevee Test Report", output_dir, idiff)
+    report.set_pixelated(True)
+    report.set_reference_dir("eevee_renders")
+    ok = report.run(test_dir, render_file)
+
+    sys.exit(not ok)
+
+
+if not inside_blender and __name__ == "__main__":
+    main()