Add abstract InitNode

InitNode is an abstract class which is meant to be inherited
by all the initialization nodes (such as CameraInit), included
those that might be created by the user.

InitNode contains methods that can be reimplemented by the
children classes if necessary.

This abstract class allows to keep on using scripts such as
meshroom_batch without having to modify them specifically or
being limited to using a CameraInit node.

meshroom/nodes/aliceVision/CameraInit.py

@@ -8,7 +8,7 @@ import tempfile
 import logging
 
 from meshroom.core import desc, Version
-
+from meshroom.multiview import FilesByType, findFilesByTypeInFolder
 
 Viewpoint = [
     desc.IntParam(name="viewId", label="Id", description="Image UID", value=-1, uid=[0], range=None),
@@ -119,7 +119,8 @@ def readSfMData(sfmFile):
 
     return views, intrinsics
 
-class CameraInit(desc.CommandLineNode):
+
+class CameraInit(desc.CommandLineNode, desc.InitNode):
     commandLine = 'aliceVision_cameraInit {allParams} --allowSingleView 1' # don't throw an error if there is only one image
 
     size = desc.DynamicNodeSize('viewpoints')
@@ -250,6 +251,35 @@ The metadata needed are:
         ),
     ]
 
+    def __init__(self):
+        super(CameraInit, self).__init__()
+
+    def initialize(self, node, inputs, recursiveInputs):
+        # Reset graph inputs
+        self.resetAttributes(node, ["viewpoints", "intrinsics"])
+
+        filesByType = FilesByType()
+        searchedForImages = False
+
+        if recursiveInputs:
+            filesByType.extend(findFilesByTypeInFolder(recursiveInputs, recursive=True))
+            searchedForImages = True
+
+        # Add views and intrinsics from a file if it was provided, or look for the images
+        if len(inputs) == 1 and os.path.isfile(inputs[0]) and os.path.splitext(inputs[0])[-1] in ('.json', '.sfm'):
+            views, intrinsics = readSfMData(inputs[0])
+            self.extendAttributes(node, {"viewpoints": views, "intrinsics": intrinsics})
+        else:
+            filesByType.extend(findFilesByTypeInFolder(inputs, recursive=False))
+            searchedForImages = True
+
+        # If there was no input file, check that the directories do contain images
+        if searchedForImages and not filesByType.images:
+            raise ValueError("No valid input file or no image in the provided directories")
+
+        views, intrinsics = self.buildIntrinsics(node, filesByType.images)
+        self.setAttributes(node, {"viewpoints": views, "intrinsics": intrinsics})
+
     def upgradeAttributeValues(self, attrValues, fromVersion):
 
         # Starting with version 6, the principal point is now relative to the image center