feat(nuke): adding collect backdrop plugin

pype/plugins/nuke/publish/collect_nukenodes.py

@@ -0,0 +1,34 @@
+import pyblish.api
+import nuke
+
+class CollectBackdrops(pyblish.api.InstancePlugin):
+    """Collect Backdrop instance from rendered frames
+    """
+
+    order = pyblish.api.CollectorOrder + 0.3
+    label = "Collect Backdrop"
+    hosts = ["nuke"]
+    families = ["nukenodes"]
+
+    def process(self, instance):
+
+        bckn = instance[0]
+
+        left = bckn.xpos()
+        top = bckn.ypos()
+        right = left + bckn['bdwidth'].value()
+        bottom = top + bckn['bdheight'].value()
+
+        inNodes = []
+        for node in nuke.allNodes():
+            if node.Class() == "Viewer":
+                continue
+
+            if (node.xpos() > left) \
+                and (node.xpos() + node.screenWidth() < right) \
+                    and (node.ypos() > top) \
+                    and (node.ypos() + node.screenHeight() < bottom):
+                inNodes.append(node)
+
+        self.log.info("Backdrop content collected: `{}`".format(inNodes))
+        self.log.info("Backdrop instance collected: `{}`".format(instance))