DAG node duplication issue in maya 2017

Anonymous · ‎05-31-2017

Hey, I've been developing a plugin for maya for a game project with a team of artists/designers. It started of with may 2016 but I need to port it to maya 2017 and I ran into a seemingly unexplainable issue.

we are using the maya Houdini plugin to generate the boundingbox and the final mesh for a racetrack but when we export a scene we want to get rid of all the extra Houdini stuff. so I wrote some code that would duplicate the boundingbox, then let Houdini generate the final mesh, and then duplicate that final mesh. the two duplicates are parented under the same root transform node created using a MDagModifier. in the below code the DagNode is the root of the Houdini digital asset.

// root node that will receive the duplicates
MObject rootTransform = mod.createNode("transform");
mod.doIt();

// copy over the bounding box
for (uint32_t i = 0; i < DAGnode.childCount(); i++)
{
	// the two shape nodes
	MFnDagNode sourceShape(digitalAssetTransform.child(i));

	duplicateBoundingBox(sourceShape, rootTransform);

	MDagPath path;
	sourceShape.getPath(path);
	path.extendToShape();
	ignoredShapes.push_back(path.node());
}

// set the houdini mesh type to generate the final mesh
type.setValue(2);

//copy over the final mesh
for (uint32_t i = 0; i < DAGnode.childCount(); i++)
{
	// the two shape nodes
	MFnDagNode sourceShape(digitalAssetTransform.child(i));
	
	duplicateFinalMesh(sourceShape, rootTransform);

	MDagPath path;
	sourceShape.getPath(path);
	path.extendToShape();

	ignoredShapes.push_back(path.node());
}

and here is the code for one of the duplicate functions

auto duplicateFinalMesh = [](MFnDagNode &sourceShape, MObject &parent = MObject::kNullObj)
{
	// the target node
	MDagModifier mod;
	MFnDagNode targetShape(sourceShape.duplicate());

	// add the right attributes to the shape
	targetShape.addAttribute(createObjectTypeAttr());
	targetShape.addAttribute(createEventsAttr());
	m_callbackIds.append(MNodeMessage::addAttributeChangedCallback(targetShape.object(), AttrChangedCB));
	m_callbackIds.append(MNodeMessage::addAttributeAddedOrRemovedCallback(targetShape.object(), AttrAddedOrRemovedCB));

	// extend the paths to the actual geometries
	MDagPath sourcePath;
	sourceShape.getPath(sourcePath);
	sourcePath.extendToShape();

	MDagPath targetPath;
	targetShape.getPath(targetPath);
	targetPath.extendToShape();

	//copy the shaders over to the new shape
	MoveShaders(sourcePath, targetPath);

	mod.reparentNode(targetShape.object(), parent);
	mod.doIt();
};

now, this code runs perfectly fine in maya 2016 but in maya 2017 both the boundingbox and final mesh are the same even though the code is exactly the same (all custom attributes do get duplicated correctly however). are there any suggestions on why this code behaves differently in maya 2016?

below are images of the different results.

cheng_xi_li · ‎06-05-2017

Hi stanpepels,

Can you send us detailed samples?

I am not very clear about your description. Shouldn't it be the same after duplication?

Yours,

Li