MpxNode merge input mesh and newpolygons

[stuzzz]

hello,

I have a MPxNode which has a mesh as an input attribute.

My output mesh attribute is a copy of the input but with a large amount of polygons created implemented in the MPxNode::compute() method.

for now my code is like this sample:

		MDataHandle inHld = data.inputValue(inMeshAttr);
		MObject inObj = inHld.asMesh();

		MDataHandle meshOutHdl = data.outputValue(outputAttr);

		meshOutHdl.copy(inHld);
		MFnMesh inMeshFn(meshOutHdl.asMesh());		
		
		MObject res= inMeshFn.create(numVerts, numpolys, vertarray, polycount, polyconn, inObj);
		inMeshFn.updateSurface();

		CHECK_MSTATUS(meshOutHdl.set(res));
	
		data.setClean(plug);

The problem is that my input mesh is replace with the newly created one.

I'd like to merge/append the resulting operation of MFnMesh::create() and my input shape.

I tought about MFnMesh::addPolygon but there is a ton of polys to create.

thx

[jmreinhart]

So could get all of this data from your input shape.

(numVerts, numpolys, vertarray, polycount, polyconn, inObj);

And then you'd go in and "offset" the indices in polyconn of your new data by adding the number of vertices in your original shape to each integer in your polyconn MIntarray. The you could just append the new data to the original data.

[stuzzz · Accepted solution]

Hey thanks for answering, I found my solution few hours ago, it's working. 

@jmreinhart indeed i took the same direction (append new datas to old one)

That's what I go so far:

MFnMesh meshFn(inObj);
meshFn.updateSurface();

// -- fetch input datas
int numverts2 = meshFn.numVertices();
int numpolys2 = meshFn.numPolygons();
MPointArray vertarray2;  meshFn.getPoints(vertarray2);
MIntArray polycount2; MIntArray polyconn2; meshFn.getVertices(polycount2, polyconn2);
	


// -- sum input datas with attribute datas
sumDatas(vertarray2, vertarray);
sumDatas(polycount2, polycount);
sumPolyconn(polyconn2, polyconn, numverts2);
appendNormals(normals, numverts);

// -- create new parentOwner
MFnMeshData meshDataFn;
MObject newMeshData = meshDataFn.create();
MFnMesh newFn(newMeshData);

newFn.create(
				numverts + numverts2, 
				numpolys + numpolys2, 
				vertarray2, 
				polycount2, 
				polyconn2, 
				newMeshData, 
				&stat);

if (!stat) { return MS::kInvalidParameter; }
newFn.updateSurface();

CHECK_MSTATUS(meshOutHdl.set(newMeshData));

The tricky thing is to get the correct owner and pass the valid data to the outputHandle.

I need to restore the UVs and edge hardness, then I'll be all set.

for some reason when I delete my node, the shape remain the still. I expected to have the previous shape back. I guess that I need to reevaluate the datablock or something