Node questions for Plugin

[eikensson]

Hi

I am writing a plugin and it is working in the form of a command at the moment. Input mesh with multiple output meshes.

Now i wanna rewrite it as a node to create a more interactive workflow where my thought where to store the original mesh in the node at creation. The node would also keep track of the objects it creates.

I am fairly new to programming for the maya api and is having some trouble understanding how to setup a good layout for this.

Nodes are only computed when some of their output is marked as dirty. I would like a setup where a command triggers the node to recompute instead. At recompute it modifies the DG and deletes the old output objects and instead creates new. Is this possible? Or how can a similiar workflow be accomplished?

[joojaa]

I would like a setup where a command triggers the node to recompute instead.

err

settatr objectName.triggerAttribute

would do it.

The node would also keep track of the objects it creates.
Is this possible?

Well it doenst actually help you much since maya strictly speaking ASSUMES that no new node creation occours. Yes its possible but a bit futile on your part. You will scream at maya if you foce it into this mode. And i means seriously SCREAM!

Or how can a similiar workflow be accomplished?

To be totally honest what you want to do is make a shape node that then hides the facst that you do replication. So basically you just want to do is something a bit like the particle instancer but with editable meshes instead of actually having instances. Anyway such things are called boids.

[eikensson]

Ended up using blinddata to specify what objects part of mesh should belong to and then a new command that grabs the outmesh and creates the new objects from the blind data.

And dummy attributes with setAttr to only recompute when i want.

Now i am having some new problems in the command that creates new objects.

I am trying to assing per polygon shaders but all polygons get the same shader. None of my status checks reports any errors.

This is the code:

MFnSet shaderSet;  
MFnSet shaderSet2;

stat = shaderSet.setObject(innerSG);
std::cout << stat << std::endl;

stat = shaderSet2.setObject(outerSG);
std::cout << stat << std::endl;

MItMeshPolygon itPolygon(dagPathnewMesh);

for ( ;!itPolygon.isDone(); itPolygon.next() )
{
std::cout << objects[i].shader[itPolygon.index()] << std::endl;

MObject currentPoly = itPolygon.currentItem(&stat);
std::cout << "get poly object: " << stat << std::endl;
if(objects[i].shader[itPolygon.index()] !=-1)
{
stat = shaderSet.addMember(dagPathnewMesh, currentPoly);
std::cout << stat << std::endl;
 }
else
{
stat = shaderSet2.addMember(dagPathnewMesh, currentPoly);
std::cout << stat << std::endl;
 }

}

The first assigned shadinggroup to a polygon is the final result for all.

[joojaa]

I am trying to assing per polygon shaders but all polygons get the same shader.
None of my status checks reports any errors.

well its possibly better design to do that as somekind of per object data and let teh shaomg network sort it out, its also infinitely mroe easy to tweak.

[eikensson]

well its possibly better design to do that as somekind of per object data and let teh shaomg network sort it out, its also infinitely mroe

easy to tweak.

Could you please give some example. This was the only method i could find in the API and any examples of.