Closestpointonmesh Node

[bendingiscool]

Hi, I'm having problems with the closest/nearestPointOnMesh (depending on Maya version). I want to collect the nearest face on the mesh to the locator. This is because I want to eventually be able to draw a curve on the surface and select the faces the curve goes over. The node returns a seemingly random 'closestFaceIndex' number, that is nowhere near the locator's posiiton. Below is what I have at mo...

// create closestPointOnMesh node
string $closestPoint = eval("createNode closestPointOnMesh -n cpom1");

//connect it to the polymesh
connectAttr -f pPlane1.outMesh ($closestPoint + ".inMesh");

//connect locator1 pos' to closestPointOnMesh pos'
connectAttr -f locator1.translateX cpom1.inPositionX;
connectAttr -f locator1.translateY cpom1.inPositionY;
connectAttr -f locator1.translateZ cpom1.inPositionZ;

//store face index
int $selectedFaces = getAttr cpom1.closestFaceIndex;

Has anyone had anyluck with this node, am I going about this the wrong way?

Any help/advice/suggestions would be very welcome

Many thanks,

Chris

[bendingiscool]

OK I have this so far, it loops through creating a locator in a random pos (for test purposes), then it makes a new 'nearestPointOnMesh' node each time and an int to grab the value of the 'faceIndex'.

Unfortunatly it seems to be averaging out the position and selecting the face in the middle of the locators, rather than grabbing each face as it goes through. Does anyone know what I'm doing wroung here?

for ($i=1;$i<5;$i++){
spaceLocator -p (rand(-10,10)) 0 (rand(-10,10)) -n ("locator" + $i);

    string $nearestPoint = `createNode nearestPointOnMesh -n ("npom" + $i)`;

    //connect it to the polymesh
    connectAttr -f pPlane1.worldMesh ($nearestPoint + ".inMesh");

    //connect locator1 pos' to nearestPointOnMesh pos'
    connectAttr -f (("locator" + $i) + ".translateX") (("npom" + $i) + ".inPositionX");
    connectAttr -f (("locator" + $i) + ".translateY") (("npom" + $i) + ".inPositionY");
    connectAttr -f (("locator" + $i) + ".translateZ") (("npom" + $i) + ".inPositionZ");

        //store face index
        int $selFaces = `getAttr (("npom" + $i) + ".nearestFaceIndex")`;
       
    select -add pPlane1.f[$selFaces];

}

Any input would be greatly apreciated,

Chris

[aen]

Hey Chris...
Your last post makes more sense.
The "nearestPointOnMesh" or any other node is just the same as any poly or nurb object once created. The node is not visible but in your "Outliner" -- Select "Display" and uncheck "DAG objects only" and now you can find your node object.
Select cNPOM and press and the Attribute Editor displays the node.
Look inside the "Result" tab and you have: Position, Normal, Parm UV and Nearest face index.

For what you want to do: Position would be the most accurate.

You must activate the "nearestPointOnMesh" plug-in the first time and then
createNode nearestPointOnMesh -n cNPOM; // will create the object "cNPOM"
If you now save your scene, cNPOM will be save to your scene file exactly the same as saving any poly you've created.
Reload this scene any time and the "nearestPointOnMesh" plug-in will autoload.

// So create a new scene
// Create a "sphere" called sphere, scale up and Modify: freeze transformations.
// Create a "sphere" called "driver" , scale down
// create a locator called "locator1" ,scale down...
// then run the coding below...
createNode nearestPointOnMesh -n cNPOM;
connectAttr -f sphereShape.outMesh cNPOM.inMesh;
connectAttr -f driver.translate cNPOM.inPosition;
connectAttr -f cNPOM.position locator1.translate;
// "driver" is your active 3D driver, move it around and "locator1" is the nearest position on the surface of the sphere

The code above is a dynamic nodal network, interactive and FAST. Your Node is now an independent dynamic structure and part of the scene's background. You write coding that is totally independently from this nodal structure (you seem to want to play with this -DO NOT TOUCH). In your coding move "driver" and then get "locator1's" translationXYZ to feed into your new locators.

I would suggest you research the connection editor and the hypergraph. I just used the connection editor to connected this node, And in the history pane of the Script Editor the above connectAttr lines of code appeared. I just copied and pasted them (I do this a lot, but some people actual memorize this stuff).

hth's aen

[bendingiscool]

Hey aen, thats a really handy insight, I will have to take your advice on that one.

Before I do get into trying it that way I would like to show a slighty revised version
of the one I have at the moment, as it seems to be getting closer.

I have revised the latest piece of code on the locator's movement.

When the loop is done it now selects the end one so it's getting there, now instead of
just selecting the end one how would I go about keeping each faceIndex selected, or
at least put in an array, so I can select the array once the loop has finished.

I promise to stop with the annoying questions, for a little while at least ; ) , if I can get this to work lol.

for ($i=1;$i<5;$i++){
spaceLocator -n ("locator" + $i);
move (rand(-10,10)) 0 (rand(-10,10));

// create nearestPointOnMesh node
//string $nearestPoint = eval("createNode nearestPointOnMesh -n npom1");

string $nearestPoint = createNode nearestPointOnMesh -n ("npom" + $i);

//connect it to the polymesh
connectAttr -f pPlane1.worldMesh ($nearestPoint + ".inMesh");

//connect locator1 pos' to nearestPointOnMesh pos'
connectAttr -f (("locator" + $i) + ".translateX") (("npom" + $i) + ".inPositionX");
connectAttr -f (("locator" + $i) + ".translateY") (("npom" + $i) + ".inPositionY");
connectAttr -f (("locator" + $i) + ".translateZ") (("npom" + $i) + ".inPositionZ");

//store face index
int $selFaces = getAttr (("npom" + $i) + ".nearestFaceIndex");

select -add pPlane1.f[$selFaces];
}

Many thanks,

Chris