From AbstractMesh to Mesh

[Aidoru]

Hello everyone,
I have a little problem:
I would like to use CSG on mesh imported using assetsmanager, everythins work ok but I cant reach to have a CSG object, that I think it's because I have an abstractmesh and not a mesh,
So how to convert AbstractMesh to mesh? My bad part of code is that:

assetsManager.onFinish = function(task)
        {
            var prova = task[0].loadedMeshes[0];
            aCSG = BABYLON.CSG.FromMesh(prova);

I get "Cannot read property '0' of null", that I think because loadeMeshes return an Array<AbstractMesh> as the documentation here:  https://doc.babylonjs.com/api/classes/babylon.meshassettask#loadedmeshes
but BABYLON.CSG.FromMesh() method need a Mesh type as you can see in the documentation here: https://doc.babylonjs.com/api/classes/babylon.csg#frommesh

 

Could someone help me?

Thnak you

[JohnK]

Hi @Aidoru and welcome to the forum from me. Difficult to tell what you problem is without seeing other parts of your code. Here is a rough and ready playground that shows assetManager and CSG working together https://www.babylonjs-playground.com/#SAFTNA

Have a play around with it so that the code looks more like the one you are writing and get back to us.

[Aidoru]

Thank you JohnK.

Here's my code using your (only changed the model) :

var canvas = document.getElementById("renderCanvas"); // Get the canvas element 

var engine = new BABYLON.Engine(canvas, true); // Generate the BABYLON 3D engine

var modelMesh;

/******* Add the create scene function ******/
var createScene = function () {
    var scene = new BABYLON.Scene(engine);

    //Adding a light
    var light = new BABYLON.PointLight("Omni", new BABYLON.Vector3(20, 20, 100), scene);
    var light0 = new BABYLON.HemisphericLight("Hemi0", new BABYLON.Vector3(0, 1, 0), scene);
    //Adding an Arc Rotate Camera
    var camera = new BABYLON.ArcRotateCamera("Camera", 0, 1.2, 40, BABYLON.Vector3.Zero(), scene);
    camera.attachControl(canvas, false);
    var ground = BABYLON.Mesh.CreateGround("ground1", 26, 26, 2, scene);
    ground.visibility = 0.4;
    var assetsManager = new BABYLON.AssetsManager(scene);

	var meshTask = assetsManager.addMeshTask("parte", "model1", "public/Models/", "parte.stl");
	box = BABYLON.MeshBuilder.CreateBox("", {size: 5}, scene);
    box.position.x = 1;
    box.position.z = -2;
	meshTask.onSuccess = function (task) {      
	    task.loadedMeshes[0].position = BABYLON.Vector3.Zero();
        task.loadedMeshes[0].scaling.copyFromFloats(0.03,0.03,0.03);
        fishMesh = task.loadedMeshes[0];
        fishMesh.rotationQuaternion = new BABYLON.Quaternion();
        fishMesh.position.y -= 1.2;
        
	}	

	assetsManager.onFinish = function (tasks) {
        csgFish = BABYLON.CSG.FromMesh(fishMesh);
        csgBox = BABYLON.CSG.FromMesh(box);
        csgHalfFish = csgFish.subtract(csgBox);
        fishMesh.dispose();
        box.dispose();
        csgHalfFish.toMesh("fishMesh");

	};
	
	assetsManager.load();


    return scene;
}

/******* End of the create scene function ******/

var scene = createScene(); //Call the createScene function

engine.runRenderLoop(function () { // Register a render loop to repeatedly render the scene
    scene.render();
});


window.addEventListener("resize", function () { // Watch for browser/canvas resize events
    engine.resize();
});

And here's the error code on Console in Chrome:

TypeError: Cannot read property '0' of null
    at Function.r.FromMesh (babylon.js:43)
    at i.assetsManager.onFinish (myscript_Forum.js:35)
    at i._decreaseWaitingTasksCount (babylon.js:50)
    at i (babylon.js:50)
    at i.e.onDoneCallback (babylon.js:50)
    at babylon.js:49
    at babylon.js:50
    at p (babylon.js:35)
    at babylon.js:35
    at m (babylon.js:35)

[JohnK]

8 minutes ago, Aidoru said:

Here's my code using your (only changed the model) :

In that case have you checked that the box and your model intersect. Actually the first step is to check your model loads. Do you get the same error messages if you only load the file?

See you are using an STL model, have you read this https://doc.babylonjs.com/how_to/stl

If you have read and done this I cannot help as I do not work very much with loaded files. Could also be an error in your file.

[Aidoru]

Thank you John,

Yes I know SceneLoader but I would like to use AssetsManager if it is possible.

Box and my model intersect, and I get that error when using CSG.FromMesh

So I think that probably because FromMesh method need a Mesh amd I only have an AbstractMesh that I think is a Mesh parent if I look on that tree http://doc.babylonjs.com/api/classes/babylon.mesh

[JohnK]

My suggestion to get more help  would be edit your first post and change your title to better reflect your issue. Something like imported stl file not converting to CSG

[wuifi]

Hi @Aidoru

Did you ever solve this problem? I am new to BabylonJS and facing the exact same issue. Neither AssetManager nor SceneLoader (https://www.babylonjs-playground.com/#XA6F3#10) is working for me.

Thanks!

[MarianG]

Hi @wuifi

If you didn't do it yet, please post your question here

https://forum.babylonjs.com