Updating a geometry inside a mesh does nothing

问题

I am using THREE.JS rev 49.

My program needs to update a mesh by changing it's geometry. Unfortunately the display does not seem to update.

Here is my code :

// theObject is an array of associatives :

// {
//     object1: {mesh: undefined/THREE.mesh, mat: THREE.Material, geo: THREE.Geometry}
//     object2: {mesh: undefined/THREE.mesh, mat: THREE.Material, geo: THREE.Geometry}
//     ...
// }

// In my function, theObject[i].mesh geometry must change to be theObject[i].geo.


for(i in theObjects) {

    //*
    if ( theObjects[i].mesh == undefined) {
        theObjects[i].mesh = new THREE.Mesh(theObjects[i].geo, theObjects[i].mat);

        theObjects[i].mesh.geometry.dynamic = true;
        theObjects[i].geo.verticesNeedUpdate = true;

        scenePostsurgery.add(theObjects[i].mesh);
    }  else
        theObjects[i].mesh.geometry.vertices = theObjects[i].geo.vertices;

}

Do I have to add something else ?

/Oragon

回答1:

If I understood correctly you are updating vertices here:

else{
        theObjects[i].mesh.geometry.vertices = theObjects[i].geo.vertices;  
}

Try to change this code to :

else{
         theObjects[i].mesh.geometry.dynamic = true;
         theObjects[i].mesh.geometry.vertices = theObjects[i].geo.vertices;  
         theObjects[i].mesh.geometry.verticesNeedUpdate = true;
    }

In if(){} you create a mesh and in else{} you update so dynamic = true and verticesNeedUpdate = true you need to set to mesh which is in else{}.

回答2:

When changing the entire geometry, I think the easiest way is to remove the old one (scene.remove(geometry), then add the new one (scene.add(geometry)). I think the cost of modifying the mesh and geometry parameters and properties is the same as adding a new one, although adding is much easier and saves a lot of headache!

来源：https://stackoverflow.com/questions/15384078/updating-a-geometry-inside-a-mesh-does-nothing

标签

three.js