CODEWITHSUNDEEP
autodesk-forgeautodesk-viewerforgeautodesk-model-derivative
Brendan Owens
Brendan Owens

Reputation: 33

maxtrixWorld property identical for all room objects when converted to THREE.Mesh

In the Autodesk Forge Viewer, when getting the maxtrixWorld property of an object that is a "Room", I have observed that the property is identical for each Room in the model, regardless of where the object is actually located in the model. This is not the case for any other objects in the model (they all have unique maxtrixWorld properties that correspond to their location in the model).

I have retrieved the maxtrixWorld data via multiple methods based on the fragment IDs that build the room objects, all resulting in the same outcome:

Get a THREE.Mesh object with a maxtrixWorld property

const renderProxy = viewer.impl.getRenderProxy(viewer.model, fragId);

Get a THREE.Mesh object with a maxtrixWorld property

const meshObj = fragList.getVizmesh(fragId);

Get the matrixWorld via fragList helper function getWorldMatrix()

const matrix = new THREE.Matrix4(); fragList.getWorldMatrix(fragId, matrix);

The Rooms do appear in the correct location in the model, which makes me think that they have a transformation baked into their geometry since their matrices are not determining their location in the model.

Is this a limitation of how Rooms are built in Revit or perhaps a result of the model translation process? Is there a way to retrieve the correct matrix information for these objects? The models are being processed via Forge with the generateMasterViews flag set to true, which enables the room data to be generated.

Upvotes: 1

Views: 80

Answers (1)

Petr Broz
Petr Broz

Reputation: 9942

I just tried getting the world transform of a couple of rooms in one of the official Revit samples (rac_advanced_sample_project.rvt), using the following code in the viewer:

function logWorldTransforms(viewer, dbid) {
    let tree = viewer.model.getInstanceTree();
    let frags = viewer.model.getFragmentList();
    let mtx = new THREE.Matrix4();
    tree.enumNodeFragments(dbid, function (fragid) {
        frags.getWorldMatrix(fragid, mtx);
        console.log(mtx.toArray());
    }, true);
}

And you're right - no matter which room I tried, they all had the same matrix (in my case with a constant offset of (-140.60, 0.50, -17.48)). When using the generateMasterViews flag, the Model Derivative service most likely bakes the offsets into each room's geometry. With that said, you can still get the bounding box of each room, and that will give you a better indication of where the room is positioned.

If you believe this is a bug, please report it to forge (dot) help (at) autodesk (dot) com.

Upvotes: 1

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