Incorrect ModelToSheetTransform in forge viewer

Question

I use modelToSheetTransform in viewports data to map position between 3d and sheet view. I have 1 3d view with some sheets with it, but 1 of my sheets have wrong position after map, the other sheets are correct. Did I miss some setting in my sheet or was I setting something wrong?

This is my code to map position:

const aecData = await Autodesk.Viewing.Document.getAecModelData(
    viewer.model.getDocumentNode()
  );
const viewport = aecData.viewports.find(
      (v: any) => v.sheetGuid === sheetGuid
    );
const sheetUnitScale = viewer.model.getUnitScale();
modelToSheetTransformMatrix = Autodesk.AEC.AecModelData.get3DTo2DMatrix(
        viewport,
        sheetUnitScale
      ).clone();
    

Answer 1

Not sure what the Revit model version generating or saving your Revit model is.

Probably, it's related to a known issue. Could you try to omit the modelToSheetTransform before loading 'Autodesk.AEC.LevelsExtension' and 'Autodesk.AEC.ViewportsExtension' to see if it helps?

let aecData = viewer.model.getDocumentNode().getAecModelData();
aecData.viewports = aecData.viewports.map( vp => { vp.modelToSheetTransform = null; return vp } );

//Before loading 'Autodesk.AEC.LevelsExtension' and 'Autodesk.AEC.ViewportsExtension'

Viewer will use another approach to calculate the transform, but please ensure your floor plans and sheets are configured with the rules in this link:

https://stackoverflow.com/a/69941583/7745569

If the above doesn't help, please consider providing a test Revit model reproducing this issue to aps (DOT) help (AT) autodesk (DOT) com for investigations and pointing out which views can reproduce this issue in the email.

ref:

• https://github.com/yiskang/forge-viewer-hypermodeling-revit/blob/main/public/js/SheetsBrowserExt.js#L279
• https://github.com/petrbroz/forge-viewer-samples/blob/master/public/aec-mapping-2d-to-3d.html#L135