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autodesk-forgeautodesk-viewer

Generating 2d views from cut planes automatically

i'm new to the autodesk viewer and the others api and I could use some help figuring out what tools are the best to do what I want.

I'm using the autodesk viewer to let users generate 2d views of cut planes, in order to do this I simply use the getScreenshot function from the viewer and save it as a Blueprint in my app.

What I would like to do now is that when the user updates his 3d model, to automatically update my 2d views with the new 3d model.

Currently the only solution I came up with is to store the position of the camera when taking the screenshot and then when the 3d model is updated, have another computer in the background go in the viewer and take the screenshots again at the same location.

This does not seems to be a very elegant solution so I would like to know if there's an alternative, like a way to generate 2d views from an api call or maybe use the Design Automation API with the viewer to take the screenshots ?

Another thing i'm struggling with is getting precise measure of the 2ds views i'm generating, my current solution is to calculate the distance between the camera and the cut plane and then use the fov to get an approximate measure, the formula looks like this :

Math.tan((viewer.getCamera().fov / 2) * Math.PI / 180) * distanceBetweenCameraAndPlaneCut * 4;

but it is very dependent on the user facing the plane cut at a 90° angle and i'm thinking there should be something better to do with the measure tool.

Thanks a lot for your time!

Solution

    1. You should be able to run the Viewer on a server using puppeteer (without client-side components) to generate screenshots: https://forge.autodesk.com/blog/running-forge-viewer-headless-chrome-puppeteer
      Note: you could also use Design Automation API in order to do something similar, but then you are limited to the file formats the given product (e.g. AutoCAD) supports as input

    2. You could also simply save the state of the Viewer and reset it next time you load the same model in order to take a screenshot of the exact same area using getState()/restoreState(): https://adndevblog.typepad.com/cloud_and_mobile/2015/02/managing-viewer-states-from-the-api.html

    3. Why are you trying to measure the distance between cut plane and camera position? Is that in order to restore the Viewer state/camera? If so, then the solution mentioned in 2. should help