Setting Perspective Camera before model is loaded

[slinkire]

We have “BIM-mode” on our models, and would like to use “Perspective” as default camera projection on 3D models (like IFC and Revit).

But we are only able to set “Perspective” after the model is loaded.

So first the model is loaded with camera projection “Orthographic” , and then it is visually changed to “Perspective” in the viewer.

We’ve tried setting this
this.viewer.getView(0).setProjectionMode(Communicator.Projection.Perspective);
in different viewer callbacks, but have not been able to make it work as a default setting before the modelStructureReady callback.

Any idea on how to do this as default camera projection before loading the model?

[slinkire]

I’ve looked as the description here to see if it could help:

How-To: Set View Behavior Prior to Model Load

As a developer, I’d like to learn how-to load a model with specific view behaviors already set without seeing a noticeable transition when the model is loading . Introduction User experience can suffer if we first load a model with the default settings, then change those view settings to our desired effect after the model is loaded. As a user, I want to be able to set the view settings (i.e. projection mode, visibility, camera orientation, etc) before I see the model loaded into the scene. Ins…

I thought I fixed it using this approach, but I still get a “jump” between Orthographic and Perspective projection.
It is almost invisible on small models, but quite annoying on larger model.

[tino]

Hello @slinkire,

Perhaps we can leverage the paired functions pauseRendering/resumeRendering to better time the camera projection switch, for example:

viewer.setCallbacks({
      sceneReady: function() {
        viewer.view.setBackgroundColor(Color.white(), Color.white());
		viewer.pauseRendering();
      },
	  modelStructureReady: function() {
		let cam = viewer.view.getCamera();
		cam.setProjection(Communicator.Projection.Perspective);
		viewer.view.setCamera(cam);  
		viewer.resumeRendering();
	  }
    });

So basically, rendering is paused on sceneReady and resumed once the camera projection has been set to perspective in modelStructureReady.

Thanks,
Tino