Navigation Controls¶

Basics¶

There are a few built-in functions that adjust the viewer camera to focus on particular angles or items, such as alignToView, zoomToFit, zoomToSelection, zoomToObject, etc. These functions are also available on the default user interface.

Camera Viewpoint¶

Tweaking camera parameters can be a complicated task. bimU.io adopts the prevailling BCF (BIM Collaboration Format) open standard and simplifies its data schema to streamline this process. To capture current camera viewpoint in the viewer, calling the getViewpoint function returns the following JSON format. You can keep it somewhere (e.g., in your own database) and pass it into the setViewpoint function later on to restore a previously saved viewpoint. Note that element information is not stored in the JSON object at the moment.

{
  "camera": {
    "cameraViewPoint": {
      "x": -0.9173076695143414,
      "y": -2.981698504183087,
      "z": 23.5427893532144
    },
    "cameraDirection": {
      "x": 0.23320190941814167,
      "y": 0.48592126302799127,
      "z": -0.8423166836653626
    },
    "cameraUpVector": {
      "x": 0.3644454140253172,
      "y": 0.7593924780881949,
      "z": 0.538982935183467
    },
    "viewToWorldScale": 0,
    "fieldOfView": 60
  },
  "originatingSystem": "bimU.io Web Viewer"
}

Sectioning¶

Section plane/clipping plane information can be captured in the BCF-compatible JSON format as well. Below is a sample camera viewpoint when section box is enabled in the viewer.

{
  "camera": {...},
  "clippingPlanes": [
    {
      "normal": {"x": -1, "y": 0, "z": 0},
      "constant": -15.612010478973389
    },
    {
      "normal": {"x": 1, "y": 0, "z": 0},
      "constant": -27.28821611404419
    },
    {
      "normal": {"x": 0, "y": -1, "z": 0},
      "constant": -3.803048580420051
    },
    {
      "normal": {"x": 0, "y": 1, "z": 0},
      "constant": -9.255849331152472
    },
    {
      "normal": {"x": 0, "y": 0, "z": -1},
      "constant": -6.7235229899076785
    },
    {
      "normal": {"x": 0, "y": 0, "z": 1},
      "constant": -17.06601223246139
    }
  ]
}

It's worth to know that section box visibility and section planes applied in the JSON object are separate things. Section box is a built-in functionality in the user interface. Call the toggleSectionbox function to make it visible or hidden. To control the extents of section box, you can take advantage of the setSectionBox and the sectionAroundSelection functions. Call the resetVisibility function to clear current section box state.

Camera Projection¶

bimU.io Viewer uses perspective camera by default which is the most common projection mode for rendering a 3D scene. If you wish to switch to orthographic projection, call the setProjectionMode function and use the isPerspectiveMode function to check current projection mode.

If current viewpoint is rendered by perspective camera, the fieldOfView property in the BCF-compatible JSON object is a positive value. Otherwise, the viewToWorldScale will be a positive value when orthographic camera is used.