Tutorial 6: Panorama Calibration

Transcript

To achieve a correct and perfect visualization. We must first calibrate the panorama. However, every panorama is of course a little bit different. So in this tutorial, I'll show you three scenarios you might encounter when calibrating your 360 images.

Let's start with the most straightforward scenario. When you're in the calibration tab, you can do a first check as to what extent the panorama is calibrated by clicking the Cycle Opacity checkbox.

When we look at the road, it's evident that we are to tweak the positioning of this panorama. Let's pause the opacity cycle by unchecking the checkbox. You can also change the opacity using the up and down triangles. With the move tool selected. Use the arrow symbols to line the road up perfectly.

You might want to go back and forth between moving and then adjusting the opacity to ensure a precision.

So the reason why this panorama is relatively easy to calibrate is the obvious visibility of its horizon, and an obvious landmark in the background. When you're in the calibration tab, look for the landmark on the 2D map.

And align your view with the landmark.

Now select the rotate tool and rotate the panorama to it on the x axis.

Next, line up the 3D horizon with the horizon in the panorama by tilting the camera to the front, back or sideways.

Please keep in mind that whenever you create a viewpoint, your image is projecting against a spherical background. This means that when you rotate the image, the image will be rotated on both sides of the axis you are rotating. Whenever one side goes down, the other side will go up and vice versa.

Rotating the image to the left or right means that what lies behind you will also rotate the opposite direction.

Please go back and forth, changing which way your view is facing. To make sure the panorama is as accurately aligned as possible when the panorama has been positioned and rotated, you can conduct a final evaluation of your work by shifting the opacity.

That looks good. This panorama is calibrated and ready to be used for perfect visualizations.

The following panorama is a little bit harder to align. The horizon isn't visible everywhere, and where it is visible, it's not a straight line. Let's cycle the opacity to see what we're working with. Now let's move the panorama to the correct position using the move tool. It may seem like a small adjustment, but it does matter.

Now select the rotate tool, and let's make sure that the horizon line of the 3D world is lined up with the horizon line of the panorama.

If you want, you could type in the values in the boxes or use the arrow icons next to them. However, the rotate gizmo is more convenient as it will rotate or tilt the image according to where your view is pointing.

Again, it's important to increasingly refine the calibration of your panoramas by directing your view to different areas of the image. Also, going back and forth between applying the move tool and the rotate tool will refine your calibration. As we look at our work with the opacity slider checked. We can verify that we've successfully calibrated a hilly terrain.

Finally, let's take a look at the most difficult scenario. In this case, there's some altitude variation in the terrain and there's no visible horizon. This is where OSM and bad buildings will help. Open street maps. Buildings are a type of 3D replica of all buildings around the world. If your project is located inside the Netherlands, you can also enable high detail 3D bag data of all buildings there.

Having either of these data sets enabled will help you calibrate panoramas in the absence of other reference points from the 3D world. To enable OSM buildings, go to settings and scroll down to where you see OSM buildings. These are only compatible with the cesium Iron world terrain, so make sure that this is selected when using this OpenStreetMap data set.

3D bag buildings are only compatible with the air and for terrain data. So if your project is in the Netherlands, select air and for terrain data under World Layers and then under 3D tile sets, select bag 3D buildings. Head on back over to the panorama you want to calibrate and click on the calibration tab. As you can see, the buildings are now visible in the background behind the photo.

As we did in the previous two scenarios, use the move tool to reposition your panorama to line it up with the road underneath it.

And now, with the rotate tool selected, we can start lining up the 3D buildings with the buildings from the Panorama. Zooming in and lining up the corners and bases of the buildings using the rotate tool will result in the best possible outcome.

The more buildings you can identify and align to the best of your ability, the better.

After tweaking back and forth until everything seems to fit, we can cycle the opacity once more.

Despite a limited amount of reference points, this Panorama two is ready to be used for visual communication to stakeholders. Please remember that every panorama is different and that panorama calibration may require practice and tweaking back and forth. You can request calibration assistance if needed. If your placements float or sink after proper calibration, it may also be the case that your local terrain data is not accurate, which can be mitigated with high detail terrain.

We'll delve deeper into terrain data and world layers in tutorial 11.