ARFX Virtual Screen

Section 7. ARFX Virtual Screen

The ARFX Camera’s screen represents your physical screen’s dimensions and location in virtual space. By default, the tiny rectangle floating in front of the camera model is simply set to a size that is reasonably close to the dimensions of a small 1080p display. It is merely a size that can be used and tested on without much effort.

When the screen’s dimensions are 0 x 0, you will see this tiny square floating before the camera.

However, because the dimensions have not been set for your particular display, ARFX’s distortion warp effect will be incorrect, resulting in an image that is stretched or squashed depending on your display’s aspect ratio.

This is an extreme example, but you get the gist. Always make sure to set your dimensions correctly!

Once you’ve set your physical screen’s dimensions on the camera, the representative virtual screen will immediately scale itself appropriately.

This screen is set to 600cm x 350cm both in Unreal and in the real world.

Section 7.1 About Calibration

When calibrating any ARFX Camera, what you are doing is actually determining the position and orientation of the screen in virtual space. The closer and more accurate you are to the screen’s center, the more accurate the resulting tracked image. Once calibrated, the Hero Tracker used on the physical camera will have its position calculated relative to the calibration point. In other words, you can consider your screen’s physical and virtual position to be your stage’s origin point.

More on the topic of calibration will be covered in the Tracking Section.

Section 7.2 Camera Model Misconceptions

To be clear, the ARFX Camera in the Editor’s Viewport is NOT representative of your physical camera’s location. Nor is the preview window a perfect representation of what you will see when in play (although it can help). This must be made clear as there are some who have thought, justifiably, that the camera model in the editor should either be where the screen is offset or that the camera model must be clear of obstacles when it is actually the representative screen itself.

When placing the camera in your scene (or any ARFX Bookmark, for that matter), you will not know how or where the resulting image will look until you run the scene and move your tracked camera into a suitable position.

It is for this reason that it is recommended that you make your bookmarks while in play with a tracked position that will generally be used.

Section 7.3 Use the Floor For Larger Displays!

If your physical display is large enough to reach all the way to the floor, the best practice is to also root the ARFX camera to the virtual floor of your scene. There are two simple ways to do this:

Section 7.4 While In-Play

You use SnapMode to have the camera set itself to what it thinks is the floor. Pressing the T or Left Stick Button will enable Snap Mode, and then tapping Down Arrow or DPad Down will cause the camera to snap to the floor using your screen’s height. Once you have a good position, create a bookmark (0 or DPad Left when not in Snap Mode) at that position to save it for use.

Section 7.5 In Editor

Simply move the camera itself and use the outline of your virtual screen as a reference point. Once you see that the solid line that makes up the screen turns into a dotted one, move it up one step, and it should now be aligned with the floor.

It may be hard to see depending on your display and resolution, but there should be a distinct difference between the screen not clipping into the floor and when it is.

Notice how the screen maintains contact with the floor as the image distorts. The effect in the physical camera’s viewpoint should make the illusion of looking deeper into the scene all the more realistic!

Important

You can do this effect even on walls. Just align the sides of the screen to that of a way to get another interesting virtual shot._

Section 7.6 A Word on What is Being Seen on Screen Versus What the Physical Camera Does

We at ARwall cannot stress this enough. Always compare what you are seeing on screen to what your physical camera does! The distortion warp effect of ARFX may look odd from a 3rd person perspective, but a good experiment to do is to actually hold the camera tracker to your forehead and see how its perspective warp actually works.

A good analogy that we would like to give is that it is like looking through a window the size of your display. For many filmmakers we have partnered with, it is usually seeing this effect firsthand on camera that they understand what is being shown on screen.

For more details on how to make sure the bottom of the screen is on virtual ground please refer to this guide.