How Separation & Convergence Interact
Now that we know how things look visually, the next step is to understand how to adjust the settings to your personal taste. In the previous section, we learned that “separation” determines the intensity of the 3D depth sensation, and “convergence” determines at what point the scene transitions from a depth experience to a pop-out experience.
We can simplify these terms even more. Think of separation as your depth budget, and convergence determines how much of that depth is spent on going inside the screen, and how much is spent going outside the screen.
The easiest way to adjust your stereoscopic 3D experience is without the help of 3D glasses. What you see determines how the 3D experience is going to look.
Here are three short video clips of how you can expect a modern game to appear with a stereoscopic 3D software solution. We are using Bethesda Softworks’ Oblivion as an example. The instructions presented here are generic, and we will have a more detailed setup guide for different software solutions at a later time.
Let’s begin with the premise that we have reserved enough separation or a “depth budget” to do as we please. The remaining variable is “convergence” or the location of the “Zero Parallax” or “Neutral Point” line.
Depth Only Settings
Let’s start with a zero convergence and put our neutral point where our monitor glass is located.
Look at the monolith in the center of the screen and the surrounding environment. Notice how everything is doubled at first, and as you walk toward the monolith, its separation gets closer and closer until it is completely joined. The point where the objects are joined is your “zero parallax” or “Neutral Point”. This is a depth only scenario where you will be able to see the distance into the screen, but nothing will ever penetrate the glass of your monitor.
Pop-Out Only Settings
Using our stereoscopic 3D driver software, we can move our convergence point very far into the screen. Let’s move it as far back as the mountains!
If you look at the video, the entire screen is a single image. However, as you walk towards the monolith, it starts to separate – not the other way around like with depth. The “convergence” or “Neutral Point” is no longer where your monitor’s glass is; it is deep inside the screen. This is how a pop-out only experience is organized, and as you walk closer to objects, they will breach your monitor’s glass, but the objects behind them will seem flat.
Depth and Pop-Out Mixed Settings
Instead of putting the convergence point very far in the distance, we are going to put it somewhere between our monitor’s glass and the mountains.
Look at the far back of the image with the hills and trees – everything has separation to it. Now look at the monolith again. As you walk towards it, it starts separated, completely joins together into a single image, and then begins to separate again. The point that the images completely join together is your new “convergence” or “Neutral Point”. In this case, the convergence point has been put behind the monitor’s glass, but close enough that you see both the depth and pop-out sides of the visual divide.