Ultima Game Developer: Full Day-and-Night Cycles
The Cosmos
The night sky has important meaning within the Ultima series. Not only does the world feature two moons, Trammel and Felucca, but these moons are linked to the moongates. Moongate travel is a vital part of the travelling ability for adventurers in Britannia, so obviously the moons are important as well.
In Ultima’s history, however, the night sky was strangely absent from the games at large. The cycles of the moons was present, as was the light and dark periods of the day, in nearly all of the Ultima games. Only a few times was anything beyond this seen.
- In Ultima V, you could peer through a telescope or spyglass and see the eight planets, along with a few of the stars. When a town was being menaced by the Shadowlords, comets would appear near one of those planets.
- At the beginning of Ultima VI, the sky above Ter Mur was shown in a cutscene.
- In the manuals, a single image of the night sky was shown, in connection with the Cosmos.
- In Ultima IX, the sky was present and could be explored at will. According to some sources, this was created from a digital image of the sky over Austin. Additionally, the Journal mentions a constellation, the Hammer of Tulur, and the Ankh is shown when the Avatar ascends.
So, is it important to create a day/night cycle in your Ultima game? Yes, however you need not show the sky and moons at large, unless your game allows the players to gaze upon them. In their stead, simply display some other visual means for determining the phases of the moons, and the time of day. A standard isometric view, such as Ultima games have traditionally employed, leave the sky to the imagination of the player.
In a 3D engine, especially in a 1st person or depth of field 3rd person view, the entire sky may be required. A sky chart, sometimes called a Skybox or Skydome, can be created to display the sky, often with multiple overlapping ones (combined with lighting effects) to transition between the clear blue sky of the day and the starscape of night.
Even if you do not display all of the sky, it may be important to display a portion of it, such as through a spyglass, telescope or a cutscene. These limited glimpses can be much easier to control.
How much of the sky do you want to see?
In the game I’m working on, we are using a switchable camera. This will allow you to use a traditional isometric view, swap to 1st person mode (such as in dungeons), or use a “follow cam”, in addition to the conversation camera.
Since you can see the full sky in either of the latter modes, I’m opting for a full sky. I’m in the process of creating a skydome, partially based on Ultima IX, but with the planets from the Ultima V spyglass and my own interpretation of the constellations. This will be combined with the moon assets I’ve uploaded and a movable light to form a full day/night cycle.
For the telescope, I’m thinking of using a separate skydome. This one will have the constellation images behind the stars, and the virtue symbols behind the planets, to help pick them out. I’m hoping to make something “classic” like: http://www.flickr.com/photos/flyingsinger/156122603/
Information about how to create a day-night cycle and add moon phases in UDK can be found in these tutorials:
http://forums.epicgames.com/showthread.php?t=744541
http://forums.epicgames.com/showthread.php?p=28627079
So, question for you guys. There are two ways to do a full sky that features changes during the seasons. I can either do a full spherical skydome which rotates around whatever northern point I plan to use, which will bring the different constellations into view at different points during the year, or I can have a semisphere that extends just beyond the horizon, and only offsets by a small bit, like a percent per month. Which would you prefer?
The latter way comes with the benefit that I only need to place the planets and stars in a single skychart, while the former gives us more constellations and such to work with, but the planets may not all be visible at all times. I’m leaning toward the latter, for ease of implementation and use, but I’d like some feedback. Thanks!
I would definitely go with the latter. Even in UIX, the sky is just a backdrop in the view field and/or a brief pleasant thing to marvel at. Then the player moves on with the quest. This is rather common across games for me and almost certainly players.