Synther Windows, Mac, Linux game

Synther

Introducing Portals/Entrances

1. What are portals and what do they do
Portals are objects, which can be either manually placed, or automatically generated on the game level. They are very useful for managing the state of the game, in regards to whatever either passes through them, sees or stands in them. Usually, they are used for optimization and to stop areas, which are not visible, from rendering. Most often we can find them in the doorways and between distinct parts of the level. Thus they are useful for closed-areas, like cities or interiors, but are not so useful for landscapes.

2. What portals do in our project
In Synther, besides the classic portals usage for rendering optimization, we use them for the following:
1. Ambience. Various locations might have a different ambience theme playing.
2. Music. Same matter as with the ambience.
3. Light effects. The city uses cold colors range, while interiors have hot colors.
4. Audio filters. Sounds will sound different in canals, opera, streets, etc.
5. The quick load of a location placed elsewhere.
6. Trigger an action that’s related to the portal’s area.

3. How do they work
Below you can see in-game how going through the portals looks and feels like.

Notice how the ambience change is instantaneous, while music and lights take some time to adapt to the new area settings. If the player decides to return through the portal during the transition, the same music continues playing. An exception to this is when combat happened. Then at least the first part of the area combat theme will continue playing, even if the player enters other areas. An interesting fact: We’ve got a total of five themes per area. Three of which are combat themes, one is a base music, and one is ambient. Not counting ambient effects of the objects themselves.

Every time a special object touches a portal, in this case, it is the player, we follow it. Then when it leaves the portal, we calculate the difference vector from the portal pivot position to the object pivot. Each portal can be rotated around its vertical axis, so the front can be placed facing north, east, west, south or at any other direction between those. If the difference vector is also facing the same way as the front vector of the portal (Angle between difference vector and portal forward vector on the vertical axis is between -90, 90 degrees), we’re entering side A. Otherwise it’s side B. Here is a visualisation to better see what is happening in our portal when the player passes through it:

We’ve got one more type of portals, which we call load portals. They are used for loading a new location and transporting the player there, in the least interrupting way possible (Yes, here at Neofuturism we hate loading bars too). At first, we wanted to have a whole city loaded at once, as the game was not that demanding for the hardware after all, and what is 4 GB of ram for the current generation of computers. Still, after the introduction of thousands of NPCs living simultaneously in the city, and shrinking space for building expansions, we’ve decided to use some kind of loading solution, and that’s what we’ve got now:

4. Future of portals
Normally portal objects are static, that means that they don’t move anywhere from the place they were originally placed. We’ve found out though, that making them dynamic for some cases allows for more possibilities. For now, only subway cars use dynamic portals, but we’re looking into putting them into other vehicles, too!

For the end a bonus video of a detective versus the subway car:

Synther will be soon available on Steam:
Store.steampowered.com

-Griz, Developer