Monday 21 January 2013

Recent Updates #4

Here is some of the features I have been working on over the past week.

Asteroid Colour Variations

Added some slight colour variations to asteroids of the same rarity (common, precious etc.) so that they are now different shades of the original colour. I think this makes them look a bit more varied and realistic. It doesnt look that different from the screenshots below, but its a lot more noticeable actually in-game.

(With colour variation)

 (What asteroids looked like before)

Also created an extra asteroid set to add some more variation, so that you wont notice asteroid graphics being repeated as often.

Sector and Galaxy Colours

Fine tuned the sector and galaxy background colours as some of them seemed either too bright or dull. I also re-written most of the code and the data file format so that its simpler to modify them or add extra colours through modding.

Railgun and Salvaging Modules

Started to create the visual effects for railguns and salvaging modules. I had to re-write most of the engine/missile trail code so that it could be used for other more general purpose effects. The railgun projectiles will leave a faint trail behind them. It's not quite finished yet so theres no screenshot of the railgun effects.

With salvaging modules fitted, a ship will be able to reclaim resources from the wreckage left over from battle. Once the salvaging module has finished working on a part of wreckage, the reclaimed resources get put into the ships cargo and they can then unload them at a colony. The player controlled ship also needs to be able to do this, so wreckage objects have to become targetable (with the mouse) for the salvaging modules to work.

This could become a problem as I dont want wreckage to become in the way when you are trying to select an enemy ship that is behind it. Smaller objects are always rendered in front of larger ones.

I will be working further on wreckage salvaging this week.

Rendering Optimisation

Spent a bit of time profiling and optimising the object rendering code (ships, asteroids, wreckage) now that I have finished making changes to them and made some small improvements to the overall framerate.

All the objects are rendered using the Painters Algorithm which is rather inefficient. This makes it incredibly difficult to batch objects and render them all in one go. There is a lot of texture swapping and individual draw calls for each object.

Earlier in the development of the game I experimented rendering objects using the z-buffer. It didnt work very well and introduced artifacts and sharp edges around the depth mask for each object. All objects require transparency sorting, so have to use the painters algorithm for rendering.

Although the rendering technique is rather inefficient it still runs very fast, even on the older graphics cards I tested on.

For example, I ran the stress test on an older laptop which has an Intel Celeron T3500 (2.1 ghz, 2 cores) with a Geforce 8200m (not great for gaming) and the framerate was stable between 40 and 70 FPS, depending on how zoomed out the camera is. Not so good when v-sync was turned on, as it then went down to 30.

The stress test scenario has 50 sectors with 100 ships fighting at the same time in each of them (5,000 total) Ship movement, AI and combat is simulated in full detail even when you are not in the same sector to see it.

Compared with my development computer which is 4 years old now (AMD Phenom X4 9950, Geforce GTX 260) it runs the same stress test between 110 and 220 FPS. Thats with v-sync disabled and max settings.

Older single core CPU's likely wont run Galaxial very well. Especially the games with larger galaxies that have many thousands of ships. The game is heavily multi-threaded and benefits greatly from a (fast) 2 core or 4 core processor.

Sunday 13 January 2013

Recent Updates #3

Quick update with a few things I've been working on recently.

The past few weeks have mainly been spent cleaning up and re-writing large chunks of code including the ship AI and transitioning everything over to the new window interface system.

Colour Banding

I added some dithering/gaussian noise to hide the colour banding thats noticeable on some gradients in the game. The sector backgrounds and galaxy map screen were particulary affected by this. I was quite reluctant to do this as when you zoom in you can clearly see the noise, which really doesnt go with the 'smooth gradient' visual style of the game.

I will perhaps make the dithering/noise optional so you can turn it off if you want. (for 30-bit colour monitor users!)

Interface Windows

I have been improving the layout and design for many interface windows, it involves lots of trial and error to get everything pixel perfect. The screenshot below shows the new ship orders window.

(Click for fullsize)

Ships with a transport order can now (optionally) load cargo at the second waypoint if you dont want them to return empty.


I am also looking to license a unique soundtrack of over 4 hours of atmospheric/spacey electronic ambient music for the game. Theres still a few more details to finalise so cant provide any samples here yet.

The next few weeks I'm going to start working on some of the more gameplay related stuff as I'm rather sick of user interface programming at the moment. It's so time consuming.