Sunday 6 July 2014

Simplifying scripting

Using scripting languages in game development has been common for years. And for good reason - most of them are easy to learn, and the lack of compilation decreases iteration time. Right now pretty much every major game engine has a scripting layer. Zaria too. It uses slightly modified JavaScript running on top of Rhino.

During my previous game projects I also used a variety of scripting languages: UnrealScript, NWScript, Lua etc. While working with them I found one thing really annoying - in most cases without browsing through a wiki or looking through documentation I had no idea what the available API was. Going through various web pages, or even printed documentation made it difficult to get back into coding. It's easy to loose focus and more difficult to get it back again.

With compiled languages it's easier. Their strict structure makes it simpler to implement various code completion and suggestion tools, which in turn makes exploring the available APIs quicker.

What Aurora (and Electron) toolset had, was a searchable, drag'n'drop list of all available script functions right next to the editing area - extremely useful stuff. I really missed such a feature when working with Unreal Engine 3 on Blade Lords.

In order to not repeat past mistakes and learn from good examples I decided to implement a similar feature in the Zone Editor.

A searchable palette on the right lets the user drag any available function right into the script. Functions are grouped by category, which can be defined by whoever creates the script function. Tooltips also provide some basic information on what the function does. Also to make it even more easy, other scripts can be dragged from the file view into the editing area, which will result in a properly resolved import.

On the code side adding a new script function is really easy. Just create public static method and add the @ScriptFunction annotation. The editor will parse this data and show the function in the palette.

There are other features I can imagine that could further enhance script writing, but for now I think this already makes stuff much clearer and simpler.

Thursday 3 July 2014

Adding lights to entities

I implemented static lightmap support some time ago with nice results. However moving stuff did not yet have a lighting solution.

I wanted to have something in which the data for lighting would be common for static and dynamic objects. What I what I came up with is to save the light data (position, color, power, radius) that is used to generate lightmaps and use it also to create localized lights for entities.

By localized I mean that each entity creates its own set of lights, which affect only it. This allows for attaching quite a lot of them, as the lights will affect only a small amount of geometry and gives a lot opportunity for LOD optimizations. The only down-side is that this method will not support shadow casting. However, in the end, this is not that big of a drawback, as such an amount of dynamic shadows would kill the framerate anyway.

I created a component for that, so making an entity dynamically lit, is now trivial. The first test can be seen here:

The map from which this video was taken:

The scene had 8 lights and with 7 entities the fps was around 2700. So far not bad.