Monday, July 27, 2015

Unreal Engine DevLog #19: Line of Sight based Visibility

Hi, it's been quite a while since the last dev log on Project Horizon (yes, got changed to a less generic name). I had been working on my FPS Tower Defense Toolkit and some other experimental stuff for a few months. The toolkit has been submitted to Epic Games for Marketplace review and we're done with all the agreements. There has been some delay as I had to convert my project to v4.8 midway and there had been an engine bug that I had to find a workaround for. With the new code submitted, I'm awaiting their response regarding further details. 

Meanwhile there had also been some major updates to Knut's Advanced Turn Based Tile Toolkit, which makes it much more optimized and well structured than before. So rather than integrate all those changes into my project, it was much easier to transfer my code into his updated toolkit. And that took a while to implement and finally it was time to add some exciting new features to the project. First in line, was Line of Sight based visibility. An earlier unannounced version of this was already working partially in my old project. So I ended up using that, did some optimizations and finally we have something that works pretty fine. It's using a mix of grid based calculations and collision meshes to achieve this. The grid calculations are mainly used in places where the LoS will have a direct impact on player actions. For scenarios which are mainly important from an aesthetic viewpoint, I've used a collision mesh to reduce the time calculations. It's quite accurate, but I need to add a small line trace calculation at some point in the future. So here's a video demonstrating the new feature:

That's all for this update. Next time, we're gonna see if we can add the Overwatch ability from XCOM: EU. Until then, goodbye and stay classy.

PS: For anyone interested in Knut's turn based tile toolkit, you can check it out here: