Mediocre game technology

One of our early goals with Smash Hit was to combine audiovisual realism with highly abstract landscapes and environments. A lot of effort was put into making realistic shadows and visuals, and our sound designer spent long hours finding the perfect glass breaking sound. However, without proper acoustics to back up the different environments, the sense of presence simply would be there.

To achieve full control over the audio processing and add environmental effects I needed to do all the mixing myself. Platform dependent solutions like OpenAL and OpenSL cannot be trusted here, because support for environmental effects is device/firmware specific and missing in most mobile implementations. Even it was available it would be virtually impossible to reliably map parameters between OpenSL and OpenAL. As in most cases with multi-platform game development, DIY is the way to go.

Showcasing a few different acoustic environments Software mixer Writing a software mixer is quite rewarding – a sma…

Smash Hit is a game built entirely around destruction. We knew from the beginning that destruction had to be fully procedural and also 100% reliable. Prefabricated pieces broken the same way every time simply wouldn't be enough for the type of game we wanted to make. The clean art style and consistent materials made breakage easier, since everything that breaks is made out of the same, solid glass material. Procedural breakage Physically based breakage is hard. Really hard. I remember NovodeX had some kind of FEM approximation for breakage in the early days of PhysX, but it never worked well and didn't look very convincing. I think for most game scenarios it is also completely overkill, especially for brittle fracture, like glass. I designed the breakage in Smash Hit around one rough simplification – objects always break where they get hit. This is not true in the real world, where tension builds up in the material, and objects tend to break at their weakest spot, but hey, we&…

Our latest game Smash Hit has gone far beyond all expectations, being the #1 free game in over 100 countries during launch week and approaching 35 million downloads! I will write several blog posts about the technology here, starting with a tech summary of what is being used and then go deeper into each subject in future posts.



Physics
This is by far our most physics intense game to date. It's almost like a physics playground with a game glued on top. The physics engine is tailor made for this game specifically, but builds on top of the low level physics library I was working on a few years ago. The game is actually a great show case for the low level physics library since it is very non-generic. It's a streaming, highly dynamic world where more or less everything is moving all the time and objects get inserted and removed constantly. Therefore there is no deactivation (sleeping) or islands generation. There are also two types of objects simulated differently. The full rigid b…

I will give a talk on fluid simulation on GDC this year! Make sure to attend the physics tutorial.

The session will focus on the formulation of a fluid constraint. In contrast to most other particle-based fluid simulatiors, mine uses a sequential impulse solver, normally found in rigid body engines. This improves incompressibility and makes interaction with rigid bodies very stable. This is the method used in Sprinkle and all 3D fluid movies posted earlier on the blog.

The tutorial does also include interesting talks about convex hull creation, physics debugging, constraint solvers and character collision.