Look around your computer. Pick up something - your mouse, the coffee mug, that box-set of Desperate Housewives DVDs that you, er, are keeping for a friend. Look at it. Turn it around. Throw it up in one hand and catch it in the other. Now, put it down.
Congratulations. You've just accomplished something that Mario, Lara Croft or the Master Chief never could.
You'll have noticed that your fingers did not partially pass through the object when you picked it up, that when you caught it, it did not automatically glue to your hand - in other words, it behaved like you expected it to.
Wouldn't it be nice if gaming worked the same way?
We are instinctively aware of the physics of the world we inhabit. If something doesn't interact properly - from something as ridiculous as an enemy's gun poking through a wall to clothes that are static when they should flutter - it jars, shattering the illusion of immersion. That's where Havok comes in.
"Suspension of disbelief is the key thing," says David O'Meara, the CEO of physics engine creator Havok. "That's what immersion is about, isn't it?"
Dublin, Ireland-based Havok is a world leader in physics middleware - the tools that let developers create worlds where their imaginations can run wild. You can see their work in Half-Life 2's gravity gun, or in a battle in Oblivion. In a world based on rules, Havok is the rule maker - and having just launched the latest version of their software development kit, Havok 4.0, they are becoming an integral part of the immersion process.
Instead of having to code real-world physics from scratch for every game, Havok gives developers a much-needed shortcut, allowing them to concentrate on making fun games.
"Havok physics is a foundation," says O'Meara. "Developers see us as a core component of the game now. No matter how beautiful your animation or whatever is, if the objects are all stuck to the ground, you won't get immersion."
Havok is an unlikely world leader. Although modern Ireland is a hi-tech hub, with companies like Microsoft, Dell and Intel basing their European operations out of the increasingly wealthy and metropolitan country, Ireland's image is still one of rolling green fields and quiet country pubs.
So, in an industry dominated by multi-million dollar giants, how did a small university project turn into the engine that powers worlds? "I think it really comes down to a question of vision and then not letting the vision blind you," says O'Meara.
Havok was founded in 1998 as a result of computer science research undertaken in Trinity College Dublin by Hugh Reynolds and Stephen Collins. What would become Havok was "a really exceptional bunch of guys working together, who had the vision to see that videogames would eventually develop a need for real-time physics - that more interactive and realistic experiences would be the next thing that the industry was looking for."
Developers have flocked to Havok since its 1.0 release in 2000, with Halo 2, Perfect Dark Zero and Age of Empires III among the titles making use of Havok physics - as well as movies like The Matrix Reloaded. From their office in Dublin's Digital Hub, Havok has expanded to such locations as San Francisco, Calcutta and, most recently, Tokyo.