The good thing about great games is that they never go out of style, but for several weeks it seems that the interest in Metal Gear Rising is growing more and more. It seems the perfect excuse to talk about one of the great achievements of Platinum with this game: making us believe that we were really cutting things.
Although it was not the first game to introduce the idea of cuts on apparently solid surfaces – games like Crysis or Afro Samurai had already done so before – it did take the idea to a new level by allowing different angles and sections in the same object. That’s how they got it.
The reality behind an object in a video game
The first thing that comes to mind when you see the main mechanics of Metal Gear RisingBeing able to cut into a thousand pieces almost any object that you come across in the game, is that it goes against everything you think you know about objects in video games.
Usually when you create an object what you do is shape a solid, complete and transparent piece. In other words, there are not dozens of pieces that you can mold to your liking because the cost of creating a brick-by-brick house would be immense, especially at that time.
This is precisely why the house as a whole is an object with an external texture in which, moreover, if you go through one of its walls and the game has not prepared for it, from inside you can see what is behind it.
It is a giant and transparent object whose collisions and textures they are only outside. That’s why in some games you can cheat to sneak under the ground, see where the enemies are and shoot them without them knowing where the shots are coming from.
And precisely with that idea you arrive at Metal Gear Rising, finding yourself with a game in which you can not only cut that house, shaping small bricks thanks to your sword, but you can also see what is inside it, as if each of those cuts had its own internal textures. Witchcraft.
How Cuts Work on Metal Gear Rising Items
When Metal Gear Rising came to market, engines like Unreal Engine and Unity had already toyed with the concept of modifying objects under the term Dynamic Boolean Objects.
The idea behind the term is power”modify the mass” of an object through another object. For example, inserting a transparent sphere inside a cube to give the impression that the latter is perforated.
The magic of physics and mathematics allowed that by shooting at the trees of crisis the object was separated in two -although in reality it was still one with its own physics for each section-, and to avoid seeing the transparent interior of the object, an additional object was added in the cut that simulated the splinters generated after separation.
In the case of Metal Gear Rising the concept is even easier because the cut is always flat, but the magic is even more spectacular because the cuts are seemingly infinite, objects are created at breakneck speed, and each section seems to have a different interior.
But the magic, as always, has a trick. The truth is that there is actually a limit of objects generated based on cuts, which at a certain point causes them to start fading to save memory.
Also, the speed of the cuts it’s calculated to the millisecond in a mix where the animation is fast enough to feel snappy, but also slow enough to give that new object time to spawn. To talk about the interior, on the other hand, an additional section would do us good.
How Metal Gear Rising Made Every Cut Different
We know how objects are cut and how to prevent the trick from being seen by covering the gap with a new object or texture, but how does the game know what object are you cutting to show you one part or another? The key is in the three questions that the game asks each time you are making a cut:
- What object are you cutting?
- What part of the object are you cutting?
- What angle are you choosing to make the cut?
The objects, especially the enemies, are separated into different sections in which each part will show two types of texture depending on whether the cut is horizontal or vertical. The best way to understand it is with the image you have on these lines.
They not only considered what each object was like on the outside, but also how each part of it would look if you cut it in different directions to show an interior as close as possible to the entrails of each one of them.
With all that solved, we simply had to add an animation to each cut to generate the separation between pieces and, voilawe already have the feeling of being making cuts as if they were real.
It didn’t fit them perfectly because not all the objects available had a specific cut – a sofa with a wooden interior, for example – and others were hollow creating a feeling of weird physics, but beyond those little details, I think we’ll all agree that what they created was simply spectacular. It’s normal to keep talking about Metal Gear Rising.