3DVIA® - 3DVIA

In my previous blog post we talked about how games need to render everything in the scene at 30 frames per second. To accomplish that you have to make models with as few polygons as possible but make them look just like they were immensely high poly. How is that possible?

Baking Textures

One way to do it is to fake it, by “baking” the high poly information into a texture and then using that texture on the material of the model. Baking is the process by which render information is transferred to an image file like a jpeg or targa format. To achieve the quality of models you see today in games like Gears of War, Crysis, and Unreal Tournament III each character model has a high polygon and a low polygon version. The high polygon version is used to bake all the detailed information into images, used in the textures of the low polygon version or game model. A combination of renders, including: Normal, Occlusion, Specularity, Diffuse, Bump, Displacement, Glow, and Reflection maps are created from renderings of the high poly model. When used on the game model, they reproducing all that super detail at a fraction of the processing cost to the game engine.

This is done for every object, from a massive space monster to the toilet in the dungeon. The end result is one really beautiful game, with really simple, low poly models, pretending to be super high detailed models. Many of the house models on 3DVIA follow this example, texture over geometry.

Level Of Detail Models

One other way to achieve a smooth 30 frames per second is to use Level Of Detail Models. Have you ever seen objects in a game that look fuzzy from far away but as you get closer they look better and better. This is done by swapping models at certain distances. For example, you have a dwarf that is 2000 polygons, up close and up to 5 ft away he looks great! 10ft away he’s now 1000 polygons and he’s looking ok. 20ft away and he looks like a bop up inflatable punching bag at 500 or less polygons. The texture sizes also decrease per model so that the furthest away the model is, the less resources it uses to be displayed. This is used most often in Massively Multiplayer Online Games. In order to give the player a rich experience they give the area around him all the attention, and anything further away from the player gets less resources.

I’ve had to make a few LOD models in the past and its painful to take a beautiful 2500 model down to a 100 or less LOD model. But in game you really don’t get to see the 500 polygon model as its always the size of a peanut on screen, and as you get closer to inspect the bop up doll, it magically turns into this awesome crazy dwarf!!

-Juan