Real time engine explained

If you want to see your computer model in a virtual environment, you have to use a real time engine. The real time engine allows you to move fluidly through the computer model and look in any direction. Most engines allow you to fly or walk through computer models or “environments.”

Real Time Engines are often referred to as “first person shooters.” The engines primarily come from gaming technology. Sometimes the friendlier term, “first person perspective” is used. Whatever you call these virtual reality programs, they are very powerful design and presentation tools.

The engine or program that allows you to see and move through computer models in a virtual environment were used in games like Doom, Quake, and Unreal. These computer programs are called graphical engines, because they drive video cards and their CPU’s to extremes. Without powerful hardware, these engines can tend to fail. Powerful video cards, CPU(S), and as much ram as you can cram into a machine is recommended if you want to move around large models.
The common drawback is even with powerful computers many engines will fail, when trying to work with computer models from BIM programs like Revit. The problem that most engines run into is they cannot handle the large number of polygons in a computer model.

A polygon is the term used for the surfaces that make up a computer model. A simple box is six polygons.
BIM is created by using solid models which increases the number of polygons. It also usually has a lot of intelligent attributes associated with each object in the model. Unfortunately, these attributes are often useless baggage that slow down real time engines.

The solution is to explode the solid intelligent models into simple surface models. Understanding the difference between solid models and surface models will be helpful in recognizing why BIMs can fail in real time engines.
If your computer model is a simple box, it has six sides. In a solid model, all six sides must exist. In a surface model, you can delete sides that may never be seen. For example, the bottom may be deleted in a surface model, and a box may still appear to be sitting on the floor. The difference is now the computer is only calculating for 5 sides. This isn’t much for 1 box, but when multiplied by the thousands of windows , doors, and walls in an environment that are all essentially modeled with boxes, it adds up. Deleting all the unseen surfaces greatly reduces the work the computer has to calculate.

Another important technique is to use 3ds Max to render to texture. This technique is commonly referred to as texture baking. Texture baking combines the original texture, lighting, shadows, and other effects into a new texture. The new “baked” texture allows you to simplify lighting and to use a much simpler render engine to achieve a similar look.
Rendering to texture can be complicated. It is best if there is as few objects in the scene as possible.
It is easier to hire a game modeler instead of an architectural intern to make a game engine work. However, many employees from the game industry are quickly bored by architecture. They burn out in the typical architectural firm environment.