About the employment of displacement mapping of "Half-Life2"

Zen:
There was an explanation that the geographical feature data of "Half-Life2" engine had the attribute of displacement map data.

BVB:
Yes. Geographical feature upheaves or caves by interference of a player, and displacement mapping(*) technology is used for the expression.

In "Half-Life2", the software-based displacement mapping technology has realized upheaval or cave of the ground, and modification expression of some objects.

ZEN:
Displacement mapping means that the so-called Sub-Division Surface technology which carries out arithmetic division of the polygon is implemented.

BVB:
That's right.

ZEN:
Although the displacement mapping can be accelerated by ATI RADEON 9500 or greater using TRUFROM 2.0, does the game utilize this function?

BVB:
No. The function is processed by the software.

(*) Simply speaking, a technology of sticking unevenness on a polygon at a geometry level. Unlike the bump mapping which performs shade processing, unevenness is geometrically stuck as if the surface was actually irregular.

About physical engine

BVB:
HAVOK offered us the basic set of very powerful physical engine.
A hit judging, a kinetics simulation, a pressure simulation, spring dynamics, and a simulation of actuator etc. is main, I think.
Since each function could not be used separately in a game like "Half-Life2", we rebuild the game physics engine which works well in "Half-Life2" world combining basic physics engine which includes interference of objects and the relation of a reaction.

Although the three leg huge arms swings and strolls heavily owing to the high center of gravity, such action also follows the physical law in the game world.

BVB:
Absolutely. And we also developed "Physics AI" technology newly for "Half-Life2". The technology is incorporated in the vehicle or the machine appears in "Half-Life2", and in our game design tool.

ZEN:
How does the system act on a game concretely?

BVB:
For example, there is a "substance system" in "Half-Life2", and the system enables high level work of game designers or artists.
When we utilize this system, the physical property of a character is calculated automatically and the action comes to follow the physical law in the game world, only by giving a substance parameter to the part which constitutes the character.

ZEN:
That is, if a character is designed with heavy material, he walks heavily even if you don't attach heavy action.... The system is interesting.

About the adaptability to programmable shader

BVB:
When you want to enjoy image expression on the level of an official announcement at SIGGRAPH, DirectX-9 GPU is required.
However, although some expression is simplified, you can enjoy "Half-Life2" by DirectX-8 GPU. Moreover, when you use DirectX-6 or 7 GPU, "Half-Life2" can still be playable, although it will be simplified further more.
Since "Half-Life2" is a PC game, it is programmed with flexibility.

ZEN:
We think of "Half-Life2" as is suitable to DirectX-9 GPU. Then, we can say that "Half-Life2" utilizes the programmable shader 2.0 which is special-feature of DirectX-9?

BVB:
Sure. "Half-Life2" is using both programmable shader 2.0 and 2.0+.

ZEN:
For what expression is the shaders specifically utilized?

BVB:
Though regrettable, I can not answer about it.

Zen:
For example, does "Halfe-Life2" engine perform such things as changing the rendering path or switching moving shader, according to the video cards like GeForce FXs or RADEON 9500 and faster?

BVB:
I can't answer about it, either.

ZEN:
It is often with the case with our readers, they tried to perform 3D benchmark only even if they have DirectX video cards. When we show how DirectX can be used for "Half-Life2"'s expression, it will become useful information for them.

BVB:
Although I am sorry, I can't give shader-related information beyond this up to now. At present, only information I can tell is that, as for "Half-Life2", programmable shader 2.0 or 2.0+ also works really well.
As a matter of fact, authoring to high-end GPU is under advance now.

The water surface is rendered by the dynamic environmental bump mapping, by which the circumference moves with the effect of ripples. By the relation between positions of a light source and a viewpoint, the fresnel effect that changes the transparency under the water surface is also supported. The effect is produced by programmable shader, indeed.

Last Words

BVB:
Loading occurs like "Half-Life". The flaw is not fixed yet.

The hero is, same as the previous game, Gordon Freeman. When I asked "Is the mystery of the previous game solved?" he answered "Secret!"

BVB:
I have not considered "Half-Life2" and "DOOM III" are rival <g>. The purpose of the each games is different and the directivity of the contents is also different. I think what they are doing is wonderful and it is also very excellent what we are doing.

ZEN:
We can roughly say that "Half-Life2" is open field type, and "DOOM III" indoor one.

BVB:
Indeed. Each of us developed the optimal technic for what we are going to do, and thinks that it can be done. Even if we think of one technique of lighting, both differ.

ZEN:
I agree.
While "Half-Life2" puts emphasis on expression of reality, "DOOM III" gives us the atmosphere of Gothic horror movie inside of the reality.

BVB:
I don't think that every game developer is so mutually conscious. When I see a excellent game in the other company, I applaud the game immediately "Great!", "Fantastic!".

Owing to the top-level graphics and contents, "ICO" on PS2 have the completeness. Although Japanese regard the game as average work, in the European and American game developer, "ICO" has the greatest popularity.

BVB:
We have not implemented benchmark mode on the game yet, but are going to add the feature anyway. Talk about porting, Xbox is leading and others are undecided.

ZEN:
The last question; what is your favorite game?

BVB:
Since our work of shipment is the last scene, I hardly play games now <g>. I play "Medal of Honor" or "Battlefield 1942" recently. When I talk to console games, I play "ICO" on PS2. "ICO" entertains me because both graphics and the contents were wonderful.

ZEN:
Thank you for today. We are looking forward to see "Half-Life2".

"Normal map" is mostly used for rendering textures of rocks. A concavo-convex expression of geographical feature is rendered by bump mapping. To see the technics, we have to install more than 128MB of VRAM.