Digital Foundry Article Technical Discussion Archive [2011]

[Dungeonscaper]

I would have liked to see a performance comparison between console and pc.

But PC performance is so varied. I think you mean you would like to see what spec computer would be needed to run at the same framerate with similar graphics features and resolution as consoles.

 

[Richard]

Nope. I meant what I said. I don't want to know which PC runs console Crysis. I want to know the performance characteristics of both the console and pc versions (which scenes are more demanding, how big a drop they are from the average crysis scene, etc.)

 

[Laa-Yosh]

It's fairly standard practice to store 2-component normal maps (as long as they are in tangent space). On Xbox and PC the best option is DXN/BC5, while on PS3 you have to live with DXT5nm.

I think we should take into account that Rage uses a compression that's far more efficient (some kind of HD Photo derivative). It doesn't make much sense to use some sort of pre-compression on the normal map data; and it'll probably get transcoded into some 2-channel compression for the GPU.

Alternatively you can store 1-channel hightmap and reconstruct the normal during streaming or in the shader.

That would give far, far worse quality, especially for characters and such. What you describe is basically the traditional method of bump mapping, as invented by Blinn AFAIK.

As to specular, if you don't need to have exposed color metals like gold and copper, and other special case things like oil spills, you can get away with monochrome specular intensity.

Yeah there's always room to cheat and optimize, however none of the above solutions can beat baking in the shadows and highlights and removing normal + specular channels from the map completely

I haven't played Rage yet, only seen videos, and while it does look "painterly" I do think that it's sort of subpar to ship a diffuse-only game in 2011.

Diffuse-only just for the environment, and how exactly is that subpar compared to a gazillion other games out there? Fully dynamic lighting and shadows are still the exception IMHO.
More importantly, what exactly would dynamic lighting add to the player experience in Rage? I'd prefer dynamic specular too, that's a big sacrifice, but the rest is just not important at all.

 

[Tap In]

Tech Analysis: Forza Motorsport 4 October 18th, 2011


Image comparison FM4/GT5 spec 2

 

[Rangers]

It's remarkable how similar the two games look, really.

 

[AlNom]

Next gen is gonna great.

 

[kagemaru]

Was discussing the RAGE face off with someone and he claimed that the ps3 is at a handicap when running 60fps games due to the synchronization of Cell<->GPU.

This is wrong right? I recall reading about some added latency due to this but would it be enough to deter developers from using the Cell to help aid the GPU in a 60fps game?

 

[Rangers]

Next gen is gonna great.

Where did this come from???

I'm guessing you have inside info too since even I was able to find out a little

But yeah, some of those terrible ground and grass textures in the Forza/GT5 shots once again reenforced just how much is still left to improve next gen.

 

[(((interference)))]

Despite the lower trackside detail, the lighting in GT5 still looks far more realistic than F4.

Is this just a artistic failure on Turn 10s part or are there technical reasons for the difference?

 

[Laa-Yosh]

You need the proper tech to enable your artists to do realistic lighting. I have absolutely no idea how either games' internals work but I do agree that GT5 is still king in this aspect.

 

[Reiko]

I want to see The Ring in Forza 5/GT6 with stormy weather, lightning, and furiously blowing trees at night. Talk about scary.

 

[djskribbles]

The Ring in rain is scary enough in GT5.

Forza looks more pleasing to the eye with it's vibrant colors, but I agree that GT5 looks more realistic. Forza 4 definitely looks considerably better than Forza 3.

 

[Brad Grenz]

Despite the lower trackside detail, the lighting in GT5 still looks far more realistic than F4.

Is this just a artistic failure on Turn 10s part or are there technical reasons for the difference?

Yeah, watching that side by side video Forza 4 looks like a really pretty videogame, while GT5 sometimes just looks real. Ironically, it's things like the added high frequency texture details that make Forza look cartoonish. When you're driving a car, at that distance you aren'y really seeing every pebble in the asphalt or every blade of grass. Forza also has that weird glossy highlight on the ground that screams "hey, shaders!", not "realism". I think Turn 10's emphasis was on making things look fancy, while Polyphany spends all their effort making things look real.

 

[patsu]

Gaffers are also saying the AI cars don't reflect the environment dynamically (or perhaps use a simplified method).

e.g., http://www.abload.de/img/forzamotorsport4_careeh7bj.gif

(Blue car should show a reflection of player's car passing by ?)

 

[djskribbles]

I agree with most of his points. Some of T10's art/design choices still make it look a little too vibrant and flashy IMHO. I do give them a lot of credit for the jump they've made over Forza 3, and the fact that they've added more cars per race while maintaining a solid 60fps and no tearing (I had my doubts).

 

[Nesh]

Gaffers are also saying the AI cars don't reflect the environment dynamically (or perhaps use a simplified method).

e.g., http://www.abload.de/img/forzamotorsport4_careeh7bj.gif

(Blue car should show a reflection of player's car passing by ?)

hmmm it appears that the AI cars indeed use a simplified method. The player car does reflect more from the scenery than the AI cars. The AI cars probably dont even reflect the scenery?
Even when they pass below that "bridge" only the player car reflects it. The other cars dont seem to reflect that or any of the scenery objects.

That said the player car at leasts has higher resolution reflections than what is found in GT5 and also the other cars are being reflected on the surface. In GT5 there is a smaller drawing distance in the reflections and cars are not being reflected, but all cars appear to have consistent reflections unlike F4 which appears to have high quality reflections only for the highlighted car

On another note, F4 visual direction is made to show off the beautiful tech and tries to impress by "exaggerating" its effects with any given choice, whereas GT5 is more "grounded" and targets a more realistic look. Effects are kept at a moderate level unless necessary. The GT5 vs F4 video in DF shows that clearly. A very common example is how F4 demonstrates the sun effcts and its rays at any given chance, while GT5 keeps it at a minimalistic look comparatively and limits how bright it is depending on track and position. F4 is more artsy.

 

[Shifty Geezer]

You need the proper tech to enable your artists to do realistic lighting. I have absolutely no idea how either games' internals work but I do agree that GT5 is still king in this aspect.

I was wondering, GT has had it right since GT3, as best they could on the hardware. Is there some formula that they've developed for car shading and this is used, or is it artists having to work every model somehow? I'm thinking there must be a guy/some guys at PD who came up with the car-lighting-formula they use and it should be reproduceable. Offline car renders are easily photorealistic. Have PD just managed to simplify the techniques effectively so it looks convincing in realtime?

I guess like Coca Cola and Heinz Beans, the secret ingredient will never be known!

 

[KKRT]

Is there some formula that they've developed for car shading and this is used, or is it artists having to work every model somehow?

Cant be an artist, with dynamic lighting and ability to colour every car with more than 300 paints, they just couldnt do that.
I wouldnt be suprised if they have their method patented


Ps. Transparency object are much better handled in FM 4. Is it because of IBL, or their have worked at it separately?

 

[Scott_Arm]

The only thing I don't like about the look of Forza is the sheen on the roads, grass. You can get that on real roads, but it doesn't look anything like it does in the game. It looks more like winter driving here, if the roads are covered in ice.

 

[Tap In]

The player car does reflect more from the scenery than the AI cars.

yes the player cars reflections in game are very well done and given that the default (and preferred) view in game is cockpit or hood cam, the ai reflections are a non factor comparitively. Where as the player car has been given most of the attention as that is where it is most evident in game rather than studying gifs or screenshots.