Why RE4's lighting may be the GCN's Best

[Qroach]

Li Mu Bai wrote,

"The results of global lighting can be computed in three different ways: per vertex, per pixel using emboss mapping, and per pixel using bump mapping. All three of these methods come in two variants one with self-shadowing and one without."--Florian Sauer & Sigmund Vik http://www.gamasutra.com/features/20021002/sauer_pfv.htm

And you believed somehow that the PS2 was capable of more?

Um, where did you get that idea that I thought the PS2 was capable of more?? That's not what I meant at all. From what you posted the gamecube is capable of more with the lighitng then I could recall, so I stand corrected on the vertex lighting only comment, it's just that you rarely see any game on gamecube with mor ethan a few objects using bump maps.

SH3? Vertex lighting. If anything, the PS2's lighting would be primarily all vertex.

Yes of course PS2 is vertex lighitng, Where are you getting the idea I though it was more? I didn't say or even imply that the PS2 was more capable in this area. I was merely talking about programable "Transforms" not necessarily programmable lighting.

It doesn't matter how "programmable" a system is if it's the weakest hardcoded function wise of the three. (which it is) Lighting comes at a higher system resource cost on the PS2 than the GC, & the GC does it at no performance hit as well as in parallel to other features. (although custom lighting is a different beast)

Well yes it does but in the case that I brought up I was specifically talking about transforms. Besides, how often do you see Gamecube games with everything bumpmapped anyway? Rarely if at all.

 

[Qroach]

Ooh-videogames,

Good job with the research, sometimes when you have a fanboyish dislike for another console you do your best to undercut it. I bet Qroach doesn't respond to your post to save face.

Save face on what exactly? Ooh-videogames, if you actually read what I was saying you'd see how your fanboyish dislikes of other consoles has made your post look.

Phil,

You missed his point. The post was an explenation on how the difficulty of a platform can effect the resources a development studio may alocate for it. From what I can tell, he made a good effort in summerizing the differences each platform has, despite him being wrong on the vertex lightning (which he did mention to have heard by an alternative source). Lightning was one example (obviously a bad one), but I think the point about progammability and the rest of the points he brought up are still very valid.

Thank for paying attention to what I was trying to say, for a moment there I was wondering if what I wrote wasn't clear enough, but you seemed to understand my intentions.

 

[Li Mu Bai]

Qroach my apologies, I misread your intent. Though simply if software doesn't feature numerous bumpmaps doesn't mean the system is any less capable, that's always the developer's decision.

 

[marconelly!]

Marconelly, you're referring to the PS2 correct? What 4 pass DOT3 method are you referring to then? (no hardcoded support for DOT3) Gloss mapping?

DOT3 four-pass method described in one of Sony's developer papers. It has not been utilized in a significant game yet, AFAIK, but it's definitely possible. Gloss mapping is what GT3 uses for the pavement in it's night/wet track.

 

[Ooh-videogames]

Ooh-videogames,

Good job with the research, sometimes when you have a fanboyish dislike for another console you do your best to undercut it. I bet Qroach doesn't respond to your post to save face.

Save face on what exactly? Ooh-videogames, if you actually read what I was saying you'd see how your fanboyish dislikes of other consoles has made your post look.

Phil,

You missed his point. The post was an explenation on how the difficulty of a platform can effect the resources a development studio may alocate for it. From what I can tell, he made a good effort in summerizing the differences each platform has, despite him being wrong on the vertex lightning (which he did mention to have heard by an alternative source). Lightning was one example (obviously a bad one), but I think the point about progammability and the rest of the points he brought up are still very valid.

Thank for paying attention to what I was trying to say, for a moment there I was wondering if what I wrote wasn't clear enough, but you seemed to understand my intentions.

I post that just to mess with you. But I don't hate any console or who's behind it. Actually I play alot of Xbox, PS2 not much because the controller is to small.

 

[Li Mu Bai]

Marconelly, you're referring to the PS2 correct? What 4 pass DOT3 method are you referring to then? (no hardcoded support for DOT3) Gloss mapping?

DOT3 four-pass method described in one of Sony's developer papers. It has not been utilized in a significant game yet, AFAIK, but it's definitely possible. Gloss mapping is what GT3 uses for the pavement in it's night/wet track.

It must be too impractical (hardware resource draining wise) to utilize (esp. w/out hardcoded support) in a real-time gaming environment, otherwise some developer (Konami at least) would've incorporated it by now. 4 passes for DOT3 alone? This & other game necessities (multiple textures, lighting, etc.) would absolutely kill both the frame & fillrates Marconelly.

 

[_phil_]

5 passes Dot3

 

[Li Mu Bai]

5 passes Dot3

This illustrates my point even moreso.

 

[jvd]

How many passes for dot 3 on the xbox and cube ?

 

[wazoo]

DOT3 four-pass method described in one of Sony's developer papers. It has not been utilized in a significant game yet

why significant ?? Can you name an insignificant ps2 game with DOT3 bump mapping ??

 

[Tagrineth]

How many passes for dot 3 on the xbox and cube ?

Isn't it essentially 'free' except for the need for extra texture layers on Xbox?

And GCN doesn't do dot3 IIRC, just EMBM (results are comparable anyway so it doesn't really matter much).

 

[Qroach]

Dot 3 bump mapping and EMBM are very different types of bump mapping.

 

[Li Mu Bai]

How many passes for dot 3 on the xbox and cube ?

Isn't it essentially 'free' except for the need for extra texture layers on Xbox?

And GCN doesn't do dot3 IIRC, just EMBM (results are comparable anyway so it doesn't really matter much).

How many times must I post this?

"The results of global lighting can be computed in three different ways: per vertex, per pixel using emboss mapping, and per pixel using bump mapping. All three of these methods come in two variants one with self-shadowing and one without."--Florian Sauer & Sigmund Vik http://www.gamasutra.com/features/20021002/sauer_pfv.htm

Potential Algorithms
Technically many shading methods work on current generation hardware as on the Nintendo
Gamecube. These methods include (but are not limited to):

dynamically lit polygons with global and local lights specular highlights
illumination maps
reflection mapping
emboss mapping (shift and subtract of a height field)
bump mapping (per pixel calculations for diffuse, specular and reflective components)
projected shadows
self-shadowing
shadow volumes
projected reflections
layered fog
polynomial texture mapping
displacement maps
multiple texture mapping
custom dithering

You are incorrect my friend, it performs both & they are very different as Qroach said.
http://www.gamasutra.com/features/20021002/sauer_pfv.htm

 

[Fox5]

Oooh....for some reason I like displacement maps....didn't wave race:BS use them?

 

[Qroach]

So where does it list dot-3 bump mapping?

 

[Li Mu Bai]

So where does it list dot-3 bump mapping?

Could you list for me then another form of bumpmapping Qroach defined as such?

Method 5: Bump Mapping GC=
Visually better results can be achieved using “realâ€￾ bump mapping as supported with the indirect texture unit. Using this method the hardware computes a normal per pixel and uses that to lookup different textures including a diffuse light map (containing all directional and ambient lights), an environment map and even a specular map. Thereby all those shading effects are computed correctly in a bumped way. However, since the global lights are now fetched from a texture instead of being computed by the lighting hardware, the texture needs to be generated dynamically as soon as the camera orientation and/or the lights change (again, one can find an example on how this is done in the demo section of the Nintendo Gamecube SDK).

In addition, the height field needs to be pre-processed into a “delta U/delta V textureâ€￾ (which is an intensity/alpha texture with four bit per component) and therefore needs (without further measures) twice as much memory for texture storage than the emboss mapping method.

The delta-texture is fed into the indirect unit where it is combined with the surface normals, describing the orientation of the bump map. In the last stage of this three-cycle setup, the diffuse light map is looked up and the result is the bumped light color for the global lights. Note that the local lights are still computed per vertex (because they have a location and the normal used as input data does not give this information) and are added later in the texture environment.



PC Dot3=Take a height map as input - this would be a file that contains numbers that correspond with a certain heights.
Internally this height map is translated into a slope map. This means that the slope is calculate along the UV parameters (the x and y parameters of the texture and bump map). This is done quite simply by taking the height values and subtracting them from each other to indicate the change in height in u and v directions (of course normalised). These perturbations give the change of the normal relative to a normal perpendicular to the base polygon.
Now when doing the light calculations you do a dot product between the light source (direction and intensity) - the normal of the plane and the perturbation in u and v directions. The result is a changed light intensity calculation that takes into account the bump map (through the slope values).

Well, I'll be waiting Qroach. As Perturbed environment, blend, & pre-calculated bumpmapping do not match the definitions listed above.

 

[Qroach]

Well, I'll be waiting Qroach. As Perturbed environment, blend, & pre-calculated bumpmapping do not match the definitions listed above.

Quit acting like a jerk. it was a simple question.

 

[Li Mu Bai]

Well, I'll be waiting Qroach. As Perturbed environment, blend, & pre-calculated bumpmapping do not match the definitions listed above.

Quit acting like a jerk. it was a simple question.

I wasn't trying to act like a jerk, ease up Qroach.

 

[cybamerc]

jvd:

> How many passes for dot 3 on the xbox and cube ?

Single pass.



Tagrineth:

> Isn't it essentially 'free' except for the need for extra texture layers on Xbox?

Nothing is truly free or it would be used more. IIRC a dot3 blending operation takes two cycles on the Xbox which sounds fairly cheap but there has to be some drawback or it would be used more.

> And GCN doesn't do dot3 IIRC, just EMBM

It does both but EMBM is faster (the reverse being true for Xbox).



Li Mu Bai:

> How many times must I post this?

EMBM is true per-pixel bump mapping. It's also what Factor 5 uses in RL (in addition to vertex lighting and emboss bm).

EMBM is actually used quite a bit in Cube games but mostly for traditional effects like water and heatwaves. It's too bad because it's works just as well for other surfaces.

 

[Tagrineth]

Tagrineth:

> Isn't it essentially 'free' except for the need for extra texture layers on Xbox?

Nothing is truly free or it would be used more. IIRC a dot3 blending operation takes two cycles on the Xbox which sounds fairly cheap but there has to be some drawback or it would be used more.

I didn't say it was free, I said it was free except the need for extra texture layers which takes an extra cycle (DOT3 needs three layers, NV2x only does two in one cycle). Or is the second cycle you mention an additional loss?

> And GCN doesn't do dot3 IIRC, just EMBM

It does both but EMBM is faster (the reverse being true for Xbox).

'kay, I stand corrected. Hence why I said "IIRC" (If I Remember Correctly) in my comment about what GC supports. Jeeze... everyone here needs to relax before ramming info down people's throats angrily.

EMBM is true per-pixel bump mapping. It's also what Factor 5 uses in RL (in addition to vertex lighting and emboss bm).

EMBM is actually used quite a bit in Cube games but mostly for traditional effects like water and heatwaves. It's too bad because it's works just as well for other surfaces.

I guess this is why I forget that GCN supports DOT3, because EMBM gets the same result and is faster on the little cube.

Actually it seems to me that EMBM can do everything that DOT3 can, plus additional effects that I have yet to see DOT3 do.