Preface: I meant to do this a long time ago. Back in 2008 when Blizzard unveiled the first footage of Diablo 3, there was an uproar over it. I thought it looked sub-par myself, and felt like writing about it, but 4 years later I get around too it. Why? Because in every discussion about Diablo 3 nearing it's launch has seemingly erupted into a flamewar over the graphics. I waited for final judgement until after release, since I did not get into the beta, so here are my thoughts as to why the controversy exists, and what specifically is the issue with the visuals and style. So I felt like 'sperging out this afternoon and trying to see if I could clear up the debate for once. I feel I should do this so the rest of you don't.
Moreover I feel like most of the complaints are very legitimate going back to 2008, but rather people have not actually explained the grievances clear enough. When the first footage broke for example, much of the fixation was on the rainbow that appeared on screen. For me this was a non-issue, it was merely a tiny bit of icing on a much larger cake, as a rainbow is nothing more than an optical effect like lens flare. There was something very wrong with the visuals but most probably could not exactly explain in detail what. Defenders even thought the critics felt the game wasn't "Grimdark" enough for having colours (ironic considering the term Grimdark comes from the very-colourful Warhammer 40k series).
The emphasis on the "colourfulness" of the game and the rainbow made Blizzard suspect people were simply wanting a game more monochromatic and dark, and caused the art team and supporters (even Penny Arcade jumped in their defense) to launch at the detractors as if they wanted the game to be visually dark and gruesome, which was largely a strawman opinion.
The two sides never saw eye to eye in their criticisms. For one thing, what was most off about the Diablo 3 footage was specifically the visual and graphic styles, not the content of the game. A very important note, and the one thing you should take away from this if anything, is that the actual content of the story and game was not what was criticized, as some defenders (including Blizzard devs) have claimed, but purely the aesthetics themselves. And the aesthetics themselves could not and can not be fixed by changing the content of the levels or story. Apparently some devs went back and added more bodies and grim aspects after criticism, which is meaningless to this controversy. For the debate on how the game looks cartoonish, it does not matter if there is one dead body or a thousand on screen.
Most amazing is how Blizzard has struck back by creating a joke level full of rainbows and ponies. It's a funny level, but at the same time Blizzard did not listen to the criticism of the art style. In their defense, as I discussed earlier, a lot of the criticism was not detailed and thoroughly explained enough which led perhaps to them not knowing specifically what was wrong with the visuals. What's notable is that Blizzard has a history of using Alpha footage using older engines and styles. The early Starcraft Alpha used the Warcraft 2 engine. There was criticism, and Blizzard changed it and created a brand new, advanced engine for Starcraft that was much more fitting. However this time Blizzard changed, they did not really change from the Alpha to release footage even with much more vocal complaints.
Another thing to note is that Blizzard North were the ones who made Diablo 1 and Diablo 2. Their talent has left and so even though their partner company is making Diablo 3, they are trying to imitate something somewhat foreign to them and out of their comfort zone (making Warcraft games). So perhaps for that reason they cannot avoid making new styles that are not Warcraft-influenced.
Most importantly there have been a lot of comparisons with how it looks like World of Warcraft.
The first big problem with the graphics in Diablo 3 is the lighting system. There's been much controversy about it being too light or needing to be darker, but the actual problem us much more specific than that. The big reason this is important is that our brains can tell a lot from lighting and shadows, so a significant amount of the "wrongness" of the Diablo 3 graphics probably comes from its lighting system, even if we don't consciously notice it.
Example of dynamic lighting and shadows in 3D
The problem with Diablo 3's lighting system is it either barely exists, or doesn't really work as intended. In Diablo 2 the lighting system, like any good system, had light only radiating from actual light sources. For the record, yes, Diablo 2 was both a brightly lit and darkly lit game so the issue isn't that one game is too bright overall or too dark overall. Diablo 2 had good lighting (and darkness) because it used lighting effectively. In Act 2 the game was illuminated by a bright sun, in the catacombs of Act 1 it was nearly pitch black. The game's lighting was neither too dark, nor too light, it was simply accurate and realistic. A torch on the wall generates light, the sun generates light, a campfire generates light. Further the playable characters generated light, which radiated out and cast shadows on objects, like they are carrying torches. What this did for the atmosphere was create a "candle in the dark" aspect, which influenced the metagame (characters would need to stick together to generate light, and enemies far off would be hidden in the darkness) as well as simply making the mood better.
Note how in the above shot, the actual sources of light are not whats producing the rooms lighting, but rather the same club lighting seen elsewhere. Also note the bizarre blue glow from below. Kinda reminds you of a radioactive storage facility?
With Diablo 3 the issue is that this system of accurate, dynamic lighting which has been in games since the late 1990's, is completely out of whack. In screenshots like these you can see that light emanates from the most inappropriate of places. In a stone hallway for example lined with torches, the light sources are not what produce any ambient lighting. This poor lighting quality is one of the reasons why people have criticized Diablo 3 for looking like World of Warcraft, since WoW had the same poor and bizarre lighting in its dungeons and areas. This change is one of the biggest stylistic departures from the first two games and one of the biggest eyesores. In Tristram at the start, the lamps on the street emanate what looks to be not light, but an orange blotch of transparent texture, likewise the large fire pit gives off no ambient light, despite being (or should be) the biggest light source in the scene.
This is also present when spell effects are used. Note above how the vividly bright spell effects give off no ambient light, when they should be the brightest thing in the room. Because these bright particle effects do not light up the environment it contributes to the dissociated, cartoonish look.
An example of what a fan wanted:
This lack of light-casting and realistic shadows is, along with the bad use of colours, the major reason the game appears cartoonish. The world seems more fake because things we expect, like light sources actually giving off and casting light and shadows, do not work. This creates a disassociated "floaty" feel to the models as well, as any light that exists appears to pass through them and without solid shadows especially in bright areas, the models appear to not be on the same 3D plane as the ground.
Inappropriate colour
Diablo 3 has often got criticized for being "too colourful", but it's hard to quantify what it means for there to be too much of something like colour. Rather than be to colourful, the real issue is that the game does not use colour accurately. To understand what accurate use of colour means in this case, imagine a photograph of a bowl of fruit. It will be colourful, with yellow from the bananas and reds from the Apples. What Blizzard did however is attempt to draw the same bowl of fruit, but could not get the colours down. The Apple to them is orange and the Banana is blue-green In the first act alone there are several clear examples of this broader issue with the art design, such as the grass textures appearing a strange blue-yellow colour, the dirt appearing blue-brown, the stones under the Cathedral being green, purple or blue coloured in some spots but more brown in others. Diablo 2 had accurate colours for its day, blades of grass actually appeared green like grass should be, dirt was brown, stone was stone coloured. Blizzard managed to use hues and colours for textures and objects that were completely off, which further compliments the "cartoon" look so criticized by fans.
Back during I believe Blizzcon 2008 or 2009, the head of the art team referred to this practice of putting odd, random colours in parts of the dungeon as "mood lighting", as if it helps to lure players towards it. The problem with this "mood lighting" is that unfortunately for the art team, the only place this sort of lighting actually exists really is in places like nightclubs. It's a little strange to imagine that somehow these dark dungeons under the earth have green LED lights going on up above. For the art team's sake, they probably anticipated this would look "creepy" or "sinister" but in reality our interpretation is that it just makes us want to drop ecstasy and get loose.
Bizzare green, blue and purple lighting appears often...
As earlier with the problems in lighting, there are other strange, inappropriate glows emanating from things like brick walls, or "bottomless" abysses, which, because they have no logical origin, look more like engine glitches than some sort of stylistic "feature". This goes further into the textures used for the ground and walls, especially in the first Act. Some fans have tried to explain that the silly glowing effect in the background in the Cathederal level was because of the fallen star, but such effects exist elsewhere as well.
Why is the pit emanating blue light?
Further the colours are too low contrast and lack contrast. Much of the background blends together. This was noted in the first footage. The textures, along with a strange, blurry fog (most apparent in Act 1) makes the visuals muddled and fuzzy. There has been an attempt to fix this with Dark3D but rumours are that mod may be banned.
Dark3D in action, a fan-made attempt to salvage the graphics
Even so, this is a type of art style that is seen in paintings both contemporary and old. The only problem with this is is that this style of painting is largely from the Romanticism era, and the soft, fuzzy style was done to illicit a sense of calm and relaxation from patrons. Contemporary pop-painters like Thomas Kinkade do the same thing with their art to create a heartwarming and wholesome image, something one would expect the Diablo 3 team would have wanted to avoid. The soft fuzzy edges, lack of detail, and morning-dew glistening on the surfaces psychologically keeps us at ease, which is probably quite the opposite of what the Diablo 3 team wanted. I'm not sure if they know of this bit of art history (I learned it back in a class I took) but part of the reason I believe there was so much immediate backlash against the visuals was because fans immediately noted the irony, even if they couldn't grasp what was going on. Their brains were seeing visuals meant to calm, uplift and relax while the developers were trying to show a game that was supposed to be gothic, grim and dark.
The models themselves have been criticized for looking like WoW, and there's solid reason for this. Many models have an "inflated" look to them, similar but not as extreme as those that are in World of Warcraft.
Note the "inflated" look of the chains, similar to how models were oversized and exaggerated in World of Warcraft.
Even the levels themselves have a similar inflated feel, with Cathederal basement's that are as open and spacious as the LA convention centre (and because they lack any real Gothic architectural design as well, has no feeling of being a Cathederal at all). Although few of us will miss how claustrophobic some levels in Diablo 2 were (Maggot Lair anyone?), the comically spacious levels have a cheapening effect on the atmosphere and are a clear holdover from the design of WoW, where even the smallest dungeons were built like they were meant to store passenger airplanes.
Weapons and armour have the same absurd proportions as they do in World of Warcraft. Diablo 1 and 2 had sensible designs based on real weapons. One reason why "accurate" weapon design works better is it tends to actually look functional and deadly, even to people not familiar with them. A sharp silver blade actually looks like it can cut something, while a large, twisted, glowing mess of purple and blue bulges looks like it was manufactured by Supersoaker or Nerf, since we're used to associating harmless weapons with bright colours and silly designs.
This is why the higher-end weapon and armour designs of Diablo 3 look so impotent and are so widely criticized, because they appear laughable and harmless to our minds based on what we know of weapons. For example if someone swung the sword on the right at you, you would
have a far more serious reaction. That's because our brains recognize
that one is a toy (because of its bright colours, dull edges and
plastic-looking construction) and one is sharp metal.
The textures themselves have an issue. While this is explainable by the need to have lower-res texture, however a lot of the visuals lack detail. Blizzard tried to hide the lower resolution. The reason why Diablo 2 arguably had better textures is the textures focused more on detail and accuracy, and were not smudged and blurry. Compare the level of detail found in Diablo 2's second Act, in the city there is lots of damage to the walls, bricks missing, loose boards. This is more excusable to a degree due to sharper textures requiring higher system requirements so some slack is given here, even if the textures are often criticized.
While it's too late to change things, (and more importantly Blizzard really doesn't care for fan criticism anymore), what Blizzard should have done was simply released the game with two levels of graphics. If making Diablo 3 scalable to play on very low-powered PC's and high-end rigs was the goal, it would be no harm to have a more realistic engine with better lighting and better textures be shipped for higher-end computers to use, and the lower-resolution, cartoonish visuals (the kind it currently has) for the lower end computers. This is attainable because other engines and games do the same, even graphical powerhouse games like Doom 3 shipped with optional extreme-low res textures and lighting for the weakest computers to use, while making no sacrifices on the highest-end textures and lighting, all in the same game.
Or even better yet, allowed the mod community to come in and fix the graphics. However Blizzard has yet to really open up to the mod community, which is a bigger problem in itself, considering the mod community is something of the heart and soul of PC gaming.
Been writing this like an hour now and it's way too many words I would suspect. So I will stop here.