Trying to steal Vray's thunder.
I'm gonna wait for Steam version
We’ve been lucky to have a chance to talk to Ana M. Rodriguez about her work with the material production. She gave a detailed talk about her workflow and described the way she upgraded the materials of Rapture.
My name is Ana M. Rodriguez I’m a CG Artist specialized in Textures and Shaders, I’m currently working as a freelancer for the company Blind Squirrel Games and the last project I’ve been involved in was Bioshock The Collection. Prior to this I worked on Castlevania: Lords of Shadows 1 and 2 and also had the opportunity to collaborate on the project for Nintendo 3DS, Castlevania: Mirror of Fate.
My academic training consists of a Fine Arts degree completed with a Master in Creation of Videogames at the Universitat Pompeu Hw(Barcelona).
When I face the challenge of having to “dress” an environment, normally I start with some references, mostly real life photos (concepts sometimes). The pictures of what you want to represent are a great help to observe the details and variation, as well as the original forms of alterations and colour gradients, types and shapes of dirt, stains, etc. All that complements the image.
At the end of the day if you want to give an artistic or stylized touch, you need to start from what you want to “imitate” in the real world (if that is the artistic intent of the game). However, for the project of Bioshock, I had to start from an existing texture so the process was very different.. I had to be respectful with the original, follow its predetermined pattern (in the example of a tile bathroom: emulate the number of tiles, repetition, the type of dirt that was generated in the original), trying to follow the dirt pattern as well but improving and taking advantage of the new resolution of the texture.
A lot of people confuse that a remastered texture looks more “new” than the original because it looks sharper. Usually when you are remastering a texture you are starting with a lower resolution image. Smaller size means less defined and less clear details that you will have to figure out in the next step. Being able to work with bigger size textures allows you to remove the noise that the original texture had because of the compression and lets you add those new details but differentiating the dirty areas from the not dirty ones. So the result is that where the original was clean the remastered is cleaner and where it was dirt the new one is dirtier. You are able to generate more “visual clarity” thanks to the bigger resolution allowance.
Challenges in Creating Complex Materials
The biggest challenge to me when I’m creating textures is to get the desired finish (in Bioshock’s case that mixed look of “realistic and stylized” for example), and get it fit with the rest of the environment textures look .
You have to be aware that what you will see is not an isolated texture, it’s a tile that will be part of an environment and it needs to give that feeling of continuity and consistency throughout the level. When you’re freelancing this is harder to get, because you aren’t that aware of what the rest of the team is doing, but when you are involved within the team such integration is much easier. That was my case when working on Castlevania series. Having a dedicated texture art team is a huge benefit. This allows you to work as if you are almost a single brain, if you complement that with a very clear art direction, all textures ended up looking as if they were all made by the same person. That pipeline contributes to give more credibility to the environment and much more consistency to the art.
Keep in mind that I’m talking about gloss/specular texture materials. In the case of PBR, the integration should be now easier, because if a material is following its presets (whether or not the material is reflective, which percentage of roughness, etc) and responds to the light in a “physical” manner so to speak, it should fit into any environment and behave correctly (assuming that everything is done according to the specified charts).
On another subject, in terms of material efficiency, it is important to start with the most basic shapes and end with the most complex. For example, if it’s a stone block texture, start by the blocks and finish adding moss, fungi. Always go from the general to the particular of that material. I think that advice applies regardless of the method used to develop a texture (either Photoshop, Quixel, Substance etc). Analyze first what you want to do roughly (large brick wall) and then go to the individual and specific details (worn, broken, moss, blotchy, etc.). If you also want to mix it with another texture or in the same texture with a different element (band of decorative metal as in the case of Bioshock) you have to take into account that this element is part of the wall itself, it has aged in the same way and it has undergone through the same weathering conditions: rain, humidity, dust, etc. So, in order for the texture to be natural and to have consistency you must understand that and not to think about them separately but as whole.
Adding Damages to the Tiles
To achieve a texture rich in different tones it is important to look at the reference, search for the uniqueness of that particular tile, study what makes it special and different from the rest (what types of cracks are generated when it’s broken for example), etc. Always try to be consistent with that reference but also try to enrich it at the same time. When I say that we must give richness I mean it’s not enough just to stamp or copy a photo. That’s just the start. Try to do something believable and interesting with it at the same time.
If the environment that the texture will be part of is something more stylized you should try to do more interesting shades and hues. Photos of textures taken from real life with a neutral light are perfect for the purpose, which means they are very useful as a base texture or as inspiration, but they used to be boring and monotonous. For this reason, texture art is a constant “artist-eye” work, also to go further and find those tones that you don’t observe in your reference and try to translate them into your texture. One trick that works for me really well is to try to capture more things in the specular map than those who appear in the diffuse map. For example, a tile may have a scratch not seen in the diffuse texture just yet but when light falls on your tile, that scratch will be noticeable. That trick that produces light on the texture will bring you much more richness than if you decide to include all that information in the diffuse map, also because it is likely that in that case, you’ll see too much noise and you won’t be able to barely appreciate the difference.
A very good trick to get aging a texture is to use an image or various images of random dirt that has nothing to do (absolutely nothing) with it and overlay it with some layer blending mode (soft light for example). For example, in the case of the bathroom tile I chose a picture of stains in a wall. This allows you to yellow the overall hue texture without adding too much noise to the image. In addition to this, you can add another photo of a wall with spots or leaking and mask it up to cut those rust spots and place them above the image to give the feeling that the water has been sliding down the wall. This is a good idea unless you have the opportunity of using decals or material blends. In that case the method is something completely different and you have to avoid this kind of details in the base tileable texture.
The key to made reusable materials is the use of decals or material blends. When I talk about material blends I’m referring to a realtime shader that allows you to blend different materials (chosen from a defined library) using monochrome masks, vertex colors, height maps, etc.
The idea it is to try not to make them too unique. In order to make a good tiling texture in all directions you have to avoid including neither horizontal nor vertical detail that spoils the pattern (vertical leaking for example). If you want to have spots, you have to make sure that the stains are not that obvious to make the pattern too noticeable. With the cracks is exactly the same, you have to try to make them more “organic”.
The question with the decals is, if you are allowed to use them you have to try to add all the distinct variations on the decals or to use another textures to blend. This will give you the ability to use the material as a base and generate enough variations only with decals or material blends. In production this will save you a lot of time by not having to create the same brick wall 3 times with subtle variations.
For example, let’s say that the level takes place in a swamp. Create some stains deterioration or leaking spots, or green moss in a couple of decals. Take your tileable brick wall and make a blend texture with that moss, or make an alpha and use it as a decal. In another level the theme can be a desert and you can have the same brick wall material. By just changing the moss decal by another sand decal or whatever you will be able to achieve texture variation, save you an incredible amount of production time and, more importantly, maintain texture memory lower.
Avoiding Artificial Look
As I mentioned before, in this particular case the best idea would be to have a concrete wall and place those broken bricks with an alpha (or have a diverse set of them). This way you would avoid the repetition and the impression that the wall seemed too artificial.
For me the most important thing when creating a texture is putting all your love and care on it, otherwise you can end up with a boring “standard”/plain texture. If you are using photo reference when creating a texture, you cannot just grab the photo and stamp it as I previously said. When using Zbrush you are in danger of focusing too much on authoring a very exaggerated normal map, undermining the rest of the channels and ending with a ordinary/uninteresting material.
Now, with PBR and all the possibilities that the new software give us with preset materials, we are in the same danger: mediocre, lifeless or repetitive materials. So relay in your eye, in your good taste, in your references too, try to make it more appealing. Don’t be conformist with some random material of a library… go beyond that.
Materials must behave according to their properties, yes, that’s absolutely true, and that’s what PBR gives us, but the artist has to make them interesting, rich in tones, shades and hue, pay attention to the details and go beyond the conventional or boring. Yes, maybe that mailbox that you are seeing is made of red paint on metal but our responsibility is to observe the discontinuity in the bubbles, make some cracks which allows to see the metal underneath or add some rust on the borders due to the harsh weather.