• "Top Ten Tips of Texturing"
    CGSociety Tutorial, 2 September 2008


    We dig into the Vault for another look at one of our more popular tutorial features. Jeroen Maton walks us through steps he found to help with the creation of great textures.
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    The main goal of this article/tutorial is to give you a few hints and tricks that might help you to make your own textures look better. What you'll read are things other people taught me, or that I had to discover for myself. They are not the only way to handle some of the problems, but over the years I've found that these work best.

    Material definition is a term I use quite a lot. Very often someone posts a texture that looks weird on the model, but looks even worse if you look at the texture sheet. In the end it shouldn’t really matter if your texture sheet looks 'good or bad', as long as it looks good on the model.

    However, a good way to check your texture is to look at your sheet, and see if you can recognise what material it is (ie metal, rock, rubber, etc), or what part of the model is unwrapped there.

    When working on current and NextGen materials (with all the exotic maps and effects) this is not always possible. Nevertheless, if you can recognise the material then there’s a big chance that it’ll look good on the model too. If you can’t, then there’s a very big chance that you see something as metal while in fact it’s nothing more than random colors and pixels.

    (Pure photo sourcing is something that can easily cause this, but more on that later.)

    Apart from the a good diffuse map, a proper specular can help a lot as well. There are tools that can generate specular maps for you, but they don't give you enough control, especially when you're working with different material types in one texture, or with bright text.

    Nothing beats Photoshop if you want to create specular maps.
    This way you can use masks and mask areas that you don't want to affect. If you have white text in your texture for example, the masks will come in very handy if you want to tone down the effect.

    The picture above shows you how you can create a specular map for a simple two material texture, with concrete and metal. Both have their own level correction. You can use brightness/contrast instead of Level correction for this too, but adjusting the levels gives you a bit more control.

    When working on a texture, it’s a good idea to start with a base material. If you’re working on metal, create a solid metal material. If metal is damaged all over, you can get those in your base.
    It can be a good idea to save your base textures. This way, when you need to create a similar texture, you only have to take the base texture you have and build on that.

    This can come in handy when you're working on a set of props or buildings that all need a similar look. Starting with a base material for every material type in your texture can help you to make a good material definition. When every part has a proper material, then you can start adding details.

    Something a lot of people tend to forget in their textures are subtle details. These are things you don't notice at first glance, but make a texture or object interesting to look at.

    Depending on the style and theme you can use a minimalist style, or go to extremes with the detail. It is your job to give the viewer something interesting to look at. Subtle details are perfect for this, and they can be everything.
    A sticker, some worn paint, rivets, bolts, someone that wrote something with a black marker, mud, oil, anything. But the key is to keep it subtle. If you go overboard with this, it'll lose it's power.



    The prop above made by Jonas Salvador is a great example of how to put details to good use. As you can see, the diffuse is loaded with details, and most of them you don't notice at first glance. There are bits of tape, stains, stickers with text, scratches, rivets, tags, etc. Details like that make 22 triangles interesting to look at.


    Take care. Some people like sharp and crisp textures, others like to leave a little bit of blur in them.
    Personally I prefer the sharp and crisp textures, so I always do a sharpen pass on my entire texture.

    Basically I make a copy of your entire texture, paste it at the top of the layer stack, and do an Unsharp mask pass on that layer (despite the oddname it will sharpen your texture).

    This way you don't mess up your original texture. I prefer to use the Unsharp mask filter over the normal Sharpen filter. Unsharp mask will give you a control menu that can be very useful to keep the effect under control.

    It's very tempting to use sharpen too much, which will cause all kinds of artifacts on your texture.
    The first image is the original texture. This is how it looks in Photoshop without any correction.
    The second image has a single unsharp mask pass at 70%. The details in the paint and the scratches pop out nicely.

    That highlight on the horizontal edge is very noticeable now, but you could tone that down a bit. (Do this in your original texture and redo the unsharp mask proces, this way you'll always end up with a complete sharp texture, and it'll keep your .psd file clean).

    The last one clearly has artifacts that you don't want. The white is too dominant, there are bright orange pixels at the border of the paint, etc. You really want to avoid things like that.

    Avoid using photos in your textures, in such a way that they are not properly processed. It's a very rare thing when you can paste a part of a photo, without having to add or remove details, or to let it fit your UV clusters.

    I'm not saying it's not possible. If we look at some of Stefan Morrell's work then you'll see that he does this very well. However, from what I've seen on Game-Artist.net it is sometimes tempting for a beginner artist to use a lot of photos for their textures, while they probably should have a look at other techniques to create a base texture.


    With Tip #5 in mind, using photos isn't always bad. Photos are excellent if you want to add small details.
    Small anomalies that break the surface, and give your texture the look and feel like it has been used.
    The best way to show you the effect is to show you the same piece of texture with and without photo overlays.

    The best way to get a good effect is to go through all of Photoshop's blending modes and to see which one is working well for the photo you picked.

    Overlay and Vivid Light usually work alright, the rest really depends on the picture but very often give a blown-out effect. One thing to keep in mind when you're doing this is to keep it subtle.

    These are small details, things that the viewer should not notice at all. Another thing to keep in mind is the scale of the details. If you want subtle paint damage, like on the second door texture, make sure that the scale of the details is the same as the scale of your object.
    If not, it'll look out of place, and the viewer will notice that something is off.

    For a better overlay effect you can tweak the "blend if" options on each layer. This is useful if you have bright or dark areas that mess up the effect. You can smooth them out with this option. If you hold Alt while dragging the sliders you'll split the slider up, and create a smooth transition of what is blended, and what is not.

     




  • One way to create dirt has already been covered, and that's photo overlays. Those are great for general wear and tear on your texture.

    If you want small specific details, you'll need to use other techniques. Below are a two techniques I frequently use, one for dust and dirt, and one for rust.

    Dust and dirt can be done very quickly with a solid brownish layer and a layer mask. Simply put the dirt layer at the top of your stack, and paint with a low opacity and flow. You can spice things up by changing the blending mode, or to filter your dirt layer. (add noise for example).
    This will break the surface somewhat if the dirt becomes too visible. Once again, subtlety is the key to success.

    Rust is a bit more tricky. The thing with rust is that it's very random and undefined. Other than the placement and how it leaks, there's hardly any logic to it.

    I used to handpaint rust, but it always had a bit of a cartoony look, and I was never able to get crispy rust that looks convincing and real.

    That was until DennisPls shared his technique with me, which I've been using ever since. It's basically almost identical to regular photo overlays, only here you only use a small part of the texture.
    You clean the edges with a mask so that it blends nicely with your base texture. Matching scale is very important here.

    Good damage placement only requires one thing: logical thinking. If an area is likely to be hit by another object (green arrows), or by moving parts, then logically there will be some damage in that area.

    That can be chipped paint, scratches, rust, etc. If an area is clear from being hit by an object (yellow arrows), then there will be a lot less damage to that area.

    There is a sure chance that you'll find dust and dirt in such an area. Also, areas that are rubbed frequently will show worn off paint, scratches and if they are metal they will shine more.

    This doesn't only work for small borders. If you go big, the same rules apply.

    The front of the forklift (1) is the area that will suffer the most, and will therefore have more damage than other parts.
    The lower part of the side will stick out most, so the biggest damage will be done there. The wheels (3) don't need any comments at all...



    I hope that some of these points can help you with your textures, and that you learned something new.

    Don't forget that they are just simple guidelines.
    They are not 'stick to' rules or workflows.
    I can only encourage you to try as many things out as possible.

    Because only by trying things out will you get a better understanding. Which can only lead to better and faster texturing.
    Like many others, I started as a gamer, and soon wanted to build my own maps and levels.

    The lack of the right props for my scenes bothered me a lot.
    I touched base with Game-Artist.net and after two years we were adopted by CGSociety, and that's where we are right now.

    The main purpose for this article is to make a summation of all the comments that are frequently made at Game-Artist.net (and elsewhere, no doubt). It's not the Holy Grail of Texturing, but it can help you out with issues that frequently occur, and are easy to fix.

    Related links:
    Jeroen Maton
    CGPortfolio
    Game-Artist.net


    Discuss this article on CGTalk

     


    While the use of AO maps is not always required when using normal maps, and with engines being able to render AO in realtime, the advantage of baked AO maps is sometimes underrated or forgotten.

    AO maps are a great way to give your texture that extra bit of depth, and it'll make your model look less like CG, and more like something from real life. (The lack of good GI is in many cases the thing makes something look fake).
    Some people use advanced GI settings to bake their AO maps, but in many cases that's not really necessary. Even 'simple' indications of shadow and light will make a huge difference.

    As hard as texturing can be, it can be even harder if you don't think when you are unwrapping your model.

    Nobody will ever split a face UV cluster in half, and place those two halfs in different places on the texture, yet when people work on props the weirdest UV clusters can emerge.

    If you think about how you will texture your model while unwrapping, you will most likely avoid "bad" UV clusters, and save yourself a lot of time and frustration.

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