Sunlight

In my last three blogposts I've discussed the details of various texture formats. Now that we've seen them, it's time for an overview. Below you'll find a big table that lists the properties of a lot of different formats and shows their results. I'll also discuss some final considerations on performance. The important thing here is to realize that there is no perfect solution: every choice has its own drawbacks, so even with the same art style you might end up with different texture formats depending on the platform. These are the main arguments to consider: Quality Size in video memory Size on disk Download size Loading time Framerate Development time Most of these are pretty obvious and I've already discussed quality and size in video memory extensively in my previous posts. The reason I'm listing them here is that it's important to keep in mind that you can mix and match formats for different goals. There are also more complex things that might m...

DXT is the most used texture format in games and it is what we use most in Swords & Soldiers II and Awesomenauts . DXT is easy to use but provides some weird compression artefacts, so a good understanding of how it works is very useful for both artists and graphics programmers. Since DXT is not supported on iOS I will also shortly discuss the quite similar PVRTC format. This is part 3 in my short series on texture formats for 2D games. Here are part 1 and part 2 . Note that DXT is often also referred to as DDS because DXT textures are usually saved as .DDS files. DXT is also known as S3 Texture Compression . There are several versions of DXT. The most versatile type is DXT5, which stores an alpha channel that can be used for transparency. DXT5 uses only 8 bits per pixel, making it 75% smaller than full 32bit RGBA. If no alpha is needed or only on/off alpha, DXT1 can be used, which is even smaller: 4 bits per pixel, making it 87.5% smaller than RGBA. That's quite a spectacular...

After last week's introduction to texture formats we are going to look at palette textures today. Palette textures are an interesting and underused option for 2D games. Using them is quite a hassle since normal videocards don't support them, but for certain art styles they offer high quality and small texture size. Palette formats are similar to GIF files. The idea is that we have a palette, a list of all the colours in a specific texture. In the actual texture we don't store the colour of each pixel, but rather a reference to the palette. If the texture doesn't have a whole lot of colours we can get away with using only 256 different colours. References to these can be stored in 8 bits per pixel, so this format is 75% smaller than uncompressed RGBA. Palette textures are particularly useful for cartoony styles with flat shading, since those have fewer colours per texture. If your textures have more than 256 colours, you can reduce the number of colours. Depending on th...

When making a large scale 2D game like Swords & Soldiers II or Awesomenauts using the right texture formats can make a big difference for visual quality, video memory, loading times and download size. What format works best varies depending on art style and platform and a good understanding of the options helps a lot in making the right choices. This is a huge topic so I've split it into four posts. Today I'll cover the basics. The other three posts will discuss the more obscure palette textures, DXT and finally a comparison table of all the discussed techniques. This short series will get a bit technical at points but I've tried to make it as readable for artists as possible: knowing how your art will be compressed is important for game artists. While the texture formats available for 2D and 3D games are the same, 2D games have different requirements, so it is interesting to approach this topic from a 2D standpoint. Also, 2D games usually don't have things like n...

Good game graphics are not just about being pretty. Equally important is that they communicate well. The richer and more detailed a visual style becomes, the more difficult it is to communicate gameplay clearly. With the amount of detail and variation we wanted in Swords & Soldiers II it was a challenge to make the units, spells and other gameplay objects pop out against the colourful backgrounds. Today I would like to show the tricks our artists used to make this work. The reason this is important is that otherwise it would not be clear which objects are interactive and which are not. For example, is a tree a wall that I cannot pass through, or just a backdrop that has no effect on the gameplay? Ideally these kinds of things are immediately and intuitively clear to the player, without requiring any explanation. Our new game Swords & Soldiers II launches on Wii U on May 21st. The easiest way to achieve visual clarity is to not have any backgrounds or effects. Just a flat-colou...

During the Christmas vacation I read the fantastic book Color and Light: A Guide for the Realist Painter by James Gurney. It contains a number of really interesting ideas about colour schemes, so I was curious how these relate to existing games. I was especially curious about Proun : when creating the art for this game I did not know anything practical about colour theory. I just tweaked the colours until they looked good. Apparently this was successful, since reviewers were extremely positive about Proun's visuals and vibrant colours. How then do the colour schemes in Proun relate to Gurney's colour theories? To analyse this I have developed a simple little tool that visualises the colour scheme in an image. You can download the tool and source further in this post. So let's have look: what are Gurney's ideas and how do they relate to Proun's art? The concept I found most interesting in Gurney's book is gamut mapping . To understand this we first need to know ...

Changing the lighting in hand-drawn art is a challenge. While in 3D games you can simply modify the light, there is no such thing when using 2D assets. In our new game Swords & Soldiers II all the level assets have their lighting drawn in. Of course you can ask the artist the redraw the image with different lighting, but that costs a lot of additional time and texture memory. We managed to re-use our daylight textures to create convincing nighttime levels, so today I would like to explain the tricks used to achieve that goal. Today's post is all about the artistry of Ronimo artist Ralph Rademakers. He uses images drawn by Adam Daroszewski* and Gijs Hermans to decorate the levels in Swords & Soldiers II. Ralph keeps surprising me with the unexpected tricks he manages to pull off with our internal tools . *By the way, note that Adam works as a freelancer these days. He drew most of the level props in this post and you can see some more of his amazing work here . There is ba...