Sunlight

The recently released game Marvel's Spider-Man has interiors behind windows in many buildings. This looks great and it seems to be done using a rendering trick: the geometry for the interiors isn't actually there and is generated using a shader. I haven't seen any official statement by Insomniac regarding how they made this, but based on how it looks it seems very likely that they implemented interior mapping : a technique I came up with in 2007 as part of my thesis research. I've never written about this on my blog before so I figure this a good moment to explain the fun little shader trick I came up with. Let's start by having a look at some footage from Marvel's Spider-Man. The game looks absolutely amazing and Kotaku has captured some footage of the windows in particular: As you can see around 0:40 in this video the rooms aren't actually there in the geometry: there's a door where there should clearly be a window. You also see a different interior wh...

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...

While working on the visual style for my weird live performance game Cello Fortress I came up with a new technique for depth of field blur: area based depth of field blur. As far as I know this is not an existing technique so today I would like to explain how it works. The visual style for Cello Fortress is far from finished at the moment, but I decided early on that I wanted strong depth of field blur to play a major role. I had already implemented depth of field blur for Proun (which by the way is coming to 3DS, iOS and Android soon!) and I copied that to Cello Fortress. Proun does not have blur on the foreground, so I added that and tried it in-game. The result turned out to not work at all, as you can see in this image (be sure to click the image for a larger version, since this is difficult to see in these small blog-sized images): click for larger image The problem is that with standard depth of field blur, only one specific distance to the camera is sharp. In Cello Fortress th...

Bokeh is an effect that pops up in a lot of new games. It is one of those effects that makes a game instantly feel a lot more "next-gen". It is also an effect that usually eats up a lot of performance. For Cello Fortress I came up with a simplified version of bokeh that looks really high quality, is very fast to render and even very easy to implement. My implementation also has some severe limitations, but I think it can work really well for many games. Bokeh is a part of focal blur, which is also known as depth of field blur or DoF. DoF is the effect that only objects at a certain distance are sharp, while everything closer and further away is blurred. This is an effect that every lens has, and the larger the lens is, the stronger the blur is. Focal blur has been done in many games for quite a while now, but with the normal DoF rendering techniques the bokeh effect is usually lost. Bokeh means that extremely bright spots grow with the blur and appear as clearly recognisable...

Last week I started the top 7 of my favourite bugs with the numbers 7 to 4. The top 3 is where it gets really crazy. Sit back and enjoy to see how amazingly stupid game development can sometimes be! Click here for numbers 7 to 4 3. Hidden functionality to turn off bugs On one of the platforms Awesomenauts launched on, we had a lot of trouble getting the internet connection between players to remain stable. After a while the ping would always start slowly increasing, until in the end it got too high and the game disconnected. Sometimes this took a couple of minutes to start, sometimes half an hour, but in the end this always happened. We contacted the support team for the platform-specific networking library that we were using, and their answer was that we used too much bandwidth and sent too many packages. So we spent a lot of time optimising, and we managed to half the number of packages and half the bandwidth. However, the problem remained, and they again told us we used too much ba...

The most complex graphics effect in Snowball Earth is without a doubt the snow. As the player walks around and heats up the area around him, the snow melts, forms puddles and finally becomes grass. This is completely dynamic: the player can turn his heating on and off at any point, and the snow reacts correctly to that. The snow even has little piles around trees and rock walls, and these piles lower and disappear when the snow melts. So how did we make this? A slow motion video of how the snow melts around the player. Before I continue, I would like to mention once more that Snowball Earth is Ronimo 's cancelled game from 2008, and that the complete prototype can be downloaded here: Download Snowball Earth prototype (Torrent) So how did I implement this melting effect? The basic trick is that for every vertex, I store the 'meltness': to what extend the ground at that vertex has already been melted. A value of 0 means snow, 0.5 means water and 1 means grass. The pixel shad...

The part that I find most interesting and am most proud of in Snowball Earth (our cancelled game from 2008), is the melting effects. Every piece of the world is frozen and covered in snow, and by walking around with the heating turned on, the player can melt it all. In the prototype this had very few gameplay mechanics attached to it, but just seeing and hearing everything come to life is already so much fun that it could carry half the game on its own. Today, I would like to dissect this effect and give an overview of what went into it. (Spoiler: a lot of custom art by our artists Gijs, Ralph, Olivier and Martijn, and a lot of coding by me). The melting effects in Snowball Earth For those who haven't tried it yet: a couple of months ago (in this blogpost ) we released the entire prototype we made at the time, so you can download and play it yourself. Note that this is a Torrent file, so you will need something like BitTorrent to download the game. Here is the download link: Down...

I had a lot of fun writing the water shader for Awesomenauts , especially since it allowed me to use all kinds of small and subtle tricks to get exactly the right effect. Using shaders creatively to get precisely the right look is one of the things I enjoy most, but it is not a very common pleasure when developing 2D games. So I sneaked in this water effect during a weekend just because I really wanted to make it. Before I implemented this water, our artists weren't really convinced by the necessity of creating it at that point, but once they saw it, they were really happy with the look. :) There is nothing ground-breaking here, but I am quite happy with the specific combination of little tricks I used to get the best water effect for Awesomenauts, so here is a little graphical overview of how I made it! (Raytracing like this in a shader is actually very similar to what I did during the research for my Master's thesis at Utrecht University. My Interior Mapping and volume rende...

I posted about depth of field blur last week and discussing it in the comments got my mind back on the "Bokeh" effect. Bokeh is an advanced form of depth of field blur that is currently used in lots of tech demos to show what the next console generation will be capable of. So that got me curious again as to how Bokeh is made. I have been experimenting with it in Proun and have some nice images to share! Bokeh is the effect that when there is strong depth of field blur, bright lights in the background become bright spots, often visible as circles or hexagons. This is a real lens effect that can also be seen in photographs, and it looks pretty cool, since it adds some definition to an otherwise completely blurry depth of field blur effect. A nice example of rendering Bokeh on the videocard can be found in Epic's Samaritan demo. Although the style and look of this demo don't really appeal to me, Epic shows lots of really cool effects here that they think will be possi...