Happy accidents in DiRT: Showdown

DiRT: Showdown, a racing, demolition, ‘hoonigan’ and party game from Codemasters, was recently nominated for its outstanding real-time visuals at the 11th Annual VES Awards. We talk to the senior art director on Showdown, Nathan Fisher, about Codemasters’ approach to creating car and environment assets, rendering and crash sims.

Watch the launch trailer for DiRT: Showdown.

fxg: Can you talk about designing the world of DiRT: Showdown? What were some of the references you looked to, and how did you translate those into the game assets?

Fisher: DiRT: Showdown came about because we felt there was a gap in the market for a true destruction derby style game. The goal was to create a racing game that was all about having fun whilst still retaining that ‘grounded in reality’ experience so it didn’t lose that authenticity we achieve with all our racing games. We started off looking at motorsport events that toured around the world. Redbull Xfighters being one example we referenced for the production, choreography, lighting and pyrotechnics point of view.

Codemasters senior art director Nathan Fisher (above) was one of the nominees for DiRT: Showdown. Also nominated were Peter Asberg, Peter Clark and Julie Mcgurren.

The announcement trailer we produced took this style of event but with choreographed cars so it felt rehearsed but still edgy in the stunts and crashes that were being performed. We also referenced Ken Blocks ‘Gymkhana’; that whole concept of exploring an environment whilst still performing stunts and having objectives felt like it was an interesting balance against the more action racing element.

All the cars are referenced from real life counterparts but with a slight twist to make them look and feel more edgy and appealing to drive. The environments are all real locations which again helped us make this feel authentic and grounded.

fxg: Part of the drawcard of the game is immersing the player in each track. How did you do that? How were lights and lens flares and atmosphere and other elements realized to help ‘sell’ the world?

Fisher: We researched a number of places around the world that we felt it would be a cool and realistic place to hold a festival style event. The Nevada desert festival (the opening to the game) was loosely inspired by the ‘burning man’ festival. The difficulty in making this extreme, barren location feel authentic was to make the assets look temporary, as if the staging had only been constructed for a short time, a kind of one off show. Having depth and parallax to the scene was also a key Art direction; this allowed us to convey this festival concept outside of the main track area.

To try and realize the ‘racing stage’ we kept asking ourselves the question ‘if we were attending this event, what would we want to see’. Choreographed lighting that not only focused on the action but encompassed the whole arena and set the stage for the event. Pyrotechnics that both added background ambience but also having them linked to key gameplay moments to reinforce the objectives of the race. The sound design built tension and reward to the game play. As we started to layer and link all of these effects together you really started to believe that something like this could be a real sanctioned event.

fxg: What were some of the features of the EGO engine that you capitalized on for the game?

Fisher: The improvements made to the EGO engine allowed us to have a much larger VFX presence than in any of our previous games. Focusing on high impact bursts to make the collisions look visually more impressive. Creating interesting background effects such as fireworks, lasers and search lights all combined to immerse the player in that festival feel. Using 3d meshes for particles that included normal and specular maps as well as having the 3D meshes casting shadows all helped push the fidelity of the VFX. The choreography system allowed us to script and create race scenarios which help maintain the race action and keep the player engrossed.

fxg: What was your approach to rendering?

Fisher: During daytime races we use a forward rendering approach with cascaded shadow maps for the sun coupled with baked shadows further away from the camera to allow us to accurately cast shadows from all the destruction and dynamic elements of the game while never running out of shadow when needed.

At night we use a light pre-pass rendering approach to differed lighting to allow us to render all the dynamic light sources in the tracks coupled with support for several shadow casting lights that are used where they will give most impact. In our PC version we made use of a new technique called Forward+ rendering which makes it easier for us to combine our daytime rendering path with more dynamic lights so you will see more effects in the sunset lighting locations in DiRT: Showdown on PC when running with this feature set enabled.

fxg: How were the cars designed and textured – how did you art design interesting damage onto them?

Fisher: Our heritage is in making racing games and here at Codemasters we have a team of very experienced vehicle artists who are highly trained and excel in bespoke vehicle design. We obviously start off with a high level vehicle list that is broken down into the various racing categories. Once this is agreed the vehicle artists begin their design phase for each vehicle, including researching various livery template designs that fit within that style of race type. i.e. a destruction derby livery wouldn’t fit with the more official gymkhana licensed car liveries.

In terms of visualizing the damage for each vehicle, we do have a dynamic texture based system that allows us to localize paint damage, scuffs and apply dirt, all of which build up through the course of a race. This system also enables us to create bespoke themes for some of the racing categories such as the destruction derby style vehicles which have a pre dirt and damage setup using the same mechanics.

fxg: Can you talk about the physics simulations and car-setups used for the game? What were some of the tools used to add extra destruction effects, damage and dust to hits and crashes?

Fisher: When the car handling designers are setting up the car they have access to a large amount of technical data from the manufacturers that they are able to use. However, depending upon the game, the designers can choose to tune these values to make the cars easier and more fun to drive.

The damage model is set up so that our car handling designers can specify the strength of the different areas of the cars and how much they can be deformed by, then, when a collision occurs, finite element methods are used to determine how the cars should deform. Finite element methods are used throughout the engineering industry for simulating how objects (be they bridges, aeroplanes or cars) will behave when subjected to different forces and, although it can be computationally very expensive, it does mean that the car model deforms based upon the actual direction and size of the impact. The damage model also supports localized particle emitters that trigger effects based on the materials you collide with and the force of the impact.