What's New in Rust's "Friday Devblog 18" Update

Friday Devblog 18 came at the end of July 2014, right after the previous week's enormous sprint. Garry expected to spend it entirely on fixing and refactoring and was surprised by how much still got done - most notably an event system to drive airdrops, a spectator mode that made animation bugs far easier to catch, and a properly material-driven impact effect system.

Spectator mode

Some bugs were only really diagnosable by watching other players, so spectator mode was added. It works much like Counter-Strike's, and proved insanely useful for development - particularly for spotting odd animation bugs that are hard to study in detail while also trying not to get killed.

At this stage anyone could enter it by typing spectate in the console, with respawn to return, and jump and duck to cycle between players. Garry expected it would end up admin-only, with the ability to spectate other entities like animals added later.

The event system

A new event system went in - the machinery that creates events like the airdrop. Airdrops worked well in the existing version of Rust and the team wanted more events like them.

The design goal is explicitly modelled on the AI director in Left 4 Dead: eventually it should be able to observe that a lot of players are hungry and launch an event relevant to that. At this stage it was much simpler, throwing out a random event roughly once per game-day. The cargo plane is back as part of this, though it doesn't drop its load yet - it does have little blinking red lights that illuminate the landscape below at night.

Impact effects

Petur got a tool to test the impact particles he was making, and those effects are now in game. Every collidable object in the world has a physics material assigned - wood, concrete, metal, flesh - and the effect is chosen from that. Two cases needed special handling.

The terrain uses splatmaps and multiple textures, so it has to be queried to find out which texture was hit - sand, grass, mud, rock, snow - and the particle chosen accordingly. That matters most for footsteps, where different sounds and effects per surface material make a real difference.

The second case is skinned meshes like players and animals. A shot player should almost always return Flesh, but the system was built so each bone and each clothing piece can return a different physics material. So if a helmet is added later, shooting a player in the helmet returns Metal and produces a spark.

Tools and documentation

A clothes tool was built to help artists implement and visualise their clothing, addressing something seriously lacking in the old version of Rust - artists would build models but never see them in game until they were implemented and usually already live. They need to see models and textures under the real game's lighting, next to other in-game assets for scale. Garry's note on tool-building is that he both hates it, because only a handful of people use them, and loves it, because it exposes people to a lot of good work; this one apparently turned into GMod at some point.

Documentation was also written for the artists and programmers, and published publicly on the grounds that there was no reason to hide it - even if it's useless to anyone without the source code.

Smaller changes

• You can now see bullets and arrows fired by other players, so you can actually tell where you're being shot from.
• Bill's new rocks went into the maps, with some tweaking still to do.
• The snowy biome is in, though underwhelming at this stage - it needs per-biome weather cycles, LUT values, detail models and ambient dressing. Right now it's snow and snowy trees.
• Dragging an item onto another item in your inventory now switches their places.
• Bill and Petur made a new background scene for the menu.
• Invert Y is available: open the console with F1 and type input.flipy 1.

Art progress

Goosey LODed all the animals, which brings both higher performance and the ability to use the skinned mesh collision approach from the previous devblog, and nearly finished animating the boar. Alex worked on torch animations. Dan finished the hammer and LODed all the tools, marking them ready. Scott spent the week prototyping how buildings fit together - the team wanted to get the structure system right rather than rushing it, and Garry noted it's the kind of problem that gets harder the more you think about it.

Closing

The open question at the end of the week was whether to make the Rust Experimental server binary available to everyone. Garry couldn't think of a reason not to, but was wary because once it's out, it's out - and while he could technically render the server incompatible, hundreds of people would be renting servers by then, and breaking them would also break their customers, who are Facepunch's customers too. The decision was being held until they were certain there was no good reason against it.