About a week ago someone made a video for Bad Company 2 showing a sniping comparison between the use of normal bullets versus the “Magnum” ammunition upgrade. Interestingly, they thought it showed no difference, while I came away with the opposite impression. This post is a horribly nit-picky comparison of shots in the video. Read more…
With the recent 2010 Halloween update to Minecraft, players are complaining about some of the changes to monster-spawning code which causes them to appear in otherwise-safe areas. After kicking some ideas around, I figured they might be worth a blog-post or two.
I’d like to present three ideas that should make the lighting-based monsters spawning system more viable. While it may seem to make players safer in their bases, it actually means that the game can place a greater emphasis on spawning lots of monsters because it reduces the chance of “weird” or “unfair” monster appearances.
The order in which cells are checked before spawning a creeper
Currently, monsters will spawn based on the brightness of the bottommost “floor” tiles. While this makes some sense from a technical standpoint, it neglects to consider how players prefer to light their buildings, and leads to cases where an area that seems properly lit can still be vulnerable.
To fix this: When deciding whether to spawn a monster, check any empty-space around the spot and make sure the surroundings (especially upwards) are either “solid” or else are also dark enough.
Blocks checked for light when obstructions are present
On the left you can see that for a 2×1 creeper (side-view) the spawning system checks each of the blocks in the order shown. If a block on the path is “solid”, the checking on that line stops. If any “open” block visited has a light-level that is too high, the creeper cannot spawn.
In conclusion, monsters can–as before–spawn in very small dark places. However, if the area is larger, some of the extra space is checked to make sure it is also dark-enough.
Some people may be familiar with this as “breadcrumbs” from AI terminology. Basically, the player leaves behind a “smell” in the world as they move around. This smell goes a small distance from them, and then hangs around areas they’ve been for a while before fading. A given area will have a smell that depends on how close the player was, and how long ago they were nearby.
Technical details: Each block (or perhaps each “floor” surface) has a special counter. Counters which are above zero will decrease with time (and are zeroed when the chunk is unloaded.) If the player is near a block, that block’s counter cannot be lower than an a certain amount based on how close the player is. This means that the “smell” of a block depends both on how long ago the player was nearby, and how close the player was to to that block before they moved away.
This basic idea provides two very useful possibilities in terms of both making players less-frustrated and also making monsters a slightly bigger challenge:
Most immediately-useful: Monsters can be prevented from spawning anywhere the player has very recently been, even if that place is poorly lit. This prevents annoying (and impossible) cases where you walk around a large room, and then a monster appears on the far side of it behind you as you are leaving through the only door.
It provides a way to make monsters smarter! OK, not very much, but smart enough to actually follow you around small corners. If they can’t directly reach you, they can try to follow the path you took by looking at gradients in the smells.
Currently, Minecraft’s lighting model is not additive. This means that (compared to the real world) adding more torches doesn’t always make certain areas any brighter than they were before. I’ve made a quick animation to illustrate what I mean by “non-additive”. In the real world, you would expect the area between both torches to become brighter, but it does not.
Click to see an animation showing how light is non-additive in Minecraft
This lighting model is partly responsible for the frustration people are having in deep areas of the world: They place torches in a way which seems correct based on real-world lighting, but it doesn’t really work. Every time you see someone make a 1×1 pillar with torches on all four sides, it’s an example of this mistaken belief. The way the minecraft world currently works, the ideal way to light things is to avoid grouping any torches together, yet players do this all the time because it’s what we “know” works.
Changing to an additive model (with an upper cap on brightness) would add visual realism and reduce the amount of frustration players will feel when trying to make areas safe.
Please see the project-page for download links.
This release is primarily small bug-fixes. Unfortunately,
screening out non-used static-prop skins is still not working until I
puzzle out more of the MDL format, sorry.
With the recent update to TF2, a new map, cp_manor_event, is in rotation. And with it, a new and oddball feature: NPC enemies.
The enemy is the Headless Horseless Horsemann, somtiems abbreviated “HHH”, reputed to be the ghost of Silas Mann from the series’ unfolding backstory. Here are some quick facts I learned from painful experience that I wish I had known several hours ago:
Not many updates recently, sorry.
Regarding minecraft, I’ve put it onto a USB stick so I can use it in my laptop as well, and I figured I’d share a quick launcher batch file that forces it to store all Minecraft-related data in the same spot as the launcher to create a “portable minecraft”. You still need to be able to log-in, though.
for %%F in (%0) do set dirname=%%~dpF set APPDATA=%dirname% minecraft.exe cmd minecraft.exe /C exit
You know how long-term deadlines somehow sneak up on you? Turns out the TF2 Art-pass contest is ending real soon, so I need to scramble a bit to get a newer version of PackBsp out.
Version 2.0.4 should mainly be bug-fixes and stability improvements: I don’t want to gamble too much on new features if people might be using it to submit final contest entries.
This week I’ve gotten very interested in an AI contest which apparently has some small support from Google. While fascinating , it has had the unfortunate effect of delaying the release of parts of Hl2Parse.
I don’t have anything submit-ready yet, but I hope to create a bot which can do some pretty intelligent play.
Edit #2: Oops! It seems a slightly-different but much-more-legible version of this document was presented as part of the classless update! I’ve left my original guesses and ***** marks in-place, but note that certain sections (ex. Silas Mann) are new.
I decided to take a stab at deciphering the tiny text of the Zephreniah Mann & Sons Co. Quarterly Concern, which was posted on the Engineer Update page. (May edit if new material is made legible.)
Read more…
Beta 3 is now available here.
Here’s a new Beta version, building on the previous one. Main changes/fixes:
