https:\/\/zippy.gfycat.com\/ThirdWealthyHyena.webm<\/a><\/video><\/div>\n

It took a day of prototyping, building, and debugging to get this one interaction to work, and it\u2019s still a bit unreliable. It looks nice and smooth, but behind the scenes we\u2019re creating, configuring, and destroying multiple joints in those few seconds. Those joints are built off of the behemoth that is ConfigurableJoint. Anyone who says they understand all of its parameters and their interactions is lying to you:<\/p>\n

$\"26_iq39vaseyg\"$ <\/p>\n

They\u2019re prone to weird bugs that are essentially undebuggable<\/h3>\n
PhysX is remarkably robust and accurate; it truly is shocking just how much of the time it looks right.<\/p>\n
Despite this, any physics-based game is going to encounter its fair share of weird bugs.<\/p>\n
\n
Maybe two objects pass right through each other because they\u2019re going too fast.<\/li>\n
Perhaps thin objects don\u2019t lie flush with other objects and start jiggling.<\/li>\n
Sometimes your fixed joints start to drift apart from each other because you\u2019ve chained too many together.<\/li>\n<\/ul>\n
If you\u2019re lucky, the bug will happen at a time that doesn\u2019t affect gameplay. However, there\u2019s always the danger that your critical-path item will be sent flying by a weird interaction. These problems are significantly worse because the physics system is largely opaque to debugging without building something like this<\/a><\/span>. The physics engine is a complex system<\/a><\/span>\u00a0that spins off unpredictable issues. That\u2019s a tough foundation to build a game on.<\/p>\n
Games require all sorts of weird, fundamentally wrong interactions<\/h3>\n
VR systems can\u2019t yet impart forces back on the player. This is obvious, but causes problems when interacting with a physical simulation.\u00a0This limitation leads to lots of little questions whose answers interact in messy, unphysical ways:<\/p>\n
\n
Should I be able to put my hands through objects? If not, what happens when my in-game hands stop tracking my real-life hands?<\/li>\n
What happens if I grab an object with both hands and pull them apart?<\/li>\n
What happens if I grab an object that\u2019s bolted down and pull on it? Should my hand separate from the object?<\/li>\n
How do I represent heaviness if all objects can be moved in the same way by my virtual hands?<\/li>\n
What happens when objects accidentally clip out of bounds? Should they respawn?<\/li>\n
How do I represent fine motor control without finger tracking?<\/li>\n
How do I pick up objects? Which button is it? Should it \u201csnap\u201d to my hand?<\/li>\n<\/ul>\n
Any answer to the above questions is a non-physical workaround, and any combination of these answers is gonna have some weird, unintended consequence that feels wrong. There isn\u2019t yet a set of conventional answers to the above questions, either, which means every game has to overtutorialize some of its interactions.<\/p>\n
In Spearmint 1, I ran up against these issues all the time. Making small fixes for every interaction was a frustrating time-sink. Some examples I ran into:<\/p>\n
\n
When pushing the wire against the battery, the ends of the wire would jump around and vibrate a lot because they had become separated from the physical hand holding them.<\/li>\n
Picking up the desired sheet from a stack of paper was a challenge for players, and picking up the wrong one sent the rest of the papers flying.<\/li>\n
When the keys had been inserted into the ignition, the keys would start to turn automatically as if the player had been starting the machine. This was because of an obscure orientation error in setting up the joints.<\/li>\n
At one point, the handles on the safe wheel would come off as you tried to turn the wheel. This was caused by setting up multiple chained fixed joints (the handles were fixed to the wheel, the wheel was fixed to the door, the door was fixed to the body). The solution was to lower the mass of the handles, which makes no physical sense but solved the issue.<\/li>\n<\/ul>\n
For my next project, I\u2019m leaning towards something less physical and more ethereal. If force\/interaction is only one-way in the current VR systems, then perhaps games should reflect those limitations.<\/p>\n
Interesting Failure #3: Text sucks in first-gen VR<\/h2>\n
This is a quick one. First-gen VR headsets aren\u2019t hi-res enough to build games around text. Text can easily be blurry if the player has the wrong fit on their head and even then it has to be unreasonably large (think 48pt documents) to be readable. This doesn\u2019t mean your game should have no text; it just means that you may not want to make it important to the gameplay.<\/p>\n
Interesting Failure #4: Took too long to get playable<\/h2>\n
I should have known better, but I only had a fully playable version of the game 2 weeks before release. Getting playable early gives me more time to understand what parts of the game work and what parts need to be cut. It also motivates me more if I\u2019m able to actually show people what I\u2019m working on. So what went wrong?<\/p>\n
The escape game genre doesn\u2019t get to a playable state very early. The puzzles and interactions in escape games often rely on the actual asset being present. If your key doesn\u2019t look like a key, people aren\u2019t going to know what to do with it. A better approach is still a bit of a mystery for me — what does an early, prototype version of this escape game really look like? What was the real bare minimum I needed?<\/p>\n
Parting Words<\/h2>\n
While I\u2019m not head over heels about the final project, I\u2019m thrilled to have something finished and uploaded. In the name of complete transparency, I\u2019m also uploading all of my design documents <\/a><\/span>and sketches for the game. If you\u2019ve ever wanted to look into the head of another developer, here\u2019s your chance. I\u2019m also going to work on getting Spearmint 1 open sourced — there\u2019s no reason for me to hide the code. I just have to work through the licensing issues around the assets.<\/p>\n
After that, Spearmint 2 starts development soon. Hopefully I\u2019ll scope a little better and pop it out in something like 30 days. Seeya then!<\/p>\n","protected":false},"excerpt":{"rendered":"
WARNING: IF YOU HAVEN\u2019T PLAYED SPEARMINT 1 YET, GO DOWNLOAD IT AND TRY IT\u00a0OUT. IT\u2019S A QUICK GAME; I\u2019LL WAIT HERE FOR YOU. Spearmint 1 started as an experiment in making and releasing a game in 30 days. Instead, it took about 70 days. I\u2019ll be posting later about the process of making the game […]<\/p>\n","protected":false},"author":1,"featured_media":25,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-26","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/posts\/26","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spearmints.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=26"}],"version-history":[{"count":0,"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/posts\/26\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spearmints.co\/index.php?rest_route=\/wp\/v2\/media\/25"}],"wp:attachment":[{"href":"https:\/\/spearmints.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=26"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spearmints.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=26"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spearmints.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=26"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

<\/h3>\n

More details<\/h3>\nLights look for an object that implements IWatchableBool. Objects that implement IWatchableBool report one boolean value, which was generally some version of \u201cam I activated?\u201d<\/p>\n

They\u2019re prone to weird bugs that are essentially undebuggable<\/h3>\nPhysX is remarkably robust and accurate; it truly is shocking just how much of the time it looks right.<\/p>\nDespite this, any physics-based game is going to encounter its fair share of weird bugs.<\/p>\n