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Oily Textures In Low Settings

I just found a bug in beta 15 (and 14, and 13, and 12..etc.): if you use ATTR_shiny_rat or GLOBAL_specular with an intermediate value, e.g. between 0 and 1, you get an oily effect when HDR is off.

This is a bug in one of the shaders. We didn’t see it early because I have encouraged our art team to set the specular ratio to 1.0 and leave it there and use the normal map to modulate specularity. You should take that advice too! The GPU is really good at reading textures, and the CPU is not particularly good at interrupting the GPU to change what it’s doing, which is what ATTR_shiny_rat does.

Beta 16 will fix this; in the mean time, what you see in HDR mode (the top two FX settings) is correct, for the purpose of figuring out if your art looks good.

Posted in Development, Modeling by | 2 Comments

Beta 15: A Quick Fix

Just  a quick note: beta 15 is up and fixes a few key bugs:

  • No more Plane-Maker crashes opening files.
  • ACF files aren’t locked while the sim is running.
  • Cessna takeoff should be a lot better.

I’ve heard a lot of chatter about FPS problems with the new clouds. If you are having FPS problems with the clouds, here are a few key things we need for a bug reports:

  • Include a log.txt. We get enough bug reports that if you ignore the “always include a log.txt” note in the bug report, your bug report will go to the back of the line. Everything that we tend to ask users that can be gathered automatically is in the log.txt: your CPU info, GPU info, driver, version of X-Plane, add-ons installed, scenery…there’s a reason why we want it!
  • Be sure to note your monitor configuration (how many, how big, what you’re doing with them).
  • Include a full res screenshot of the clouds where FPS are bad, preferably with the FPS counter showing. Please don’t use JPEG or crop it – I need to see what the rendering engine is doing.
  • Try setting the weather to clear – does that improve FPS?  Try changing your window size. Does that improve FPS?  These differentials are useful.
  • For a given view where FPS are awful, does regenerating the weather (bind a command key) change things or is it always bad?
  • If FPS are always bad, send us a .sit file where, in the cockpit of an aircraft that we ship with the sim, framerate is really bad.  We can load the .sit file, regenerate the weather a few times, and see what’s up.
  • Update: one more thing – if you are using a third party aircraft, does changing to one of ours fix the issue? Does changing the shape of the 3-d cockpit (which blocks out clouds) fix the issue?
Posted in Development by | 75 Comments

X-Plane 11.0 Beta 14 and the State of Various SDKs

X-Plane 11.0 public beta 14 is out. This one is a bit of a two-steps-forward, two-steps-back. Some notes:

  • You won’t need a ton of thrust to start moving anymore – Austin was able to remove that hack from the tire model based on some new ideas for modeling low speed tire physics that get around a years-old problem.
  • The Cessna apparently wanders around the runway like a drunken moose.
  • Max’s new cloud art is in. Under some views and conditions, you may get significantly better performance.
  • Under other views, they may kill your GPU. I’m looking into this.

Most importantly, I broke Plane-Maker, so public beta 15 will be out in 24 hours, and I’m going  to sit in the corner and have a time-out for a few minutes. If we have a fix for the Cessna in that time frame, we’ll ship both, otherwise I’ll get a patch out to fix Plane-Maker and we’ll get to tires soon.

The State of Various SDKs

SDK stands for software development kit, but the term is now used more generally for the various interfaces, tools, and file format standards to make add-ons of any kind for X-Plane, even if there is no program (software) involved. I’ve been getting a lot of questions about what’s safe to start developing on top of, and what’s going to be ready for third parties. Here’s a quick update on the status of some of the V11 SDKs.

FMOD + Sound

FMOD-based sound is one of the biggest new features for third party developers in X-Plane 11. Here’s the status:

  • FMOD support is feature complete in public beta 14. Therefore we expect to have X-Plane sound “third party ready” by the time we go final with 11.0.
  • There’s a lot to document about FMOD. I have already started the beginnings of full documentation, but it will take time to get it on paper. I’m hoping to have draft FMOD docs that you can use shortly after we go final.
  • There’s a lot of details to get right in making an FMOD-enhanced aircraft; please do not ship an FMOD-enhanced aircraft before the docs come out – there’s a very high chance of doing something wrong if you’re just trying to guess how the system works from our Cessna project.*

When we ship, we will have bare bones tools for working with FMOD, but we will publish everything we had when we did the Cessna, and this setup is adequate for creating production aircraft. Fortunately, most of the work is done in FMOD Studio, a rich, full featured sound editing environment. It’s great to use.

The ‘thin’ side is X-Plane support: the sound attachment file (.snd) that links FMOD events to your aircraft has to be built in a text editor. We also have some graphical debugging and it is possible to attach a live mixer to X-Plane while you fly.  All of this will be covered in the docs.

In the long term, we’d like to make the sound attachment system visual and have it run inside X-Plane while you fly.

What you can do now: learn how to use FMOD!  Download the FMOD studio editor (it’s a free download) and start working with its sound design tools.

Graphics – Aircraft, Scenery and Modeling

I still have a list of graphic artifacts, but I think the overall operation of the new lighting system is as it will be for shipping 11.0. You can start using the new material model now; until the exporters have direct support, you can always add the NORMAL_METALNESS directive by a text editor or add it to a PNG comment.

Probably the biggest weakness of the new lighting model right now is the lack of detailed control over the interior of aircraft; I expect we’ll have new techniques to cope with this in future updates, but they won’t be mandatory aircraft changes. Unfortunately I don’t have good work-arounds right now for aircraft where the interior lighting is unacceptably weird.

What you can do now: tune the brightness and alpha levels of translucent textures – they need to be adjusted for X-Plane 11’s linear blending. Fix any panel problems introduced

Aircraft Physics and Systems

One of our biggest pushes right now is to try to get to “done” on the aircraft physics and systems code. The engines should be done – we don’t have known open bugs. The tire modeling is still problematic as of public beta 14; Austin has a fix for the bad behavior of the Cessna in beta 15.

What you can do now: test your aircraft’s physics model with X-Plane 11. If you have a fleet of aircraft, pick one particular aircraft and carefully update it for X-Plane 11. If you find out that there’s a physics problem after we go final, we’re going to have a lot less flexibility to fix things.

We run the physics engine on our own fleet (and we don’t use plugins to modify the physics) but that’s a limited set of aircraft. If you have good data about how your aircraft doesn’t work right with our flight model and good input data in Plane-Maker, we’d like to hear about it.

Weapons

The weapons SDK is the one area where we have moved temporarily backward from X-Plane 10. X-Plane 11 features a new unified weapons system that takes technology from both X-Plane 10 desktop (for physics) and X-Plane 10 mobile (for multiplayer simulation). Unfortunately, we haven’t had time to create an appropriate dataref interface to these weapons.

Getting the interface to weapons finished is on our short list for after 11.0 ships; I do expect that the list of datarefs may be different for 11.xx than it was for X-Plane 10. The new system has new capabilities that make the old “fixed index of weapons” model not a great fit.

Unfortunately, this means that if your add-on depends on plugin-controlled weapons, you’re stuck in a holding pattern until we can post a new interface that we can maintain.

Plugins

As of public beta 14, plugins should just work – we’ve closed the remaining plugin API and major dataref bugs. There are a few areas of fine print:

  1. You can’t use drawing callbacks in the map in X-Plane 11 – the totally rewritten map doesn’t use the same coordinate systems, so there is no way we can make old code work.
  2. Some datarefs and commands are not available in X-Plane 11. This is a normal part of the evolution of the sim.
  3. Multi-monitor support has a pile of bugs when you put X-Plane’s menu bar on the second monitor. If your plugin works normally except in this condition, it’s probably an internal X-Plane bug you’re seeing.

Note that to control toe brakes in X-Plane 11, you now need to set an override. Once you do, you completely own the toe brakes – you can look at the raw joystick input datarefs if you want to write a plugin that “processes” toe brake inputs to create some kind of effect.

What You Can Do: Check the command and dataref lists that are in Resources/plugins. If you need a command or dataref that has been dropped (and is not weapons related), contact us to discuss your use case and we’ll figure out what to do. If you are still seeing plugin bugs, file them now!

What we will not have done for 11.0 is entirely new plugin functionality to expose new X-Plane 11 specific features. We will need to do a major API revision to allow plugins to undock windows (like our GPS and map does), to expose some of the new FMS capabilities (expect a limited API) and to restore map customization functionality.

Particle FX

The particle system SDK is kind of done, mostly. We use it in the shipping mobile product, and the editor is available in the desktop product now. I still have two features left to do that Austin considers “must-have”; I expect to get them in shortly after we go final, at which point we can start providing documentation. (One of those features is the ability to control aspects of the particle system from multiple datarefs – that will change the UI enough that it’s not worth writing docs now and then changing them.)

My suggestion is to stand by on this – it won’t take that long to get the system to a “tinker with it” stage.

 

* I am quite impressed with how far some people have gotten without docs! But shipping an add-on that “seems” to work but violates the SDK rules makes a compatibility mess later.

Posted in Development, News by | 42 Comments

In the Long Term, Plugins Shouldn’t Draw In 3-D Directly

Plugins can use OpenGL to draw directly inside X-Plane; this capability is almost fifteen years old and goes back to X-Plane 6. Plugin drawing typically falls into four categories:

  1. Drawing user interface (floating windows, HUD-like UI, map details, etc.).
  2. Drawing custom panel instruments (particularly 2-d glass displays).
  3. Drawing effects in 3-d (custom smoke or fire, or maybe diagram marks showing lift).
  4. Drawing solid stuff in 3-d (e.g. pushback trucks, parts of the airplane, etc.).

These first two use cases work pretty well; the third case works barely, and the last one is a bit of a train wreck.

Problems With Plugin Drawing

OpenGL an 3-d hardware was very different when Sandy and I created the original plugin SDK 1.0. Hardware had a fixed function pipeline built into the GPU itself, and your computer had one CPU core, so the issues I’m going to describe weren’t a problem back then. Here are some problems with plugin drawing:

  1. Increasing overhead just to draw. It used to be that we could just send a message to the plugin system at “good times” and let drawing happen. X-Plane now has to do a bunch of work to prepare OpenGL for plugin use; this synchronization work slows down X-Plane, and it’s getting worse as X-Plane’s internal design diverges from the canonical OpenGL 1.5 pipeline. (Example: we have to copy our matrices into the fixed function pipeline matrices before we call you, then copy them back if you call us with a drawing routine. Slow!)
  2. Plugins don’t have access to the fastest drawing paths. The less our drawing looks like OpenGL 1.5, the less efficient plugins are in comparison to X-Plane. This is getting worse over time too. (For example: if we want to render two VR eyes at once, we have to call your plugin twice, once for each one.)
  3. Plugins don’t have access to our lighting environment or G-Buffer formats, and thus can’t easily draw in a way that integrates with our 3-d world. This is getting worse as our rendering engine becomes more complicated.

So…this is not fantastic. The first two use cases (UI and panel) aren’t that badly affected because the two of them require only 2 or 3 call-outs to plugins, drawing in a very simple manner.  The second two (3-d use cases) are quite problematic.

These costs are going to get worse when X-Plane moves to Metal and Vulkan drives; the cost of syncing over to OpenGL will be higher, plugins won’t even be drawing on the fastest APIs, and we may have to do some expensive texture synchronization.

Fixing The Problem

My goal isn’t to completely eliminate the costs of plugin drawing; rather just to minimize the costs by providing better alternatives for common tasks.

So in the long term, my plan is to add something to the SDK that we should have had for a while: the ability to create persistent object and effect systems in the X-Plane world.

Right now if you want to draw an object, you call XPLMDrawObjects – hopefully you’re doing this from just the right callbacks, but if you get this wrong, I forgive you; the rules for how to do this correctly in the v10 and v11 renderers are insanely complex, because the plugin API was invented fifteen years ago.

In the future, you will be able to simply create an object and X-Plane will draw it at all the right times, for any rendering mode, handling all of the special cases for HDR, shadows, reflections, you name it. You’ll just need to tell us when it moves. The same idea can be applied to particle systems for effects.

The one open issue with this scheme is how animation will work. Currently animations is handled by reading datarefs – if you want to animate multiple instances from a plugin, you have to figure out (inside your dataref handler!) which instance is being drawn and return the right animation values.

Not only is this a complicated mess, but it’s also slow; it requires us to call your dataref callback many times from inside the drawing loop, slowing everything down.

What I’d like to have in the future is some kind of ‘animation block’ where:

  1. Your plugin queries the object to find out which animation values it needs.
  2. Each time you update a particular instance of that object, you provide a packed block of the values of all of those animations.
  3. We use the block directly and never have to call datarefs.

This technique isn’t just faster, it also is easier to make multi-core and will play nicely when we can instance animation in the future.

The time frame for this is “during the v11 run hopefully” – that is, a new object API is not going to be in 11.0, and I can’t guarantee when it will be. I expect to support the old way (XPLMDrawObject and drawing hooks) at least through the entire v11 run, if not longer; our expected failure mode is ‘if you do it the old way, the sim might be really slow’. The new APIs will be designed to be completely friendly with multi-monitor, VR, Vulcan, and multicore.

 

Posted in Development, Plugins by | 49 Comments

Beta 12 And Engine Chaos

X-Plane 11.00 public beta 12 is out. A few notes on the engines:

  1. Jet engine thrust at low N1 should be fixed; you should no longer have to kill the ground crew to taxi around the ramp. If you find weird jet engine N1 behavior, please report a bug ASAP!
  2. Reciprocating props will need to have their idles adjusted, perhaps a bit higher, particularly if your idle adjustment is < 1.0 in Plane-Maker.  We had to bump up our Cessna, which was set to about 0.8 and was stalling if not given a little extra throttle.
  3. The engine start code has some kind of bug that is stopping engines from starting.

 

If you’re hitting this last case, please file a bug and include the aircraft that won’t start.

From what I can tell, the beta 11 code is actually correct for some airliners, but is wrong for others. I’ll have more details later and I suspect we’ll have a beta 13 that addresses this by Tuesday.

Posted in Aircraft & Modeling, Development by | 53 Comments

Maybe X-Plane Is a First Person Shooter

In a previous post I noted that we weren’t attempting dynamic ambient occlusion inside the 3-d cockpit, due to problems of quality, availability, and because it wasn’t really better than what authors do now: prepare the AO offline using a high quality render in their 3-d modeler.

I’ve been thinking about this a while: while I like to get up on my soap box and shout that X-Plane is not like a first person shooter any time we get compared to a AAA console title, there is one case where X-Plane kind of is like one: inside the user’s aircraft.

First person shooters often specialize in rendering highly controlled, closed, constrained, claustrophobic environments in ludicrous detail at very high framerate. To achieve this, they take advantage of optimizations specific to those closed, controlled environments: lots of things are pre-computed, pre-baked, and pre-calculated.

X-Plane’s scenery engine mostly focuses on throughput; once you climb through 500 feet you can see everything at an airport, so we just try to draw really fast. But the inside of the aircraft is different. Baking at least part of the interior lighting is pretty much a standard practice. We provide object-kill datarefs to let authors script their own culling algorithms to squeeze framerate out of a confined space.* We define sound spaces within the aircraft that can change how sound effects are filtered.** We let you mark which parts of your aircraft receive interior and exterior light. (This feature is called “light groups” in a regular 3-d game engine and it’s very common, particularly in older forward-rendering engines.)

All of this stuff is a lot more like a game with a 3-d level editor than the rest of X-Plane. Techniques that focus on interior spaces are a good fit inside an airliner.

Better Baking: one of the features planned for our next-generation modeling format is to allow multiple UV maps for a given model***. We can then add an ambient-occlusion texture to an object’s shader and you can bake your aircraft interiors at a much lower resolution than you albedo textures.

For example, you could use a high-res repeating texture to draw the seats inside the aircraft, copy-paste the seat down the cabin, and then unwrap a second UV map that covers the entire cabin uniquely.  Bake to this second UV map, down-size the texture to super low res (it’s ambient occlusion, “soft” is okay) and you’ll get high-res detail with unique correct lighting queues all over the aircraft. This is a standard work-flow for 3-d game engines and seems like a good fit for aircraft interior.

Edit in the Sim: we can take another clue from game engines and provide editing of graphical aircraft information inside X-Plane. We already do this for the particle system – the editor is built into the sim itself.**** The advantage of editing in the sim is that you can see your work exactly how it will look in real time.

 

* Engines that focus on interior spaces often have techniques like portal culling built-in and tools to precompute the information for this culling automatically.

** This is part of the new FMOD SDK – we will get this documented around or shortly after 11.0 goes final.

*** I realize this isn’t very “next-gen” in the world of rendering engines – it’s just the next major modeling revision for X-Plane.

**** The particle system isn’t documented because it isn’t quite finished yet. It’s shipping in mobile, enabled on desktop, but it is not running the default effects right now.

Posted in Aircraft & Modeling, Development, Modeling by | 21 Comments

We’re hiring!

We’re looking to add two developers—one junior, one senior—to the Laminar Research team this spring.

As a member of our team, you would:

  • Work on stuff that matters. Real pilots fly safer because of training in X-Plane, and real aerospace organizations (like Boeing, Cessna, and NASA, to name just a few) prototype aircraft in X-Plane before they build them in the real world.
  • Work on a product that millions of people will see. You’ll get feedback from users, and that feedback will drive future development.
  • Have tremendous input on the direction of the product. Because X-Plane is an exceedingly small team, every team member has a lot of say about what we work on and how we make the simulator better for our users.
  • Set your own schedule. As far as we’re concerned, if you’re shipping features and fixing bugs, it’s your business when you do so.
  • Work remote. No commute, no cubicles, nothing to impede you from doing great work. (But the rest of the team is just a Skype call away!)
  • Work on a variety of technologies and products. At various points, you might work on X-Plane, Plane Maker, WED, the X-Plane installer, the Scenery Gateway web app, or even the X-Plane.com web site.

Qualifications

A qualified junior candidate will:

  • Have a computer science degree.
  • Be a quick learner. We expect most of what you need to know (beyond computer science fundamentals) to be learned on the job.
  • Have the self-discipline to work from home and set your own schedule. (It’s not for everyone.)

In additions to the above, a qualified senior candidate will:

  • Have experience shipping major features in production applications with minimal oversight.
  • Have specific experience relevant to X-Plane. There’s no exhaustive list of skills we could use, but some possible examples include:
    • Real-time graphics
    • Real-time C++ development
    • Mobile development
    • Game development
    • GIS data processing
    • Networking
    • The X-Plane plugin system

How to Apply

Send an email introduction to me that includes:

  • Which position you want to apply for
  • A brief overview of a project (or projects) you’ve enjoyed working on
  • Discussion of projects you have not enjoyed working on

The introduction is really just a means for me to get a handle on who you are as a developer, so do not stress over it!

My email is my first name at X-Plane.com. Please do not attempt to apply in comments!

(Not sure if this is a good fit for you? Email me anyway and we can talk. 🙂 )

Posted in Hiring by | 16 Comments

Screen Space Ambient Occlusion Only Affects Exterior Stuff

This has been a point of confusion for third party developers, particularly ones who were in the private beta (and saw versions of the sim that…cough cough…didn’t work right).

Screen space ambient occlusion (SSAO)*, when enabled by the highest rendering settings, only affects exterior objects. This means scenery and aircraft-attached objects marked “exterior” for lighting.

I tried SSAO in the cockpit interior, and it had a few problems:

  • The scale for occlusion in the interior and exterior of the cockpits is really different – I couldn’t find one size for the effect that fit all cases.**
  • When I went to apply the effect to our fleet, I found that virtually all of our aircraft already had occlusion baked into the cockpit by the artists. The dynamic AO thus provided almost no value and made the cockpit even darker than it already was.***
  • SSAO only works at the highest rendering settings (and requires HDR to function at all), so if artists remove their baked AO, they’re taking a pretty big visual loss in a bunch of settings.

So in net, it just wasn’t worth going to dynamic AO in the cockpit. Our AO isn’t as high quality as what you can bake in a 3-d program (given a few days of rendering time), and it’s not always available.

The real win for SSAO is outside the aircraft, e.g. to cast AO around the wheels of the aircraft on the ground. That’s an effect that you can’t bake, and it helps a lot with lego brick scenery too.

* Nerd note: I’m pretty sure that what we do is actually HBAO

** We could, in theory, apply the effect twice with stenciling at two different scales.

*** The cockpit tends to be dark both due to errors in our approximation for indirect light (because most of the cockpit is in shadow, and thus only lit by indirect light) but also because cockpits are actually pretty dark compared to the great outdoors. But that’s another post.

Posted in Development, Modeling by | 32 Comments

Usage Data for X-Plane 10 & 11

You might have noticed we’ve been working our tails off to make X-Plane 11 an amazing sim, with tons of new features, and during that time we didn’t have the resources to do anything further with our proposal to publish X-Plane usage data. The good news about our delay is: we now have usage data for both X-Plane 10 and X-Plane 11.

Since one of us (ahem) remembered we had promised to provide this at intervals, here’s the latest data update. It’s still not particularly pretty, but we have a handful of easy-to-digest charts, plus the raw data at the bottom of the post for those that are interested.

Items of note

All data in these charts are for users of the full version only—we’ve filtered out demo users.

If an aircraft’s name, studio, or number of engine fields in Plane Maker are changed at any point, the aircraft will show up in the data as two different entries.

Aircraft

Aircraft categories by popularity

X-Plane 10 popular aircraft categories

X-Plane 11 popular aircraft categories

Hardware

Users with at least this much RAM

Flight controls in X-Plane 10 & 11

Operating Systems running X-Plane 11

GPU Manufacturers

Raw Data

There are four files here: hardware data and aircraft data, for X-Plane 10 & 11. Each contains all the information we have since September 2015, for paying customers only (no demo users).

Posted in Uncategorized, X-Plane Usage Data by | 37 Comments