Hi fellow wiki editors!

To help newly registered users get more familiar with the wiki (and maybe older users too) there is now a {{Welcome to the wiki}} template. Have a look at it and feel free to add it to new users discussion pages (and perhaps your own).

I have tried to keep the template short, but meaningful. /Johan G

Difference between revisions of "Compositor"

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http://www.zaretto.com/sites/zaretto.com/files/compositor-effects-registry.pdf <ref>https://sourceforge.net/p/flightgear/mailman/message/36606242/</ref>
 
http://www.zaretto.com/sites/zaretto.com/files/compositor-effects-registry.pdf <ref>https://sourceforge.net/p/flightgear/mailman/message/36606242/</ref>
  
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=== Canvas support ===
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So far, we were focused on implementing camera views in Canvas. We also keep in mind that this might be an important groundwork for what might be RTT support for effects/shaders. For that we obviously need a link between Canvas and Effects. It's kind of a good thing that both systems are completely separated and don't know of each other, we are given more freedom when it comes to joining them. This link is kind of delicate and has to be well planned out. For example Hooray (and also Thorsten, but I'm not too sure) suggested per-element effects. It'd be kind of useful to have that, but would that give us the flexibility we need? Shaders can receive many input textures and modern shaders support MRT (Multiple Render Targets) too. It makes sense to come up with some kind of well defined link between Canvas and Effects that allows for inputting/outputting canvases via effects. This would allow the same things that per-element effects would allow but with more flexibility and less overlapping functionality. <ref>https://forum.flightgear.org/viewtopic.php?f=47&t=32846&#p318059</ref>
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What we have now, works similarly to how Rembrandt does its buffers. There is a new texture type called "canvas" that allows shaders to access any canvas texture via a texture unit, just like you'd access a normal texture from the hard drive. This removes (most) limitations of addPlacement, which can only substitute the "base" texture (unit 0). The posibilities are endless, it just needs some care and work. At the moment we could have shadow mapping outside Rembrandt just by creating a new view placed at the Sun and make it render the depth buffer to a canvas. Then every ALS shader could access this canvas and do the shadow comparison thingy. Planar reflections in the water should be kind of trivial as well, it'd just require the model-view matrix to be multiplied by a reflection matrix and the water shader could just paste the result over the water surface (with some more fancy calculations to make it pretty of course).<ref>https://forum.flightgear.org/viewtopic.php?f=47&t=32846&hilit=canvas+view+element+offscreen#p318662</ref>
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Actually, every ALS shader could choose to access this canvas - so one can run the more detailed opacity map technique in cockpit and shadow mapping outside for instance.<ref>https://forum.flightgear.org/viewtopic.php?f=47&t=32846&hilit=canvas+view+element+offscreen#p318693</ref>
  
 
=== Availability ===
 
=== Availability ===

Revision as of 05:33, 30 November 2019

This article describes content/features that may not yet be available in the latest stable version of FlightGear (2018.3).
You may need to install some extra components, use the latest development (Git) version or even rebuild FlightGear from source, possibly from a custom topic branch using special build settings: -DENABLE_COMPOSITOR=ON.

This feature is scheduled for FlightGear 2019.2. 100}% completed

If you'd like to learn more about getting your own ideas into FlightGear, check out Implementing new features for FlightGear.


Compositor Framework
ALS Compositor pipeline.jpg
Started in 01/2018 (Available since FlightGear 2019.2)
Description Dynamic rendering pipeline configured via the property tree and XML
Contributor(s) Fernando García Liñán
Status Stable
Folders

The Compositor aims to bring multi-pass rendering to FlightGear. It encapsulates a rendering pipeline and exposes its parameters to a Property Tree interface. At startup, FlightGear reads the pipeline definition file for each physical viewport defined on the CameraGroup settings. If no Compositor file is specified for a physical camera, the one given by the --compositor= startup command will be used. If such startup option is not used either, FlightGear will look for a valid Compositor file in $FG_ROOT/Compositor/default.xml

The Compositor introduces a new dedicated fgdata directory for new/custom rendering pipelines: fgdata/Compositor.

Background

First discussed in 03/2012 during the early Rembrandt days, Zan (Lauri Peltonen) came up with a set of patches demonstrating how to create an XML-configurable rendering pipeline.

Back then, this work was considered to look pretty promising [1] and at the time plans were discussed to unify this with the ongoing Rembrandt implementation (no longer maintained).

Adopting Zan's approach would have meant that efforts like Rembrandt (deferred rendering) could have been implemented without requiring C++ space modifications, i.e. purely in Base package space.

Rembrandt's developer (FredB) suggested to extend the format to avoid duplicating the stages when you have more than one viewport, i.e. specifying a pipeline as a template, with conditions like in effects, and have the current camera layout refer the pipeline that would be duplicated, resized and positioned for each declared viewport [2]

Zan's original patches can still be found in his newcameras branches which allow the user to define the rendering pipeline in preferences.xml: FlightGear, SimGear.

At that point, it didn't have everything Rembrandt's pipeline needs, but most likely could be easily enhanced to support those things.

Basically, the original version added support for multiple camera passes, texture targets, texture formats, passing textures from one pass to another etc, while preserving the standard rendering line if user wants that. [3]

Since the early days of Zan's groundwork, providing the (hooks) infrastructure to enable base package developers to prototype, test and develop distinct rendering pipelines without requiring C++ space modifications has been a long-standing idea, especially after the Canvas system became available in early 2012, which demonstrated how RTT-rendering buffers (FBOs) could be set up, created and manipulated procedurally (i.e. at run-time) using XML, the property tree and Nasal scripting. [4]

The new Compositor is an improved re-implementation of Zan's original work using not just XML, but also properties and a handful of Canvas concepts.

News / Changelog

Developer Discussion

Note  This is a rough summary of the main topics discussed among core developers on the FlightGear Devel mailing list.

Integration

The Compositor is disabled by default at compilation time in FlightGear (not SimGear). Both Rembrandt and the forward pipeline are still available if this flag is disabled.[5]

The Compositor is a standalone part of SimGear, the problem is the interfacing with FlightGear (CameraGroup and the FGRenderer). It's hard to have two simultaneous renderers when many other parts of the sim rely on it. You always end up with a lot of 'if' branching, as it happended with Rembrandt.[6]

Compatibility

it is worth remembering that at the moment compositor is identical to the default pipeline and thus there will be no advantage for flying - it is currently there so we can develop it further[7]

The Compositor is designed to be compatible with everything in FlightGear, except of course Rembrandt and the classic forward pipeline. It makes use of Effects for everything shader related and works seamlessly with multiple monitors/windows defined in the CameraGroup. There are also plans to support Canvas.

FGData structure

The current approach seems fine - i.e. having a Compositor folder within fgdata to provide some isolation of the new components.

My approach would likely be to create a Compositor/Shaders folder for shaders rather than using the existing fgdata/Shaders folder. Once things mature, I'd revisit this to determine a long-term folder structure.[8]

Richard has proposed a similar file structure and Fernando agreed, it is definitely a good idea to separate new Effects from the old ones for now.[9]

There is a new scheme that Fernando is currently working on whereby we have a definition of the effects/shaders within the pipeline keep them within the pipeline folder structure; together with defining what the shader does (if applicable) so it can be controlled by a future UI. There is a very rough draft design doc for this available here http://www.zaretto.com/sites/zaretto.com/files/compositor-effects-registry.pdf [10]

Canvas support

So far, we were focused on implementing camera views in Canvas. We also keep in mind that this might be an important groundwork for what might be RTT support for effects/shaders. For that we obviously need a link between Canvas and Effects. It's kind of a good thing that both systems are completely separated and don't know of each other, we are given more freedom when it comes to joining them. This link is kind of delicate and has to be well planned out. For example Hooray (and also Thorsten, but I'm not too sure) suggested per-element effects. It'd be kind of useful to have that, but would that give us the flexibility we need? Shaders can receive many input textures and modern shaders support MRT (Multiple Render Targets) too. It makes sense to come up with some kind of well defined link between Canvas and Effects that allows for inputting/outputting canvases via effects. This would allow the same things that per-element effects would allow but with more flexibility and less overlapping functionality. [11]

What we have now, works similarly to how Rembrandt does its buffers. There is a new texture type called "canvas" that allows shaders to access any canvas texture via a texture unit, just like you'd access a normal texture from the hard drive. This removes (most) limitations of addPlacement, which can only substitute the "base" texture (unit 0). The posibilities are endless, it just needs some care and work. At the moment we could have shadow mapping outside Rembrandt just by creating a new view placed at the Sun and make it render the depth buffer to a canvas. Then every ALS shader could access this canvas and do the shadow comparison thingy. Planar reflections in the water should be kind of trivial as well, it'd just require the model-view matrix to be multiplied by a reflection matrix and the water shader could just paste the result over the water surface (with some more fancy calculations to make it pretty of course).[12]

Actually, every ALS shader could choose to access this canvas - so one can run the more detailed opacity map technique in cockpit and shadow mapping outside for instance.[13]

Availability

Would it be practical to get to a point where both the legacy and compositor CameraGroup classes can co-exist at runtime? I recently made a fix (pull request coming shortly) that involved a lot of duplicate code in the legacy and compositor code, and then I had to change compile options, recompile, etc. to test it; yuck. I'm very enthusiastic about the compositor, but it will get much more of a workout if it is compiled and available to everyone.[14]

Runtime Toggling

drop support for legacy renderer: agree - not wise. It is too early to consider doing so. Ideally, we would want a toggle between Default and Compositor pipelines while Compositor is being developed. I would keep the toggle point very simple for now - perhaps a commandline switch to activate compositor and disable default. The harder part is the refactoring necessary to allow the two approaches to coexist - one being active and the other being inactive (e.g. feature toggle - https://www.martinfowler.com/articles/feature-toggles.html) [15]

Runtime toggling for the Compositor has been discussed before. Implementing such thing is not trivial though. The legacy CameraGroup/renderer is already quite messy due to Rembrandt. Around a year ago, when I started planning the Compositor, I made the decision to keep things simple and keep the CameraGroup implementation for the compositor as a separate file, just so I wouldn't have to deal with that mess. The advantages you mention for runtime toggling are indeed very interesting, but I'm personally not interested in having to deal with the headache caused by implementing it. I seem to recall that James proposed adding a compositor build to Jenkins, that would be a nice middle ground so people can test/develop for the Compositor while keeping the legacy renderer intact.[16]

Replacing the legacy renderer

The vision is we would replace the legacy rendering with compositor; this will then allow us to clean up a lot of the hardcoded stuff that sets up the pipeline, remove the Rembrandt code and generally have a good tidy up.

Tim Moore suggested to dump the legacy renderer and going with the compositor. He did some work to eliminate the need for the far camera, and decided to gamble on doing the work with the compositor renderer instead of the legacy renderer. He had to add render buffers to the compositor pass syntax, but otherwise it went well. Going forward, other work he is doing will use the compositor.

This work uses a floating point depth buffer, the OpenGL clip control extension to restrict Z values from 0 to 1, and the scheme of reversing the Z values so that 0 is at the far plane. Tim will submit a merge request for it once he determines if something similar will work for systems that don't support clip control.[17]

Gallery

Features

  • Completely independent of other parts of the simulator, i.e. it's part of SimGear and can be used in a standalone fashion if needed, ala Canvas.
  • Although independent, its aim is to be fully compatible with the current rendering framework in FG. This includes the Effects system, CameraGroup, Rembrandt and ALS (and obviously the Canvas).
  • Its functionality overlaps Rembrandt: what can be done with Rembrandt can be done with the Compositor, but not vice versa.
  • Fully configurable via an XML interface without compromising performance (ala Effects, using PropertyList files).
  • Flexible, expandable and compatible with modern graphics.
  • It doesn't increase the hardware requirements, it expands the hardware range FG can run on. People with integrated GPUs (Intel HD etc) can run a Compositor with a single pass that renders directly to the screen like before, while people with more powerful cards can run a Compositor that implements deferred rendering, for example.
  • Static branching support. Every pipeline element can be enabled/disabled at startup via a <condition> block.

How to enable the Compositor

Currently the Compositor can only be enabled at compile time via the -DENABLE_COMPOSITOR=ON CMake flag in FlightGear. SimGear doesn't require any extra parameters. Once you have a binary with the Compositor enabled and you run it, you will be presented with the default rendering pipeline. At the time of writing, this is the low spec rendering pipeline. If you want to try the ALS pipeline, start FlightGear with the command line argument: --compositor=Compositor/ALS/als


Good to know

  • still untested, but it's supposed to work with multiple monitors [19]
  • Spot lights aren't supported yet for clustered shading, i.e. they are registered and parsed but aren't processed as lights. Point lights are, but I don't remember what's their current status regarding shaders. [20]
  • shadows are only supported on the ALS pipeline [21]
  • Transparency on trees require MSAA (anti-aliasing) [22]

Notes for aircraft developers

Lights

The Compositor introduces a new way of defining lights that is renderer agnostic, so every rendering pipeline will be able to access the lights that have been implemented like this. As of 2019/11, the only pipeline that supports dynamic lights is the ALS pipeline. The resulting light volumes can be visualized for debugging purposes by setting the property /sim/debug/show-light-volumes to true.

<light>
  <name>my-spotlight</name>
  <type>spot</type>
  <position>
    <x-m>-7.7476</x-m>
    <y-m>0</y-m>
    <z-m>-1.7990</z-m>
  </position>
  <direction>
    <x>-1.0</x>
    <y>0</y>
    <z>-0.013</z>
  </direction>
  <ambient>
    <r>0.03</r>
    <g>0.03</g>
    <b>0.03</b>
    <a>1</a>
  </ambient>
  <diffuse>
    <r>0.95</r>
    <g>0.9</g>
    <b>0.9</b>
    <a>1</a>
  </diffuse>
  <specular>
    <r>0.95</r>
    <g>0.9</g>
    <b>0.9</b>
    <a>1</a>
  </specular>
  <attenuation>
    <c>1.0</c>
    <l>0.09</l>
    <q>0.032</q>
  </attenuation>
  <spot-exponent>5</spot-exponent>
  <spot-cutoff>40</spot-cutoff>
  <range-m>50</range-m>
</light>
  • name. An <animation> will be able to reference the light by this name. Most animations will work as expected (rotate, translate, spin etc).
  • type. spot or point.
  • position. The position of the light source in model space and in meters.
  • direction. Only available in spot lights. It indicates the direction of the spotlight. This parameter can be specified in three different ways:
Direction vector Look-at point Rotation angles
A vector in model space that specifies the direction. Doesn't have to be normalized.
<x>-1.0</x>
<y>0</y>
<z>-0.013</z>
The spotlight will calculate its direction by looking at this position from the light position. The point is in model space and in meters.
<lookat-x-m>-8.031</lookat-x-m>
<lookat-y-m>0</lookat-y-m>
<lookat-z-m>-2</lookat-z-m>
A three angle rotation in degrees that rotates the spotlight around the three axes. A 0 degree angle in all axes makes the spotlight point downwards (negative Z).
<pitch-deg>90</pitch-deg>
<roll-deg>0</roll-deg>
<heading-deg>0</heading-deg>
  • ambient, diffuse and specular. Four-component vectors that specify the light color.
  • attenuation. Three-component vector where <c> specifies the constant factor, <l> specifies the linear factor and <q> specifies the quadratic factor. These factors are plugged into the OpenGL light attenuation formula Spotlight attenuation.png where d is the distance of the fragment to the light source. See this table for a list of attenuation values based on the range of the light.
  • range-m. Maximum range from the light source position in meters. This value will be used by the renderers to determine if a fragment is illuminated by this source. Every fragment outside this range isn't guaranteed to be affected by the light, even if the attenuation factor isn't 0 in that particular fragment.
  • cutoff. Only available in spot lights. It specifies the maximum spread angle of a light source. Only values in the range 0 90 are accepted. If the angle between the direction of the light and the direction from the light to the fragment being lighted is greater than the spot cutoff angle, it won't be lit.
  • exponent. Only available in spot lights. Higher spot exponents result in a more focused light source, regardless of the spot cutoff angle.
  • debug-color (Optional). Sets the color of the debug light volume. By default it's red.

Shadows

The shadow mapping algorithm can be customized entirely by the rendering pipeline. This means that each one will have its own requirements when it comes to shadows. Here are some general recommendations:

  • Use the <noshadow> animation to disable shadows on objects that don't need them. An example would be billboarded lights or really small cockpit elements that don't need shadows and would cause degraded performance.
  • Try to mark as many cockpit objects as possible as interior.
<model>
  <name>interior</name>
  <usage>interior</usage>
  <path>Aircraft/JA37/Models/ja37-interior.xml</path> <!-- All the objects that should only be seen when inside the cockpit are in this file -->
</model>
  • Unlike in Rembrandt, polygons facing the Sun are the ones used to generate the shadow map, so single sided surfaces and non-closed objects should be rendered correctly.

Pipelines

Low-Spec pipeline

A fixed function forward rendering pipeline mainly targeted to low spec systems. It imitates the classic forward pipeline used before multi-pass rendering was introduced by using two near/far cameras rendering directly to the screen.

Screenshot showing OSG stats of the Compositor-based low-spec rendering pipeline.

ALS

The ALS pipeline tries to bring multipass rendering to the current ALS framework, effectively combining the best from ALS and Project Rembrandt.

Cascaded shadow mapping

The main issue with shadow mapping in FlightGear is the complexity of the scene graph. Culling times can become huge if we don't carefully select which parts of the scene graph we want to render in the shadow maps. Some possible optimizations:

  • Study the minimum shadow map distance we can get without noticeable light leaking. Select an appropiate amount of cascades (more cascades = more passes over all geometry, and in general we want to keep the amount of forward passes to a minimum). We should have at least three cascades: the first just for cockpit/internal shadows, the second for the whole aircraft and the third for the rest of the scenery geometry. A fourth can be added if the transition between the second and the third is too harsh.
  • Improve the culling masks (simgear/scene/util/RenderConstants.hxx). The CASTSHADOW_BIT flag is present in almost every object in the scene graph. Turning this flag off for trees, random buildings and other geometry intensive objects improves framerates by a very considerable amount. Should the user be able to select which objects cast shadows?
  • Should the terrain cast shadows? The terrain is rarely steep enough to cast shadows. Apart from that, the terrain in FlightGear messes with automatic near/far computations for the shadow passes since the geometry is not tessellated enough. Also, the terrain LOD is not good enough to have decent cull times at far cascades.
  • Adding a "internal only" shadow flag for aircraft developers. This allows farther shadow cascades to cull complex objects that are only visible in the nearest cascades. (Very important optimization for aircrafts with complex cockpit geometry).

Post-processing

Gamma correction, night vision and other ALS filters should happen in a quad pass. The current filter_combined() should be left for post-processing that requires as much precision as possible - e.g. dithering to prevent banding). HDR is not a planned feature for now so ALS will be using rgba8 buffers for most of its features.

Real-time dynamic reflections

Rendering dynamically to a cubemap is possible. As with shadow mapping, minimizing the object count and number of forward passes is vital to get good performance in FlightGear. Rendering to six cubemap faces requires six forward passes, but we can render to a dual paraboloid map instead, reducing this number to two.

Transparency

When shadows (and multipass rendering in general) come into play, transparent objects have to be treated differently, even when we are dealing with a forward renderer. In OSG there are two ways to separate transparent surfaces:

  • Using RenderBins. After a single scene cull traversal, surfaces which belong to a special RenderBin type (DepthSortedBin) are removed or moved to another camera. This is how Rembrandt does it and it is the most backwards compatible approach since RenderBins can be changed directly inside Effects.
  • Using cull masks. Two separate traversals are done: one for opaque objects and another for translucent objects. This requires offering aircraft developers another way of tagging a surface as transparent. A trivial approach would be to add a new <animation> type called 'transparent', but that wouldn't be backwards compatible. Maybe we can add some kind of system where we can change cull masks inside Effects? Would that be too hacky or out of place?

Creating a custom rendering pipeline

Since the Compositor is completely data-driven, new rendering pipelines can be created by writing a custom XML pipeline definition. This section tries to document most of the available parameters, but the best and most up-to-date resource is the Compositor parsing code in SimGear (simgear/simgear/scene/viewer). See existing pipelines in fgdata/Compositor for practical examples on how to use these parameters.

Buffers

A buffer represents a texture or, more generically, a region of GPU memory.

Parameter Name Optional Value Default Value Description
name No string Passes will be able to address the buffer by this name
type No 1d, 2d, 2d-array, 2d-multisample, 3d, rect, cubemap Any texture type allowed by OpenGL
width No Any unsigned integer or screen to use the physical viewport width. The <property> tag can also be used to use a property value Texture width
screen-width-scale Yes float 1.0 If screen was used, this controls the width scaling factor
height No Any unsigned integer or screen to use the physical viewport height. The <property> tag can also be used to use a property value Texture height
screen-height-scale Yes float 1.0 If screen was used, this controls the height scaling factor
depth No Any unsigned integer. The <property> tag can also be used to use a property value Texture depth
format Yes See simgear/simgear/scene/viewer/CompositorBuffer.cxx for the latest available values rgba8 Specifies the texture format. It corresponds to the internalformat, format and type arguments of the OpenGL function glTexImage2D
min-filter, mag-filter Yes linear, linear-mipmap-linear, linear-mipmap-nearest, nearest, nearest-mipmap-linear, nearest-mipmap-nearest linear Change the minification and magnification filtering respectively
wrap-s, wrap-t, wrap-r Yes clamp, clamp-to-edge, clamp-to-border, repeat, mirror clamp-to-border They change the wrap mode for each coordinate
anisotropy Yes float 1.0
border-color Yes vec4 (0.0f, 0.0f, 0.0f, 0.0f)
shadow-comparison Yes bool true
shadow-texture-mode Yes luminance, intensity, alpha luminance
shadow-compare-func Yes never, less, equal, lequal, greater, notequal, gequal, always lequal

Passes

A pass wraps around an osg::Camera. Passes all have some common parameters:

Parameter Name Optional Value Default Value Description
clear-color, clear-accum, clear-depth and clear-stencil Yes vec4 black, black, 1.0, 0 respectively Pass clear colors
clear-mask Yes color, stencil, depth, accum color depth Pass clear mask
effect-scheme Yes Valid effect scheme name None The pass will try to use the specified effect scheme to draw every object.

Passes can render to a buffer (Render to Texture), to several buffers (Multiple Render Targets) or directly to the framebuffer. This is accomplished by the <attachment> tag. Possible parameters of an attachment are:

Parameter Name Optional Value Default Value Description
buffer No Valid buffer name The name of the buffer to output to
component No color, color0 to color15, depth, stencil, depth-stencil FBO attachment point
level Yes int 0 Mipmap level of the texture that is attached
face Yes int 0 Face of cube map texture or z-level of 3d texture
mipmap-generation Yes bool false Whether mipmap generation should be done for texture
multisample-samples Yes int 0 Multisample anti-aliasing (MSAA) samples
multisample-color-samples Yes int 0 Multisample anti-aliasing (MSAA) color samples

Passes can also receive buffers as input and use them in their shaders. This is accomplished by the <binding> tag, which has the following parameters:

Parameter Name Optional Value Default Value Description
buffer No Valid buffer name The name of the buffer to bind
unit No int The texture unit to place the texture on. Effects will be able to access the buffer on this texture unit

There are specific pass types, each with their own set of custom parameters.

scene

Renders the scene from the point of view given by the CameraGroup.

Parameter Name Optional Value Default Value Description
cull-mask Yes A 32 bit number. See simgear/simgear/scene/util/RenderConstants.hxx to know which bits enable what 0xffffffff Specifies the cull mask to be used in the underlying osg::Camera
z-near, z-far Yes int Default Z range in the CameraGroup They change the depth range to be used
cubemap-face Yes int -1 (don't use cubemap) Ignores the given view and projection matrices and uses a custom one that renders the scene as if it was seen from inside a cubemap looking towards the specified face

quad

Renders a fullscreen quad with an optional effect applied. Useful for screen space shaders (like SSAO, Screen Space Reflections or bloom) and deferred rendering.

Parameter Name Optional Value Default Value Description
geometry Yes float values for <x>, <y>, <width>, <height> 0.0, 0.0, 1.0, 1.0 respectively Size of the fullscreen quad inside the viewport using normalized coordinates.
effect Yes Valid Effect file None This Effect will be applied to the quad geometry

shadow-map

Renders the scene from a light's point of view.

Parameter Name Optional Value Default Value Description
light-name No Valid light name that exists in the scene graph The name of the osg::LightSource to use for this shadow map
near-m, far-m No Valid Effect file They specify the depth range of the shadow map

TODO

  • Bring back distortion correction.
  • $FG_ROOT/Compositor could use a per-pipeline structure, so that effects/shaders and pipelines are neatly separated and organized, this would also make it easier for maintainers to track a certain pipeline instead of having to track all changes under $FG_ROOT/Compositor (git log)
  • Some kind of versioning system to be able to make breaking changes in the future if/when the compositor is updated in any significant way, without people having to manually update their configs.
  • Bring back Canvas integration so aircraft devs have access to the rendering pipeline. This allows to render exterior views in cockpit displays etc.
  • Automatically calculate light source attenuation based on radius and radius based on attenuation.

Known Issues

  • Setting a buffer scale factor different from 1.0 and rendering to it might not scale the splash screen correctly.
  • Clustered shading crashes FG if compiled under OSG 3.6. This is related to osg::TextureBuffer changing definition from OSG 3.4 to OSG 3.6 (Images vs BufferData).

References

References
  1. Mathias Fröhlich  (Mar 7th, 2012).  Re: [Flightgear-devel] [Rembrandt] the plan .
  2. Frederic Bouvier  (Mar 7th, 2012).  Re: [Flightgear-devel] [Rembrandt] the plan .
  3. Lauri Peltonen  (Mar 7th, 2012).  [Flightgear-devel] [Rembrandt] the plan .
  4. FlightGear forum search for 'zan+rembrandt+canvas' This is a link to the FlightGear forum.
  5. https://sourceforge.net/p/flightgear/mailman/message/36578956/
  6. https://sourceforge.net/p/flightgear/mailman/message/36657975/
  7. https://sourceforge.net/p/flightgear/mailman/message/36605836/
  8. https://sourceforge.net/p/flightgear/mailman/message/36657761/
  9. https://sourceforge.net/p/flightgear/mailman/message/36657975/
  10. https://sourceforge.net/p/flightgear/mailman/message/36606242/
  11. https://forum.flightgear.org/viewtopic.php?f=47&t=32846&#p318059
  12. https://forum.flightgear.org/viewtopic.php?f=47&t=32846&hilit=canvas+view+element+offscreen#p318662
  13. https://forum.flightgear.org/viewtopic.php?f=47&t=32846&hilit=canvas+view+element+offscreen#p318693
  14. https://sourceforge.net/p/flightgear/mailman/message/36605878/
  15. https://sourceforge.net/p/flightgear/mailman/message/36657761/
  16. https://sourceforge.net/p/flightgear/mailman/message/36657975/
  17. https://sourceforge.net/p/flightgear/mailman/message/36659646/
  18. https://forum.flightgear.org/viewtopic.php?f=47&t=36269&start=45#p357570
  19. https://forum.flightgear.org/viewtopic.php?f=47&t=36269#p354669
  20. https://forum.flightgear.org/viewtopic.php?f=47&t=36269#p353179
  21. https://forum.flightgear.org/viewtopic.php?f=47&t=36269&start=60#p357586
  22. https://forum.flightgear.org/viewtopic.php?f=47&t=36269&start=45#p357580

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