Third-Person Navigation (with Avatar) component in Castle Game Engine

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We present a new Castle Game Engine component TCastleThirdPersonNavigation. You can use it easily with TCastleViewport to have a working 3rd-person navigation. This means that you control an avatar with keys (ASWD QE), and the mouse orbits around the avatar, who is displayed and animated in front of the camera.


  • You can move the camera around the avatar and control the avatar in various ways. All the inputs are configurable.
  • Avatar can run, crouch, with collisions, with gravity.

  • Camera follows avatar smoothly and avoids being blocked by walls.

  • Mouse can optionally also “aim” the avatar, which makes it easier to rotate the avatar. OTOH, it makes it harder to look at avatar’s front, e.g. at avatar’s face.

  • You can look closer/further at the avatar.

  • Avatar can have gravity enabled, so it can fall down and climb stairs correctly.

It is all documented in our API. There’s a lot of published properties to play with.

You can trivially use it with CGE editor. Just select a viewport and, using the menu, change the Navigation to be TCastleThirdPersonNavigation. Remember to also assign the Avatar property.

The full demo is in engine sources, in examples/third_person_camera. Just download the latest engine and open “examples/third_person_camera/” project in the CGE editor.

The examples/fps_game was also updated to show how to use 3rd-person navigation together with TPlayer and TLevel classes. Just uncomment SetupThirdPersonNavigation call in the sample code to have it working.

This work has been sponsored through Castle Game Engine Patreon. In particular thanks to Ramazan Geven and Robert Daniel Murphy for donating and requesting this feature! If you like what I’m doing — please support me on Patreon. Thank you!

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FPC 3.2.0 released, compatible with CGE, Docker images updated

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FPC (Free Pascal Compiler) logo

Great news: New major version of FPC (Free Pascal Compiler), the compiler of our game engine, was just released. New features are documented here. You can get it e.g. from SourceForge or using latest fpcupdeluxe.

Castle Game Engine is of course 100% compatible with it. I was watching and testing FPC SVN branch leading to this release. So I encourage everyone to upgrade their FPC installations. As always, we recommend using CGE with the latest FPC stable.

Note: Following our supported versions docs, you can also use some older FPC versions (we will maintain compatibility with FPC >= 3.0.2). So you don’t have to upgrade, for now we promise to keep compatibility with FPC 3.0.x for the next CGE release.

Note: if for some reason you have to stick to the old Castle Game Engine 6.4, I maintain a v6.4-fixes branch with minimal CGE 6.4 changes to make it compile with FPC 3.2.0. Although I would encourage everyone to upgrade to latest CGE that will soon be released as CGE 7.0 with ton of new features.

Our Docker image has been updated to include FPC 3.2.0, and actually use it by default. See also Jenkins docs.

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Gamma Correction and Tone Mapping

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Helmet: Gamma Correct / Gamma Correct + Tone Mapping / No Gamma or Tone Mapping
Damaged Helmet: Gamma Corrected / Not Corrected
Specular Highlight: Gamma Corrected / Not Corrected
Teapot: Gamma Corrected / Not Corrected

Gamma Correction and Tone Mapping are now implemented in Castle Game Engine. They can be trivially controlled by global variables GammaCorrection (by default it is on for PBR materials) and ToneMapping.

Gamma Correction is a way of making lighting calculations more correct (see e.g. here and here for explanation; my analysis of various implementation is here).

Tone Mapping is just a fancy name for nice-looking color processing, that makes the final look more visually pleasing. It is independent from the gamma correction (technically), although they both “change the scene colors” so are often considered together. We now implement 3 tone mapping operators (based on glTF sample viewer): see TToneMapping. Note that you can easily do your own color processing (thus providing functionality equivalent to these tone-mapping operators) by using Effect node like in this example: tone_mapping.x3dv from demo models.

I wrote a new manual chapter about Gamma Correction documenting all of this, and my description of gamma correction in various engines was also extended.

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Easy property to make animation blending

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DefaultAnimationTransition in CGE editor

We introduced TCastleSceneCore.DefaultAnimationTransition property.

This is a really easy way to request animation cross-fading (blending) which makes changing animations look much smoother. Just set this to some non-zero value to have smooth animation change. It’s the time in seconds, often it’s reasonable to start with something small like 0.1.

This is also configurable in the CGE editor (as it’s a published property). Our “New Project” template 2d_game is using it.

And it’s available in resource.xml file for the creature. Our examples/fps_game/ is using it for the “knight” creature. Like this:

<model url="knight.gltf" pool="10" default_animation_transition="0.25">
  <idle   animation_name="Idle"    />
  <walk   animation_name="Walk"    />
  <attack animation_name="Attack"  />
  <die    animation_name="Die"     />
  <hurt   animation_name="Damaged" />

This also brings improved switching to the default state (like idle or walk) after Attack/Hurt. This makes animation change smoother for creatures using resource.xml, whether you use default_animation_transition or not.

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Reading punctual lights from glTF

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blender screenshot 2020-06-07 00:12:50 selection

We can now read lights from the glTF file.

The lights have to follow glTF extension KHR_lights_punctual. It’s a popular extension supported e.g. by Blender -> glTF exporter. So you can just add lights in Blender, export to glTF, open in CGE, and the lights are there!

This works for “punctual” glTF lights, which are converted in a very straightforward fashion to X3D lighting nodes: PointLight, SpotLight, DirectionalLight.


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Various API improvements (ShowUserInterfaceToQuit, SaveScreenToDefaultFile, orientation matching glTF by default) and build tool and editor improvements

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A number of improvements all across the engine:

  1. ApplicationProperties.ShowUserInterfaceToQuit. Useful to hide that “Quit” button on mobile. Used by the editor new project templates for 2D and 3D games.

  2. Saving screenshot to the best location, automatically determined: Container.SaveScreenToDefaultFile, lower-level SaveScreenPath. This is important as you cannot assume that your application can write to the current directory when installed. This featue is also already used by the editor new project templates (press F5 in 2D and 3D games).

  3. Viewport.TransformUnderMouse represents the current TCastleTransform under the mouse. It’s easier to use than lower-level Viewport.MouseRayHit.

  4. The default orientation (important if you use TCastleTransform.Direction property to rotate your models) changed from otUpYDirectionMinusZ to otUpYDirectionZ. The new default makes us work out-of-the-box intuitively with glTF models.

    I wrote a lot of text why this change, although breaking compatibility, makes sense on our page documenting upgrade process from CGE 6.4. See also manual about it.

    If you use TCastleTransform.Direction and want to restore compatibility, just set TCastleTransform.DefaultOrientation := otUpYDirectionMinusZ; somewhere early (like in the Application.OnInitialize callback).

  5. Our build tool now does output filtering to hide many useless FPC warnings that occur when using Generics.Collections. This is better than disabling these warnings through FPC command-line options, this way e.g. compiler will still warn about instantiating abstract classes.

  6. view3dscene gets a new command-line option --project, automatically used by the editor if you double-click on a scene file in your project. In effect, the castle-data:/ protocol will also work as URL for textures etc. inside X3D, glTF and other files.

  7. CGE editor has now context menu when you right-click on files section at the bottom. You can open file manager, delete the file, refresh the directory.

  8. For PointLight / SpotLight, radius < 0 means “infinity”. This is useful to convert glTF lights, that may have range equal 0 to mean infinity. So we just convert 0 to -1.

  9. New glTF tests:

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New useful project templates in the Castle Game Engine editor

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If you click on “New Project” in the Castle Game Engine editor now, it will propose 4 useful templates:

  • Empty
  • 2D game

  • 3D FPS game

  • 3D model viewer

I advise everyone, new and old engine user, to check out these templates. You can get the latest engine version from our main page, as usual. Just unpack and run bin/castle-editor executable. (Or you can get the source code from GitHub).

I tried hard to make these templates small but also very useful as a starting point.

They show how to use most important engine features (design viewports, scenes, basic UI in the editor), advise using TUIState to split your code into states, show how to react to basic input (clicking on game field to do something).

Note that “3D FPS game” doesn’t use the item/creatures logic from the CastleCreatures unit, documented in the manual about utilities for typical 3D games. Instead the 3d_fps_game presents much simpler (but also more flexible to extend) approach to implement creature AI, by dealing directly with TCastleScene.

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