Sorry for the long news title and even longer news post 🙂 This is a very important bugfix and at the same time it couldn’t (reasonably) have been done in 100% backward-compatible way. We tried to explain everything below. If in doubt how to upgrade your projects (in case things will look different), don’t hesitate to contact us by forum, Discord or any other means, we’ll help! The core of the change happened in this commit on August 1st (2024), well before 7.0-alpha.3 release so it affects everyone who upgrades to engine after that date with a project created before that date.

What was fixed? A few properties of the TCastlePointLight, TCastleSpotLight and TCastleDirectionalLight had their default values applied incorrectly. That is, the default values were correct, but their effect was wrong. In particular, TCastlePointLight.Attenuation and TCastleSpotLight.Attenuation were not applied correctly.

The most visible consequence of the bug (now fixed): The default attenuation of positional lights (TCastlePointLight and TCastleSpotLight components), equal to 0 0 1 (realistic intensity falloff, following the inverse square law) was not applied. In effect, default lights didn’t have any “attenuation”, which means they were bright even on objects far away from the light position (very unrealistic). The behavior was equivalent to attenuation 0 0 0, although the property value was 0 0 1.

In short, what you may observe after the fix if you open a project created in older engine: Some of lights you have set up in your viewport (using TCastlePointLight and TCastleSpotLight) may look different, in effect your world may look darker.

Why the change is good? New lights behave in much more realistic way. It was obvious to me after doing the fix how many of our previous examples have been unrealistically bright, different than how other 3D software (like Blender or other game engines) treats positional light sources. Previous light look was incorrect, not following the attenuation value (0 0 1 behaved like 0 0 0) and not realistic (no light falloff is not realistic). The new behavior is correct, and much prettier by default.

Default intensity also changes: To account for the fact that new positional lights (TCastlePointLight and TCastleSpotLight) are much quicker fading to darkness, we also changed their default Intensity (TCastlePointLight.Intensity and TCastleSpotLight.Intensity) from 1 to 100. Previous default, 1, was too small to be useful with the new attenuation.

We also adjusted the default light setup when adding a new “Viewport (3D)” component in the editor. To make it work reasonably out of the box, useful for demos etc.

We are now more consistent with other applications. Specifically:

• Now, after the fixes, our default point light is quite like Blender’s default light. Comparing screenshots, it is obvious now they both have ~inverse square falloff, out of the box. Testing on a plane with boxes setup at 10 units around center — lighting works similar, see the screenshot in this post. This is great.

• Unity by default adds a directional light to the a new 3D scene, which naturally behaves differently than the point light (attenuation doesn’t matter, and much smaller intensity is reasonable). But if you add point light in Unity, with intensity 100, at height = 3, it behaves similarly to us — again, this is good consistency.

• We are also consistent with glTF lights, with inverse square falloff (which was why I chosen attenuation = 0 0 1 as a default long time ago). See glTF/extensions/2.0/Khronos/KHR_lights_punctual/README.md, “Within the range of the light, attenuation should follow the inverse square law as closely as possible”.

What to do to in your old projects to adjust to the new lighting?

This fix is necessarily breaking compatibility in some cases. If you relied on the fact that your positional lights by default did not have attenuation (because effectively attenuation 0 0 1 was treated like 0 0 0) then once you upgrade to the new engine version, you will notice that everything is darker.

1. The quickest, painless solution is to just set the Attenuation of the positional (point, spot) lights from 0 0 1 to 0 0 0. This disables attenuation. You can also readjust the Intensity from 100 back to 1 (without any attenuation, much smaller intensity values are reasonable).

   This is the simplest way to get back exactly the same behavior as before.

2. The alternative approach, that will take more time, but is also more recommended, is to keep the realistic attenuation (0 0 1) and adjust your light setup. We did this in all CGE examples.

   You can use more lights. You can add an additional directional light to make everything at least slightly brighter. It may even make sense to add 2 directional lights, with different directions in X and Z (but similar in Y) to simulate the daylight best. There’s no straightforward advice here, sorry — you have to experiment and decide what you want to be bright / dark, and how to achieve it using realistic lighting.

   You can also bump intensity of existing point/spot lights. It was automatically upgraded from 1 to 100, but other values (like 2) have not been adjusted. Consider increasing the intensity yourself.

Note: We looked into adding some hack to preserve the look of older setups, to keep compatibility. But it was causing more pain and complications. The problem of the old approach was not “wrong default property value” but “default property value was not properly applied”. We tried two “hacks for compatibility”, to make old lights look like they did, but they seemed both dangerous (making code really ugly to maintain) and confusing to users (since they had to essentially “activate a buggy behavior” under certain conditions). So, we decided to avoid hacks, and break compatibility, to just render stuff 100% correctly from now on.

What does not change, to be clear:

• If you have customized the attenuation of your lights previously, even very slightly (e.g. to 0 0 1.1) then it was applied OK. The bug only affected you if you left attenuation untouched, exact 0 0 1.

• Nothing changes in the way how attenuation equation matters (see X3D spec about how attenuation should be applied).

• The change doesn’t concern X3D nodes for lights (like TPointLightNode) and so nothing changes for lights you set up e.g. in Blender and exported to glTF or X3D. These look the same as before, and everything was and is correct in their case.

• The default TCastleDirectionalLight.Intensity didn’t change, it is still 1.

Things are better 🙂I (Michalis) feared this change, admittedly — as I realize this is a significant compatibility break. But after testing, and adjusting all our examples to follow it (honor attenuation = 0 0 1, physical)… everything looks so much better.

I hope you enjoy new correct and realistic lighting out-of-the-box!

Our news have been quiet in the last 2 weeks, and in effect we have a backlog of many neat new improvements to announce. So stay tuned, and be prepared for more noise than usual from our blog in the upcoming days 🙂

First of all, our presentation from Embarcadero Dev Days of Summer 2024 is available to watch on YouTube:

If you missed it (it was originally played on August 21st), we recommend you check it out! This is our latest and right now the most up-to-date presentation on how to make a new game using Castle Game Engine.

There’s an associated demo project: Pirate shooting balls at skeletons, using physics. Yeah, as the name implies, it is the most impressive and creative game ever made in 2024! 🙂

You can also browse the slides.

It makes sense for both FPC and Delphi users, naturally — as our engine supports both FPC and Delphi, and everything we show really applies to both. For Pascal editing you can use any IDE, including Delphi, Lazarus and VS Code.

We’re proud to release new version 5.2.0 of Castle Model Viewer and Castle Model Converter. They are distributed together, just head on to Castle Model Viewer downloads to get them both.

Highlights of this release (since 5.0.0):

• Engine upgraded to the finally released Castle Game Engine 7.0-alpha.3 version. The previous version was based on an engine effectively somewhere between 7.0-alpha.2 and 7.0-alpha.3.

• Reworked the shadow maps logic – much simpler now, using the shadows field at light node doesn’t process the scene graph “under the hood” anymore. Some difficult / buggy situations are thus solved and we are ready for future shadow maps improvements.

  Out of necessity, we also had to remove (already deprecated) support for using GeneratedShadowMap node in the Appearance.texture list. This was too convoluted to support (because shadow map does not affect the shape look like other textures on Appearance.texture, the shadow map effect is applied at the specific light source query). You can now only use GeneratedShadowMap inside the defaultShadwMap field of the light node.

• Float-based images support. In case of Castle Model Viewer, this means that loading 16-bit PNG images of float-based KTX images is useful for shader effects, as shaders will get full float values from the image. This extra precision sometimes matters a lot, e.g. if you use a texture for a heightmap in the shader.

• Cycle through viewpoints when you use Page Up, Page Down or the corresponding menu items.

• Fixed display when usign multiple viewports (Display -> 2 Horizontal Viewports, Display -> 4 Viewports).

Have fun with 3D! And consider supporting us on Patreon!

We are proud to present a big new release of Castle Game Engine, with lots of new features, improvements and fixes. The new engine version is available for download now.

The highlights of the release are below. For more details, see the full release notes. The number of this release, “7.0-alpha.3”, is a signal that we’re on our road to the big 7.0 release (see the roadmap and plans and timeline).

This release is dedicated to the late Eugene Loza. I miss you, dear friend.

The most important highlights of this release are:

• Physics. New components for colliders and rigid bodies, ability to run physics simulation in the editor, joints, layers, forces.

• Many rendering improvements: Correct and automatic blending, both batching and occlusion culling easier to use and more powerful, fully modern rendering on new GPUs, better support for ancient systems with old GPUs.

• Also OpenGLES (Android, iOS, Nintendo Switch) rendering supports now almost all desktop rendering features: shadow volumes, shadow maps, 3D textures, occlusion query, anisotropic filtering, meshes with 32-bit indexes.

• Shadows using shadow volumes are trivial to activate. Work is under way to expose shadow maps through a trivial property as well.

• Visual Studio Code integration. Our own VS Code “Castle Game Engine” extension with code completion and syntax highlighting for all Pascal code and easy building / running / debugging of Castle Game Engine projects.

• Delphi integration improvements: TCastleControl available for VCL and FMX applications, Delphi packages with IDE support, Delphi Linux support and more.

• Support for Tiled maps with a new component that is comfortable to use and efficient to render.

• User Interface improvements: better default font, UI batching, image regions and 9-slices borders visually configurable, mask component.

• Many editor UX improvements: modern color picker, unified tools to edit UI and transformations, wireframe view, “Change Class” menu action, Sketchfab Importer, finding components by name, multi-selection.

• Improvements to views (formerly states): better API, automatic initialization of the published fields, opening the project greets you with UX to manage views.

• Mobile improvements: lots of Android services improvements, Castle Model Viewer Mobile and more Android applications released on Google Play, lots of general Android and iOS fixes and improvements to make porting your games to mobile trivial, safe borders.

• Loading and saving: cache, MD3 improvements, X3D 4.0 improvements, custom model formats registration, STL saving.

• Inspector (press F8 / 3 fingers in a debug build of any project) improvements: tweaking boolean properties at run-time, hot-reloading at run-time to iterate on your graphics.

• Float-based images (e.g. for precise terrains) full support at loading and rendering (formats: 16-bit PNG, float-based KTX, 16/32-bit TIFFs).

• A lot of new documentation and examples. We in particular recommend 2 new tutorial articles introducing most important engine concepts: Bad way to play chess, aka 3D physics fun.

Support us

We appreciate your support on Patreon. There are also other ways to support us and if you’re a company, we’re open to cooperation (write to [email protected]). By 2024, Michalis, the lead engine developer, spent most of his life on the engine and doesn’t plan to stop. Moreover, Michalis now works on the engine full-time counting only on your support. So anything you can give is really appreciated!

Spread the word!

We don’t do much marketing. Because we suck at marketing. Help us — spread the word about this new release! Post about it anywhere you can. Talk about it in your communities — online or in the Real World. Tell your family about it (they really want to know). Reuse this news post and screenshots freely.

Have fun everyone and thank you for using the engine.

Enjoy a new example in our engine: examples/space_shooter. Features:

• Space ship (click anywhere on the screen, or use arrows, to move it).

• Background (drawn efficiently as one quad, with texture repeating to infinity).

• Rockets (fired by the player’s cannons). Each rocker has a collider and can detect when it hit an enemy. Rocket can be “armed” (destroys enemies) or “not” (just a ball that bounces off enemies).

• Enemies, played by the Mighty Rotating Rocks! They just move slowly towards the player. You can shoot them to destroy.

Technically:

• The player is just a TCastleScene inside a TCastleViewport, with input events handled in TViewMain.

• Using TCastleComponentFactory to create rockets and rocks. Each of them is defined by a reusable design.

• Using behaviors to define various behaviors of rocks and rockets.

• Using physics to handle collisions between rockets and rocks.

• Special component TTilingBackground to draw a background that (seems to) repeat to infinity. This is a reworked version of an old example background_tiling.

1. Next week, the Dev Days of Summer 2024 organized by Embarcadero starts!

   As you can guess, I’m in :), and you can watch the latest and greatest talk presenting Castle Game Engine on August 21th. The talk should make sense for all engine users, new and old — as usual I start with general engine overview, but then I go crazy and just develop a complete working game, live. I show using the editor and Pascal code (Delphi, though everything is really applicable just the same for FPC, and resulting project is compatible with both FPC and Delphi). I go through views, scenes, physics, behaviors, component factory, timers and more.

   I have finished recording the talk just this week (here’s a sneak preview of the project). During and after the talk I will of course be also available for live Q & A.

2. You can also catch me live, in person at FPC and Lazarus event in Cologne (Köln), Germany in October 2024. The event is on 10-11th October, my talk is scheduled for Friday, 11th October.

   In my talk I want to cover everything, from the game idea, through implementation using our engine, to the final deployment in Steam and Android (Google Play). I have a very intensive plan 🙂

   If you’re interested and have questions, please use the contact information at the bottom of this page. Detlef Overbeek will answer everything and help you get there.

3. Finally (with a good timing, just for those who cannot wait to see me 🙂 ) — my presentation from ITDevCon last year was recently published:

Be seeing you!

Tl;dr of this: download the latest Castle Game Engine and everything will be perfect! (or, at least: better!)

Remember that we follow continuous integration and delivery (right now using GitHub Actions) to continually release new version of the engine, 7.0-alpha.snapshot, after every commit that passes a number of automatic tests. So everything we say in these news posts is available right now in our downloads.

Recent important bugfixes:

1. Fixed frustum culling of shapes in scaled scenes.

   If you had TCastleScene with some scale, and TCastleSceneCore.PreciseCollisions, and observed disappearing shapes when rotating the camera — this is fixed now.

2. Fixed gizmos (lights, cameras) size (in editor) when they are within a scaled parent. By accident, previously the size was unreliable, could be too large for non-first child.

3. Fixed renaming components in editor on Linux / FreeBSD.

   We had a critical issue for quite some time in our editor on Linux / FreeBSD (all platforms using GTK2): occasionally, renaming components using the hierarchy tree (clicking there or using F2) was crashing. The problem was ~random, with some people experiencing it regularly, some never. 

   We have tracked the problem down to an 8-years-old Lazarus issue. Possibly, the issue was unaddressed for so long because, why the analysis of the problem was correct, the reproduction steps there were a bit difficult. Well, we have uncovered how to reproduce it easier, by editing in tree view 🙂 “Bumping” it in the Lazarus bugtracker resulted in super-quick fix from Lazarus developers — big thanks to Juha Manninen!

   If you use our official downloads, just grab the latest version and forget about it. We build using our Docker images which have Lazarus version properly patched.

   If you build Lazarus yourself, make sure to apply the relevant patch manually, as described here. Or just use latest Lazarus from “main” branch, which has this fix included.

4. Fixed crash at opening the project on macOS.

   See this merge request for details. Thanks for quick response of Lazarus devs, a version of this fix was quickly applied to Lazarus (main and fixes_3_0 branches). So just use Lazarus >= 3.5 if you build editor yourself.

5. Fixed editor packaged in our downloads on macOS. This was a silly mistake in our packing scripts, we packaged an editor for macOS, but then later script command was accidentally removing it 🙂

Note: There’s one more (really important) bugfix done lately to the lights attenuation. This will deserve a separate blog post to explain what happened. Stay tuned for future news.

Screenshot: Aston Martin Valkyrie-DVA by chiwei from Sketchfab. Traditionally, when I don’t have any special screenshot to illustrate the post, I search Sketchfab, download the model as glTF and show it rendered by our engine. This is one of the models in response to search string “bug fix” — due to same words in the description, though author of the model probably never thought someone will search Sketchfab for these words 🙂

Hi all! Today we announce a number of improvements for mobile (Android, iOS) development. They’ve been done while testing:

• Recently announced Castle Model Viewer on Android, see news.

• Updated Game Services Demo on Google Play.

• Updated Darkest Before the Dawn. A really old game developed using Castle Game Engine. Updated – no ads, use latest engine, released again on Google Play! Historically, this is the first game made for Android using Castle Game Engine, in 2013.

( Missed anything? See all Castle Game Engine applications on Google Play. )

Onward to engine improvements around the mobile:

1. TCastleContainer.SafeBorder — new property, working on both iOS and Android, exposing the safe area on screen edges where you should not draw anything important/clickable, because the system itself may draw important/clickable stuff on top of your application there.

   For example the system clock/battery/network state take space on top. The software home/back buttons may be on the bottom. Notch are present on some phones which obscure some part of some edge. See Android docs for display cutouts, and here how these displays look like. There are a few terms more-or-less interchangeable for this: safe area, insets, display cutouts on Android, status bar/bottom bar on iOS.

   Usually these are non-zero at top and bottom, but TCastleContainer.SafeBorder allows us to expose safe areas on potentially any screen side. Underlying API on Android actually gets all 4 sides. (Current code on iOS only queries for top safe area now, but we can improve it.)

   We also exposed TCastleContainer.OnSafeBorderChanged to notify about safe area changes. This is important, as applications dynamically switch orientation and/or enter/exit immersive fullscreen modes. So to support TCastleContainer.SafeBorder perfectly, make sure to react to TCastleContainer.OnSafeBorderChanged events.

   Our inspector (F8 on desktop, hold 3 fingers for 1 second on mobile) also shows them, as red bars.

   They behave OK with switchable orientations (portrait, landscape), phones and tablets and all supported Android versions, and it doesn’t break our behavior on fullscreen_immersive. This was some work to test 🙂

   How to actually support them — you need to move / enlarge your UI, to leave an extra space at the respective screen edges. You can move your UI (TCastleUserInterface.Translation), you can enlarge it (TCastleUserInterface.Height), you can use UI borders (TCastleUserInterface.Border), you can use padding available on some controls, you can also just add a solid-colored rectangle just for the sake of these insets. There’s no “automatic” answer, as you see — what to do depends on what UI you display. You can take a look what Castle Model Viewer for mobile does.

2. We have a new UI scaling method usEncloseReferenceSizeAutoOrientation. It is very similar to usEncloseReferenceSize, but automatically “flips” the reference width/height based on whether the current window sizes indicate portrait or landscape orientation. This means that UI controls have the same physical (real) size as your application orientation changes at runtime (e.g. because you support both portrait and landscape, and user just rotated the device).

   Designing for it is a bit more work. You have to account for both modes, portrait and landscape, as they result in different reference sizes. Your UI must fit sensibly in both cases.

   It is used by Castle Model Viewer for mobile so you can test it out and see how it works.

3. Gestures done with 2 fingers (on mobile) to zoom (pinch) and move (pan) with TCastleExamineNavigation have been quite improved. The code was simplified, the gestures now “kick in” instantly and they switch between pinch / pan dynamically, so you can effectively do both pinch and pan without releasing your fingers. This results in UX that feels much better to user.

   Again Castle Model Viewer for mobile is an example how it works. Run it and use 2 fingers e.g. on sample cat model to zoom/move it.

4. photo_service on Android was reimplemented to use modern approach on new Android devices and place the images reliably such that they appear in default “Photos” application.

   Using it is really trivial, just call TPhotoService.StoreImage. The full code (from castle-model-viewer-mobile) is:

   procedure TViewDisplayScene.ClickScreenshot(Sender: TObject); var Image: TRGBImage; ImageUrl: String; begin .. Image := Container.SaveScreen; try ImageUrl := FileNameAutoInc(ApplicationConfig('screenshots/'), 'screenshot_%d.png'); SaveImage(Image, ImageUrl); TPhotoService.StoreImage(ImageUrl); finally FreeAndNil(Image) end; ... end;

   procedure TViewDisplayScene.ClickScreenshot(Sender: TObject); var Image: TRGBImage; ImageUrl: String; begin .. Image := Container.SaveScreen; try ImageUrl := FileNameAutoInc(ApplicationConfig('screenshots/'), 'screenshot_%d.png'); SaveImage(Image, ImageUrl); TPhotoService.StoreImage(ImageUrl); finally FreeAndNil(Image) end; ... end;

5. We fixed saving files, when the subdirectory of the target file doesn’t exist. Our handler for saving to file:/ protocol now creates directory automatically.

   This makes sense for our engine, because we don’t want you to care about need for ForceDirectories and similar calls, because we don’t want you to usually care whether the protocol you use is file:/ or something else. We also don’t want you to depend on whether ApplicationConfig returns URL with file:/ protocol or something else (like future planned castle-config:/...). We also want constructions like SaveImage(..., ApplicationConfig('some_subdirectory/') + 'yet_another_subdirectory/foo.png'); to work automatically.

   A sample application is test_config_subdir.

6. We improved our Android documentation page (again — this seems to be most often updated documentation page of our website in 2024, maybe aside from roadmap 🙂 ). Simplified, and clearly recommends Android Studio. We work hard to make the Android process very simple and documented. At this point, installing Android Studio (not only Android command-line tools) is the best approach, IMHO — it has Java version that always works, has GUI-friendly access to emulators, mirroring, accepting licenses…

7. We improved our Android FAQ about emulator usage.

8. We improved our Android services list, to list all services and clearly specify which services are usually added automatically to the project.

That’s all, for this news announcement! We have a ton of new stuff, brace yourselves for more news 🙂 If you like this, we appreciate your support on Patreon, or other financial support , or other contributions. Reposting / resharing the news about our engine to interested people / places is in particular always appreciated!

Announcing a variety of documentation and website improvements:

1. For starters, we prepared slides highlighting Castle Game Engine features and plans. These are a nice summary of what we do and why. Just 11 slides, deliberately a short presentation. I very recommend to read and share it with everyone who may be interested in our engine!

   It has been prepared for Nicholas Polys to present our engine at SIGGRAPH 2024 highlights.

2. We have a big new section about “Baking Lighting” in our Blender documentation. This is a very powerful Blender feature, and it naturally works great in combination with our engine. We hope that this documentation helps you use it (there are a few “tricky” things to click during the process). It is accompanied with screenshots and sample model using it, in demo-models/blender/baking_lighting.

3. Inspired by a topic on our Discord, I added a section Variant records and related concepts to our modern Object Pascal introduction.

   It describes 3 Pascal features, all with examples:

   1. Variant records (example)

   2. Variant type (example)

   3. array of const and TVarRec (example)

4. We added a search box to our documentation, relying on DuckDuckGo (a privacy-friendly search engine that I use, instead of Google, for many years now, and don’t look back 🙂 ). It’s a simple search box that you can find at the bottom of the left sidebar on any page within the “Documentation” section. It searches everything in our domain that was indexed — docs, API reference, and even forum.

5. We updated and simplified our page about X3D. We tried to make it more streamlined and focus on important things (it’s an open standard and we use X3D nodes for everything). We hope this is simpler to digest than the previous version, which was complicated, at some points needlessly (e.g. most people by now probably don’t care about VRML).

6. We improved our roadmap, clearly distinguishing what we plan to do for 7.0.

7. A shout out to Reddit users: did you know we have a place to talk about Castle Game Engine on Reddit? Join there and feel welcome to talk about the engine. Eugene Loza reposts our news there, you can jump-in and comment on any news, or just start a new topic about anything you’d like.

We’re proud to officially release today Castle Model Viewer for Android!

Get it now from Google Play.

It’s a free 3D and 2D model viewer that supports all Castle Game Engine model formats: glTF, X3D, VRML, Spine JSON, sprite sheets, MD3, Wavefront OBJ, 3DS, STL, Collada, and more. It also allows to open a ZIP file that contains a single model and associated media (like textures, sounds etc.).

The viewer includes a few demo models built-in, but naturally you can also open your own model files. The important thing to remember is that models must be self-contained — we explain exactly what this means in the documentation, but the short version is: you will probably want to pack model with textures into ZIP.

Features:

• You can change navigation type (walk, fly, examine, 2D),

• jump between viewpoints,

• play chosen animations,

• save a screenshot,

• display scene statistics (triangle, vertex count) and more.

• Overall, we included the features from our desktop viewer that have been most useful, and adapted them to the mobile UI.

Have fun! If you find it useful, please support us on Patreon or a number of other ways.

The viewer is free, open-source, and has no ads or tracking naturally. Enjoy open 3D standards!

If you have any feedback, you know where to find me 🙂 Report bugs as GitHub issues. Oh, and if you like it — we’ll appreciate a 5.0 rating on Google Play 🙂

Big thanks for developing initial version of this application (originally known as view3dscene-mobile) to Jan Adamec, long-time contributor to our engine, also author of e.g. Room Arranger. It took us a lot of time before making a public release but here it finally is! Thank you!