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18. May 2018


It’s not very often a game engine takes me completely by surprise.  Especially a full featured, open source, C++ based, cross platform, heavily documented, feature rich, high performance 3D game engine.  Well that’s exactly what happened with the G3D Innovation Engine.  The primary maintainers are Morgan McGuire (@CasualEffects) who is currently an educator as well as a VR scientist at NVIDIA and previously worked on games such as Skylanders, Titan Quest and the Unity game engine, as well as Michael Mara at Standard University and Oculus Research.

The G3D Engine is self described as:

The G3D Innovation Engine is a commercial-grade C++ 3D engine available as Open Source. ss

G3D supports hardware accelerated real-time rendering, off-line rendering like ray tracing, and general purpose computation on GPUs. Its design emphasizes rapid prototyping and innovation, particularly of rendering and game algorithms.

G3D provides a set of routines and structures so common that they are needed in almost every graphics program. It makes low-level libraries like OpenGL, network sockets, and audio channels easier to use without limiting functionality or performance. G3D is a carefully designed, feature-rich base on which to prototype your 3D application.


Beyond being a capable engine it is also an incredible learning resource.  The engine is bundled with over 6GB of assets to experiment with, as well as over a dozen robust ss2samples with thoroughly documented source code.  One of the samples is even a full blown first person shooter, while another demonstrates a Minecraft-esque voxel based level.  There are also examples that show you how to work at the lowest level directly with OpenGL as well as advanced examples showcasing functionality such as real-time raytracing, lighting effects, procedural geometry and even VR.

Additionally each example can easily embed a suite of tools directly, enabling you to screen shot or video capture, change camera settings on the fly or launch the built in profiler.  There is even a complete scene editor built in, allowing you to place entities directly in your scene via simple drag and drop, turning your application into a minimalistic level editor.


Remember back at the beginning I mentioned that the maintainer was also an educator?  He has also authored a companion called the Graphics Codex which goes hand in hand with the G3D game engine.  For a mere $10 you gain access to an advanced reference that may just be one of the single best ways of learning computer graphics GIF2topics such as ray casting, BSDF, rendering and more.  You can see a full chapter list here.  So if you are trying to learn more advanced graphics programming, G3D is certainly a great resource.  Keep in mind however, this material was used with a 300s level graphics course, so you are going to need a solid foundation in math to follow along.

Purchasing the Graphics Codex is by no means a requirement however.  One thing open source projects often suffer from is poor documentation.  Thankfully this certainly isn’t the case with the G3D engine.   There is an extensive manual available here, as well as a comprehensive set of API references.  As mentioned earlier, the engine is also loaded with well documented samples.

If you are looking for a low level foundation to build your game on, a framework to do some graphical experiments or simply are looking for a way to learn more about modern graphics programming, I can think of little reason not to suggest checking out the G3D Innovation Engine. 


If you are interested in learning more about the G3D Innovation Engine, be sure to check out our hands-on video available here and embedded below.  I am almost certain you will be amazed.

GameDev News Programming


25. April 2018


The HTML5 base 3D game engine PlayCanvas has been covered several times here on GameFromScratch, both in the Closer Look series, as well as a more recent 3D game tutorial.  It has been under development for several years, but just yesterday it finally hit that biggest of milestones, a 1.0 release.  There wasn’t actually a huge number of changes in the 1.0 release, in fact there was only a single minor source change.  It’s more a sign of confidence from the PlayCanvas team about the maturity of the game engine.


From the PlayCanvas blog:

PlayCanvas was born 7 years ago, way back on 9th May 2011. In the early days, we were essentially prototyping, seeing what this amazing new WebGL API could do. By October 2011, we set up a source code repository and committed our first engine prototype. Right at the beginning, we adopted semantic versioning for naming our releases. Our initial commit generated engine v0.10.0. From that point onwards, we adopted a rapid release cadence, often publishing more than one release a week. The months and years passed, our team grew and feature after feature was integrated into the codebase. But through all that time, we never incremented the major version number. Why? Well, there were several reasons:

  1. Our rapid deployment meant we never delivered a monster release that seemed to warrant going to 1.0.0.
  2. We always made a huge effort to maintain backwards compatiblity. Projects like the inane Doom3: Gangnam Style created in December 2011 still work fine today! So we never (intentionally) broke your projects.
  3. We, uh, just never got around to it!

The PlayCanvas API is now very stable, mature and battle-hardened. Backwards compatibility is something we take very seriously indeed. And today, PlayCanvas is used in production by thousands of developers.



GameDev News


20. April 2018


Dust3D is a new application unlike any other 3D modeller I’ve used.  It’s free, open source, runs on Mac and Windows, with Linux support possible if you compile it yourself.  What makes it unique however is it’s approach to modelling.  Essentially you model by create a series of circles along two axis, which act as loft points for the generated mesh.  Really it’s one of those things you need to see in action to understand… thankfully I’ve made this video showing exactly that.



Dust is certainly not for creating highly detailed 3D models, instead it’s more useful for rapidly creating base meshes, which can then be exported in OBJ format and sculpting/refined in other 3D modelling applications.

Art


18. September 2017

In this section of our Bowling with Game Engines series, we will be implementing our bowling game using the open source Godot engine. The idea is straight forward, implement the same simple 3D game across a number of game engines. One warning right up front, this engine uses Godot 2.x on the eve of Godot 3.0 being released. Godot 3.0 will receive rather large changes to the 3D portions of Godot. We will go step by step through the process of creating our game, both in text as well as a video version available. All of the assets used in this tutorial are available on Patreon as part of the bowling game kit, along with project files and this document in PDF form. Don’t worry, these aren’t needed to follow along.  There is a video version of this entire process available here or embedded below.

First fire up Godot and create a new project. Once Godot is loaded, click New Project, then pick a location to create the project in. The project directory will be the project’s name.

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Now double click your newly created project to load it.

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Let’s start things off by creating our Title screen. Before we go too far ahead, lets create an empty node to parent our scene then save it. In the Scene panel, click the Plus Icon

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Select Node from the following dialog:

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Select the Scene menu, then Save Scene as:

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Name it TitleScene.tscn and click Save. Ok now the we have a Scene to work with, time to get to work. Let’s import the title scene image. You can use any supported texture format, but if you are working from the Patreon files, the document you want is Titlescreen.png. Select the Import Menu, then Texture

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In the following dialog, be sure to select 2D Texture, locate the texture you want to import, then click the Import button. The defaults for Texture options and format are fine. Please note, for 2D steps you can actually skip this step and directly copy the texture into your project folder using Explorer/Finder.

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Now that we have our title screen texture, it’s time to go ahead and use it. In the Scene panel, select the node we created earlier, then click the + Icon. This time we want to add a node of type TextureFrame. You can filter the options available in the node list to quickly find the node you want to create.

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Now that we’ve created a TextureFrame node, in the Inspector, locate the Texture property, drop down the menu and select Load. Select our newly loaded texture.

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Now turn the Expand property on:

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And resize the Texture to the full size of your viewport:

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Woot, most of the way there… now we want to add some looping title music that palys when the game starts. We need to import a song to use. In this case I’m using a simple WAV file that we are going to loop. The process is just like with Textures, select Import->Audio Sample

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In the resulting dialog, locate the WAV file you want to import, in options select Loop then finally select Import.

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Ok, now that we have a sound effect to play, let’s play it. In the Scene panel, select TextureFrame then click the + Icon. This time the node type we want is a sample player. Your scene should look like this now:

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Hmmm, that error Icon can’t be a good thing, can it? No worries, we just need to define the sample to play. This is going to take a couple step sthough, first we need to add a Sample Library, then add our sample to it. Don’t worry, it’s not that difficult. With the SamplePlayer selected, in the Inspector drop down the Samples option and select New SampleLibrary.

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Now select samples again and this time choose Edit.

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This brings up a new editing window:

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Click the folder icon, select your imported sample in the resulting dialog. It should then look like:

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Now in the Inspector we should be able to select our newly loaded sample in the Play menu:

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This whoever has one EXTREMELY annoying side effect… the sample will play over and over in the editor while you have this scene open. Yeah, it gets annoying fast. Time to do our first scripting instead! Let’s add some code that plays our sound when the scene is loaded… a sure way to keep sane! This means we need to add a script to node in our scene… don’t worry, its pretty easy.

We are going to create and attach a script to the TextureFrame node, the parent of our SamplePlayer. Right click the Texture Frame in the Scene panel, then select Attach Script.

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In the resulting dialog click the .. next to Path and name your file TitleScreen.gd, then click Create.

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This will bring up the script editor like so:

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Now we want to change the code like so:

func _ready():
set_process_input(true)
get_node("SamplePlayer").play("BowlingOhYeah")


Now it’s time to check out all of our hard work. Now click the Play icon:

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Since this is the first time we’ve run it, we need to tell Godot which Scene is the entry point for our application.

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Click the Select button. Then select TitleScreen.tscn in the resulting dialog. Now your application should run!

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Now of course we have to get to the guts of our actual game. Next we create our next scene where the majority of the game is going to occur. First make sure to save your existing scene if you haven’t already. Then click Scene->New Scene.

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Every scene must have at least one node. So in our newly created scene, again click the + Icon in the Scene Panel and select Node. Now save the scene as GameScene.tscn.

Perfect, now we have somewhere to go from our title screen... Next, we need to have some kind of action or trigger to switch between scenes. We are going to handle the scene change whenever the user presses any key or clicks any mouse button. This involves appending a bit of code to our script. Simply add the following function at the bottom of TitleScene.gd:

func _input(event):
  if(event.type == InputEvent.KEY || event.type == InputEvent.MOUSE_BUTTON):
  get_tree().change_scene("GameScene.tscn")

Excellent! We are now done with the Title scene… Time to move onto the main event!

If it isn’t already loaded, load up GameScene.tscn. Simply double click it in the asset view:

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Multiple scenes can be open at once and you cant toggle between them using tabs across the top of the screen. You can also switch between scripting, 2D and 3D modes. We are working in 3D in this scene, so make sure that’s selected.

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Now we are going to assemble all of the various assets we need to create our game. We have a Bowling Pin, Bowling Lane and in this example a Bowling Ball. You may note this differs from other “Bowling With” tutorials, in that in other tutorials we procedurally generate the bowling ball. In Godot 2.x there are no editor assessable geometric primitives so we instead import the bowling ball as a 3D model. There is however a plugin available for Godot that enables you to create meshes like spheres, cubes and planes that I document the use of in this video ( https://www.youtube.com/watch?v=Ca2FcVb2lBk ).


Click here for next part in the series.


The Video

Programming


18. September 2017

Click here for the previous tutorial section.

Now it’s time to create our bowling lane. If you are a Patreon, the resources we are using are located in the GFS Dropbox in the GameKits\Bowling folder. Godot works a bit different from other game engines in that complex models are imported as scenes. Simply select Import->Scene

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At a minimum select the DAE (COLLADA) file location, then the location within your project to import into, then finally click import.

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One thing that is very important to realize here is this process will import the entire scene from the model file. This includes lights, cameras, etc… so be sure when you export to DAE, you only export the items you want imported. Of course, you’ve got the option of deleting unneeded items in Godot if needed.

It is possible that the import process doesn’t always bring in the textures, so we will cover doing this part manually. If your model imported fully textured, you can skip ahead and ignore this section. First import that texture object into your scene. The bowling lane has two textures, a diffuse (color) and normal (depth) map. Select Import->Texture.

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Then select the texture, where to import it and finally hit the import button.

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Repeat this process for each texture file you need to import. Now we need to define a material on our BowlingLane node. Select the BowlingLane, locate MeshInstance->Material->0, click the drop down and select New FixedMaterial.

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This will create a new material. Drop it down again and this time select Edit.

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Now locate Diffuse, drop down the pull down and select Load.

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Select your newly imported Diffuse texture. Now repeat the process for Normal

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You can control the strength of the normal map using the Normal Depth setting:

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Your Bowling Lane should now look a lot more like a bowling lane than before!

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Now we need to add some Physics nodes to our lane. In the Scene graph, select the BowlingLane mesh instance, right click and select Add Child Node.

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Select StaticBody.

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This will make our lane part of the physics simulation, but as the name suggests, it wont be affected by it. So basically, a static body can be hit, but nothing will happen to it. Finally, we need to define the geometry of physics object. Right click your newly created StaticBody, select Add Child Node Again and this time select CollisionShape.

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With the newly created CollisionShape selected, locate Shape, drop down and select New BoxShape.

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Now select the Shape drop down again and select Edit

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Now modify the Extents until it tightly wraps the underlying shape.

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We are now done with the lane. Save the scene file and close it.

Creating the Bowling Pin

Now we repeat the exact same process, except this time with our bowling pin. The process is actually identical, except instead of creating a StaticBody, we create a PhysicsBody. However, in this case the RigidBody needs to be the parent of the Pin. Don’t worry, its pretty simple. Be sure to make the RigidBody node a child of the Root “BowlingPin” node, then drag the Pin node onto the newly created RigidBody. So we can identify the node in code later, also rename it from RigidBody to PinRigidBody. The end result should look like:

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In the properties of our RigidBody, we also want to set Can Sleep off and Contact Monitor on, like so:

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Creating our Bowling Alley

Now it’s time to put it all together. Go back to GameScene in the editor and we need to create some instances of our lane and pins. Simply locate the lane in the assets view, right click and select Instance.

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Now repeat the process for the bowling pin. Your scene should now look something like:

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Next reposition the bowling pin and so it’s above the lane and down a bit. Now it’s the moment of truth… are you a 5 pin or 10 pin fan? Either way, duplicate the first pin. Locate it in the Scene panel, right click and select duplicate ( or select and hit Ctrl + D ).

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Then move the pin into position and repeat the process. If you want, now is your chance to create 7 pin bowling! Personally, I went with 5, and it looks like this:

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5 pin for life! We are certainly getting there! It’s at least starting to feel like a bowling game. It would be a good time to check out our work, but press play and you’ll notice a problem… nothing shows up! That’s because we need to create a camera! With the root node selected, create a new node and select Camera:

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Now position the camera in your scene using the transform manipulator. With a camera node selected, you can hit the Preview button at any time to, well, preview the camera.

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Now when we press play…

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Hmm, a bit dark in here isn’t it? Well that makes sense, we have no lights in our scene. We have two options here… we can add some lights or we can add ambient lighting. Getting the later right is probably a bit easier, so lets take that approach. With the camera selected, located the Environment setting, drop it down and select New Environment

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Now drop it down again, this time selecting Edit. Now turn Ambient lighting on and select a color close to white.

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One thing you might find is that the results are really blurry and undesirable. There are two ways to address this… first, select the texture, locate the flags propert and turn off MipMap and Filtering:

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Finally, in the mesh of an imported scene, you can turn off baked lighting:

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Both of these steps are completely optional. At this point our game should look like:

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And our scene should look like:

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Now all we need is a ball!  Click here for the next tutorial section.

Programming


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