Flyweight design pattern with C++11

To optimize the memory consumtion of the Minko engine, we started by profiling the memory allocations using tools such as the integrated Visual Studio 2013 memory profiler or Massif.

One of the heaviest source of memory allocations was for  std::string  objects. It’s not really a surprising considering one of Minko’s biggest feature is dynamic data binding between the engine data – on the CPU – and the shader data – on the GPU. And “dynamic” means we have to create those bindings according to some naming conventions and explicit declarations made in “effect” files using JSON. Read: we use lots of strings.

We use strings for material property names, but also for the camera properties or the geometry vertex attribute names. It makes the engine very flexible and extensible while keeping some important aspects of strict typing using templates. But it uses a lot of memory because each property names is stored multiple times.

Materials for example are highly likely to share most (if not all) of their property names. If you have 10 of those materials, the property name strings will use 10 times too much memory.

To solve this, I’ve implemented the flyweight design pattern.

Continue reading “Flyweight design pattern with C++11”

Exponential Cascaded Shadow Mapping with WebGL

Update: my implementation worked well on “native” OpenGL configuration but suffered from a GLSL-to-HLSL bug in the ANGLE shader cross-compiler used by Firefox and Chrome on Windows. It should now be fixed.

Update 2: you can toggle each cascade frustum using “L” and the camera frustum using “C”.

TL;DR

shadowmappingWebGL Cascaded Shadow Mapping demo powered by Minko

  • arrow keys: rotate around the scene or zoom in/out
  • C: toggle the debug display of the camera frustum
  • L: toggle the debug display of each cascade frustum
  • A: toggle shadow mapping for the 1st light
  • Z: toggle shadow mapping for the 2nd light

Motivations

Lighting is a very important part of rendering real-time convincing 3D scenes. Minko already provides a quite comprehensive set of components (DirectionalLight, SpotLight, AmbientLight, PointLight) and shaders to implement the Phong reflection model. Yet, without projected shadows, the human eye can hardly grasp the actual layout and depth of the scene.

My goal was to work on directional light projected shadows as part of a broader work to handle sun-light and a dynamic outdoor environment rendering setup (sun flares, sky, weather…).

Full code after the break…

From ActionScript 3 to C++ 2011

During the last Flash Onlince conference, I had the chance to share the latest work I’ve been involved in at Aerys with the rest of the Minko team. We’ve been working a lot on the next major version because we really want it to be a game changer for 3D on mobiles and the web.

You can read the original announcement for more details. But the big picture is that Minko is going to support WebGL. To introduce this new major feature we’ve created a first technical demonstration:

To do this, we are completely rewriting Minko using C++ 2011. This new version will include bindings for ActionScript 3 (and obviously Javascript too). So if you’re an AS3 developer: do not panic! You’ll still be able to leverage your AS3 skills with Minko. Yet if you want to learn new tricks now would be a good time and C++ is a good choice.

To understand the process of working with C++ code targeting the Flash platform and HTML5/Javascript, you can start by reading my slides:

To help AS3 developers migrating to C++, I’ve decided I’ll start gathering resources here on this very blog. If you are interested you can start by:

If you have suggestions regarding what you need to know in particular regarding C++ and especially cross-compilation targeting the Flash platform or Javascript, please let me know!

Stage3D Online Conference Slides

It was really awesome to be invited to talk about Minko today during the Stage3D online conference organized by Sergey Gonchar. He has done an excellent job in organizing this and I hope people enjoyed attending it as much as I enjoyed being a part of it.

minko_file_formats_comparison minko_editor_workflow minko_editor_triggers minko_darksider

You can watch the entire conference here.

As I promised, here are the slides to this presentation. They are pretty heavy because they embed some videos. Here is the outline of the content of the presentation:

  • Community SDK
    • Scripting
    • Shaders and GPU programming
    • Scene editor
  • Professional SDK
    • Physics
    • Optimizations for the web and mobile devices

At the end of the presentation, I also demonstrated how Minko can load and display Crytek’s Sponza smoothly on the iPad and the Nexus 7 in just a few minutes of work thanks to the editor and the optimizations granted by the MK format. You will soon here more about this very demonstration wiht a clean video demonstrating the app. but also the publishing process. This is incredibly cool since Sponza is quite a big scene with more than 50 textures including normal maps, alpha maps and specular maps for a total of 200+MB (only 70MB when published to MK).

Don’t forget to have a look at all the online resources for Minko:

As stated in the presentation, Minko’s editor public beta should start next week. So stay tuned!

New video: normal mapping and specular maps

Normal mapping has been available for a long time inside Minko. At first as part of the minko-lighting plugin and now in the core framework (in the dev branch only for now). The support for specular maps was added recently. Combining normal mapping and specular maps really gives good results. To show how far you can get, here is a little video demonstrating both techniques in the Minko editor:

New Documentation for Collada

Minko’s Collada plugin makes it possible to easily import Collada (*.dae) files using the assets loading API. Working with the API is quite simple and there already is a detailed tutorial about that. But the Collada format has its flaws and it is sometimes very complicated to get your exported files to work properly.

That’s why I’ve compiled a new documentation article that explains how to properly export Collada files from 3D Studio Max:

Export Collada files from 3D Studio Max on Aerys Hub

The article details the export procedure itself but also provides guidelines to make sure the exported file will display properly with Minko. It also give details about the supported features, including material, material properties and how the engine will use them. Similar articles will be released for different editors and formats according to the community’s needs.

Of course, as soon as the Minko editor and the MK format will be available we will strongly discourage the use of Collada files in production for many reasons (mainly performances). But you will still need to import those Collada files into the editor first… So here is a little video to show how simple importing assets is with the editor:

Yes: it’s as simple as a drag’n’drop! You will also notice that the textures load automatically and that the editor will let you play the animations and make sure everything works out of the box. The editor will be available in open beta in March…

Anamorphic Lens Flare

Update: I’ve just pushed a new SWF with a much better enhanced effect. I’ve tweaked things like the number of vertical/horizontal blur passes – which are now up to 3/6 – but also the flares’ brightness, contrast and dirt texture. I think it looks way better now!

Tonight’s experiment was focused on post-processing. My goal was to implement a simple anamorphic lens flare post-processing effect using Minko. It was actually quite simple to do. Here is the result:

minko_anamorphic_lens_flare_vipermarkII_2

The 1st pass applies a luminance threshold filter:

Then I use a multipass Gaussian blur with 4 passes: 3 horizontal passes and 1 vertical passes. The trick is to apply those 5 passes (1 luminance threshold pass + 4 blur passes) on a texture which is a lot taller than wide (32×1024 in this case). This way, everything gets streched when the flare are composited with the rest of the backbuffer.