Finally, something new! But no, it’s not any of the bigger things I’ve been hinting at before. However, I’ve been hard at work at those (and other) projects for months, and ended up with tunnel vision and an annoying rut. I really needed to do something smaller again for some immediate visual fun. When Bartek showed me something on Twitter, I decided to take a step back from all the work, dig up some half-year old code and finish it asap. And so I did: that is a Fresnel Pixel Bender shader for Away3D, presented in the FresnelPBMaterial!

I’ve explained it before, but I’ll give a more general explanation this time around. Fresnel shading mimics the way light reflects off of (often translucent) surfaces such as water or glass. Looking head-on, you can see its proper surface (or see through it with refraction). However, if seen from a shallow angle, it reflects light (just imagine looking over a large body of water, or the mirage effect on the road on hot summer days).

Demos

I’ve thrown together some rather random demos to illustrate the point. There’s source for both. (A word of warning: apparently, on some FP10.1 betas, Pixel Bender causes it to throw an invalid input exception, which seems to be bogus.)

• Glass and marble head: Yes, the head appears to be floating in the middle of a cathedral of some blurry sort. Click to cycle through different property settings: glass, alien marble (I’m sure that’s a thing), and plain marble.
• Water surface: Using an animated normal map to illustrate how water could be rendered while using the fake refraction. It also shows the WaterMap util.

Another word of warning: slight implementation details might change in the next few days/weeks, but it should be nothing too dramatic!

I’ll probably be doing something more with this when I have the time, but nothing that would likely make it to the repository

It’s no secret that I like graphics. It’s the main reason why I play video games and it’s the main reason I got into programming. So obviously I was delighted to be invited and to join to the Away3D team last month. Inspired by my earlier Stok3d project (now on the backburner for a bit), I set off to create similar normal mapped pixel shaders, this time in full 3D. After some rough first patches (Stok3d was pretty simple since it only used DisplayObjects, flat planes), things have luckily shaped up, leading up to the first release!

The current state is a dot-release (3.4.2), so the exact implementation might still change while we’re working towards a shiny new 3.5.

The new shaders

So what is the difference with the previous shaders? Using Pixel Bender, the shading is calculated for every pixel in the texture, resulting in much more detailed and realistic lighting or reflections. Each shader requires an object-space normal map, which you can use to add detailed shading information without increasing the polycount of the mesh.

The shaders come in three flavors: environment map shaders, and single- and multi-pass shaders. Single-pass shaders take one PointLight3D and any AmbientLight3D on the scene to calculate the lighting, whereas multi-pass takes any number of lights of any type (AmbientLight3D, DirectionalLight3D, and AmbientLight3D). Important to note, tho, is that every light adds another pass and will be slower. Of course, if you’re only using 1 light, always use single pass.

Check out the following classes in Google Code:

• SphericEnvMapPBMaterial:  spheric environment mapping
• Cubic EnvMapPBMaterial: cubic environment mapping

• DiffusePBMaterial: Single-pass, adds diffuse lighting to the texture
• PhongPBMaterial: Single-pass, adds diffuse lighting and specular highlights, with support for specular maps
• SpecularPBMaterial: Single-pass, adds only highlights – can be used in combination with Prefab3D‘s prebaked lighting to create view-dependent specular highlights

• DiffuseMultiPassMaterial: Diffuse shading with multiple light sources
• PhongMultiPassMaterial: Phong shading with multiple light sources

Demos

Enough explanations, time for some demos! Right-click to view source:

• Cubic environment mapping
• Single pass shading: showing how a detailed normal map and specular map can enrich the shading
• Multi pass shading: using 3 lights (directional moonlight, firefly, and a flickering flame) and ambient

That’s it, enjoy! Feel free to drop by the mailing list for questions or read the official announcement! For now, I need to get some sleep before Flash on the Beach kicks off