ince the early days of 3D Studio Max, one of the few weak spots of the revolutionary piece of 3D software has always been its renderer. The Max scanline renderer does its job well, but it has a few major flaws. First of all, its speed leaves much to be desired when it comes to rendering complex scenes with complicated materials. If you decide to go for Blur Software's rusty old raytracer that comes with Max, it's really time for a cup of tea, or two, or three. The second shortcoming since the introduction of Max is the level of realism that could be achieved. It required quite some effort and a thorough knowledge of lighting techniques to get rid of the 'cartoony' look of the rendering result and achieve a realistic result. But I wrote "could be achieved", because the recent release of Max 5 introduced a fresh set of advanced rendering tools. These tools include the long-awaited possibility to calculate reflected light in a scene, enhancing realism by eliminating the mentioned hard contrasts between lit areas and shadow areas. But ... the improved lighting functions come with a price of their own. If you want fine quality you can now go and drink the whole Max teapot before a render is finished.

Luckily there are some really interesting third-party alternatives for the Max rendering system, in the likes of finalRender, Brazil and VRay. I mention this threesome and deliberately leave out Mental Ray and Renderman, because finalRender, Brazil and VRay are truly integrated renderers, as opposed to the conversion bridge that's necessary to connect Max to either Mental Ray or Renderman. In this review I'm going to shine a spotlight on VRay. Nope, I'm not going to write a comprehensive comparison between VRay and the other renderers. I leave that up to those guys who like to spend hours rendering scenes with each available renderer.

Let me first share a little bit of basic knowledge with you about today's advanced rendering techniques. As I mentioned before, the hottest technique of the last few years is the calculation of reflected, indirect light within a 3D environment. There are two major techniques that can achieve this blessing: radiosity and global illumination. The terminology can be a bit confusing, because radiosity is actually a global illumination approach. But the term global illumination (short: GI) has become a concept of its own, as radiosity is geometry-dependent and GI isn't, to mention a difference. In other words: the more a scene's geometry is refined by the radiosity process, the more refined the calculation of the reflected light energy will be. This can result in a huge polygon overhead and equally huge rendering time. A further restriction of radiosity is that you will have to model your scene with real-life dimensions, proportions and light strength if you want the reflected light to be accurate.

The GI approach is more artist-friendly than radiosity. Basically, GI is based upon the ancient technique of ray-tracing, but applied to determine bouncing light energy in stead of calculating bouncing reflections and/or refractions. GI is not geometry-dependent, so you can use it in any scene setup with any proportions. Then why hasn't GI already been implemented in each available 3D package years ago, like ray-traced reflections? Well, reflected light behaviour is much less predictable than your average bouncing reflection rays. Reflected light energy is a lot more self-willed and belongs more in the interesting area of fuzzy logic. One of the most complicated techniques to determine the path that light tends to travel is the Monte Carlo algorithm. Some radiosity engines use this algorithm, like the Insight renderer from Integra, but again it's too slow to be really useful for the average artist's purposes. Today's GI renderers make use of an altered, generally speedier incarnation of the Monte Carlo approach, imaginatively named "Quasi-Monte Carlo".

GI JOE
Let's have a look at a product from some of the hottest GI Joes in town. The Chaos Group from Sofia, the beautiful capital of Bulgaria, have created the VRay plug-in rendering solution for 3ds Max. After having worked with finalRender since the release of Stage-0 I must admit I have become totally addicted to the use of GI in my 3D scenes. I've always remained relatively enthousiastic about finalRender's performance and rendering results, until the day that the Chaos Group recently made the very smart marketing move of releasing a totally free cut-down version of VRay! I couldn't resist checking out this free version and it didn't take long to convince me that VRay is a worthy opponent for finalRender. One of VRay's most obvious talents is its raw speed. A scene that used to make me fetch that good ol' teapot again now didn't allow me to grab the teapot handle before the rendering was already finished! As a matter of fact, with the right settings (no GI and other heavy stuff of course) the VRay renderer can become at least twice as fast as the Max scanline renderer, with comparable image quality. But even when switching on the real deal, like GI, reflections and refractions, VRay doesn't disappoint in terms of speed and image quality.

VRay is much more than just a GI renderer. It is a complete advanced rendering solution. For example it also offers the rendering of caustics. Caustics are reflected highlights from direct light hitting glass, water, chrome or other highly reflective surfaces. Like with using GI, I was again pleasantly surprised by VRay's ease of use. After a short struggle with some spinner values and the scene's light intensity my trusty Max teapot already produced an intricate caustic pattern. Other VRay features include a small collection of special camera lenses and real 3D motion blur. But there is more...! VRay completely ensconses itself into the Max interface and also offers a special VRay volume light that can take on a rectangular or a spherical shape, as opposed to the volumeless point source lights that ship with Max. If you prefer the standard set of Max lights, then you can make use of the VRay Shadow type, that offers faster area shadows than the ones that come with Max 5. When you open the material editor you can choose to use the VRay Material, offering some advanced options like true Fresnel reflection, advanced translucency, glossy reflections and refractions. If you prefer to keep using the standard Max materials, this is no problem at all. VRay is designed to work with any Max ingredient and you can still benefit from VRay's fast as greased lightning reflections and refractions by using the VRay Map in your standard reflection and/or refraction map slot.

VRay comes in three shapes: VRay Free is the ultimate version to have a go at VRay and see if you like it, VRay Basic is the standard package and includes the essential features, except for a number of things, like the area light, the VRay material, support for lighting based on High Dynamic Range Images and more. To be honest the difference between VRay Free and VRay Basic is not extremely large. My advice is to spend some more money and go straight for the real thing: VRay Advanced, which includes everything mentioned in this review and more, like free distributed rendering for up to ten computers, regardless of how many processors there are in one computer.

THE CONCLUSION
As said before, for quite some time I've been a faithful user of finalRender from the Germany-based company Cebas. I guess I can't avoid that my fresh enthousiasm for VRay makes me a deserter. Although VRay is still in a relatively early development stage, it already feels very stable and ready for production. At the time I write this I haven't tried Brazil yet, but somehow VRay keeps giving me the results I expect to see, without having to wrestle with a discouraging multitude of complicated settings and without having to drink gallons of tea while waiting for a rendering to be completed.

Metin Seven

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