by Joao R. Grilo
Since the beginning, one of the main goals is to achieve photo realistic images. When I started my professional work, the main field of my activity was architecture visualization. Not surprisingly a common request from clients was realistic renders and light conditions simulations. I began in 1995 by using 3D Studio DOS 4. In 1996, the first 3D Studio MAX. I loved working in Max but rendering for Arch-viz was deplorable, so naturally my work flow evolved into modeling and texturing using 3ds Max and then exporting the model to Lightscape. This was a full radiosity application that could use IES data files.
Once there I just needed to insert lights and start the radiosity solution. The radiosity solution took usually took several days to complete, often with results I didn’t expect, and often I needed to recalculate the solution and then finally be ready to render.
In 3ds Max version 5, new render engines were added, such as Light Tracer which was a brute force method for global illumination. Excellent for exterior renders but way to slow and grainy. And radiosity was based on the Lightscape engine. I continued to use Lightscape since the radiosity in 3ds Max wasn’t as good. Only after the next release did I stop working with Lightscape. Autodesk announced in December 2002 that Lightscape would be discontinued.
In 2003, 3ds Max 6 was released and the Mental Ray render engine was included in the base package. Mental Ray was a render engine developed by Mental Images, Inc. and was available as a third party module for 3ds Max since 1999 (version 2.1). As I entered the Mental Ray world I realized what a powerful engine it truly was.
Global Illumination was solved as other engines in the market at the time, (Cebas -Final Render or Splutterfish- Brazil) used photons. An easy way to try and test GI solution and a fast render as well. I tested all the render engines and I continue to use Mental Ray today. Using photons was quite easy to set-up scenes that feature GI, retry different settings using the same solution, the ability to save for using in walk-throw animations.
In 3ds Max 6, a new way for generating GI was introduced. With Final Gather one could reduce the time of photon based solutions. This was quite a big feature as I was able to use medium quality photon solution and use Final Gather to add the extra step needed to create great GI renders. Also I started to often use IBL techniques. Creating moods using Hdr spherical images and complemented with lights.
In 3ds Max 7, Mental Ray added special features like SSS material support and the ILM technique for faking GI for Ambient Occlusion. My renderings were going sky high in quality. In two years I was mastering methods to get photo-realistic shading, going crazy in forums and mixing all kinds of properties for getting the correct appearance for the physical material. In this period a new third party render engine enters the market, Chaos Group V-ray, a fast ray-trace engine with a unique way to calculate GI Their contribution influenced the whole market.
I converted to V-ray starting with their public beta release. The concept of creating a material using only one base for all was quite interesting. Blurred glass, reflection, and amazing GI with unlimited light bounces at a fraction of the time, was quite impressive.
In 3ds Max 9, mental images launched Mental Ray 3.5 with Sun and Sky, a parametric real sky and sun light simulator. Also included was the Arch & Design shader, providing a full set of customizable shaders that had physical properties, and a real world camera. This was a noticeable attempt to match V-ray strengths. V-ray at the time continued to evolve better than Mental Ray, adding extra control to all the shaders, real world cameras, new SSS materials, displacements all the funky gadgets for creating highly complex renders. But complex renders came with a price, computer ram limits, Windows, and 3ds Max could not use more than 3 gigabyte of ram per process.
A common hack that I used in windows was the 3 gig switch. That involved putting code in the windows boot file and it allowed Windows to allocate the entire available RAM to only one program. Also 3ds Max 9 has its first run at a 64 bit build. For the first time, it was possible to allocate the entire ram available to the software.
V-ray came also with a way to save and manage with more RAM the use of proxies (external instanced meshes). The V-ray world and Mental Ray world became for me, a point of consideration very close to one of other, learning the best of each other. With version 2008 of 3ds Max, I leaped again to Mental Ray for some “secret” features. Features dealing with HDR, real plate composition and all the major features of V-ray were now present in Mental Ray.
With version 2008 of 3ds Max, I leaped again to Mental Ray for some “secret” features. Features dealing with HDR, real plate composition and all the major features of V-ray were now present in Mental Ray.
Another great feature was Mental Ray Sky Portals and Photographic Exposure Control, with this was it possible to illuminate perfect interiors using only an external light.
In 2009 Mental Ray, created proxies and a new BSP tree (BSP2) for better ram management. Secretly, under the hood, mental images added an attempt to get a new way method to produce GI importons and irradiance particles through the use of “ctrl_ghost_settings”. This was a really fast way that allowed infinite light bounces.
Currently I´m using 3ds Max 2011 and Maya 2011, and in both I use Mental Ray. This year Mental Ray 3.8 featured better support for importons and irradiance particles, Environment Evaluation, Functions overrides, light color temperatures, improved BSP2 ray-trace acceleration method. MetaSL Features, reworked Depth of field. MetaSl is a great way to create shaders that work across different software pipelines, perfect for crossing from Maya to 3ds Max and vice-versa. This is done using stand-alone application Mental Mill. Mental Ray now supports moving objects with GI, that is a huge hassle for fast and clean renders, now made really easy by several presets that can analyze camera path and object movement.
At this time photographic renders are but the distance of a few mouse clicks! What a difference since those DOS days!
Joao R. Grilo: Lighting and Rendering TD and Technical I&D Manager at Up Partner S.A in the Marketing and Advertising Industry, Lisbon, Portugal. It was been using Autodesk software since 1995, since then it as been devoted to study light and camera effects in C.G. Today leads a creative team , creating Vfx for Advertise in Portugal.