Over the past few months, GPU rendering has taken a few steps forward and, whilst we are nowhere near where we need to be, it does look promising. So let’s review what has been happening.
3ds Max 2011 Quicksilver Renderer
3ds Max 2011 was released in April 2010 and took most of us by surprise when it was revealed that Autodesk had included with it the CPU / GPU Quicksilver renderer. As this was the first GPU-based renderer actually integrated into a mainstream 3d program, we were hopeful that it would provide the perfect solution to the ever increasing problem of render times.
We did some tests on Quicksilver and concluded that it is far from perfect, but that it is looking promising and should improve with future releases and service packs.
It seems ages ago now when we saw the demo of VRay RT GPU at SIGGRAPH 2009. Since then, Chaos Group have released the nearly brilliant CPU version of RT for 3ds Max.
Whilst the CPU version is a massive step forward, it is clear that we are all still waiting for the fully-fledged GPU version. Our excitement grew when we saw the most recent video by Chaos Group (released 14th May), in which they say that VRay RT on the GPU is ‘practically a completed product’ and also that a version for Maya will be available within about two months time.
They have also conducted tests which demonstrate the huge leap forward in quality and speed. Another interesting fact about RT is that it runs on OpenCL, meaning that it will run on graphics cards from both Nvidia and AMD.
The announcement of iRay, coupled with misleading documentation, has successfully managed to confuse most of the 3D industry that has been anticipating its release. Let’s try and clear things up.
Mental images, the developer, stated in their documentation that ‘iRay is provided with mental ray from version 3.8 and RealityServer from version 3.0′ and then clarify this by saying ‘iRay-enabled products feature an iRay rendering mode’.
I suppose that this statement is true, in that, mental ray when bought as a standalone product is iRay enabled, but the confusion seems to be that, whilst the 2011 releases of Autodesk products do ship with mental ray 3.8, they haven’t enabled the iRay rendering node.
iRay remains something we are very much looking forward too, but it seems that we will have to wait the best part of a year before it is integrated into the Autodesk suite of products.
iRay is an unbiased renderer meaning that there are no settings for the renderer as such, you just import or create a model set iRay running on it and watch as the image quality gets progressively better over time. Items such as materials and lighting can be changed with near instant feedback.
Many people think that this kind of workflow will be restrictive but we found quite the opposite. It feels liberating to just make edits to your materials and lights without having to worry about using render settings and tricks to improve your image quality. All of that is left to iray which uses real world physical properties to calculate its images and is extremely fast compared to traditional renderers.
There seems to be two ways in which iray and other similar renderers can fit into your existing pipeline. The first way would be to use it as a production renderer. At present, this limits you to only using mental ray materials and as iRay is not integrated into the Autodesk line up yet adds an extra step to your workflow.
The other, more sensible use, would be to use it on location with clients, so that you can get immediate feedback on colour schemes, materials and lighting.
For example, you are an interior designer and have already modelled the set in 3ds Max. You can now import the scene into iray and then light the scene and apply the materials. You could take your laptop to the client, and right there and then change anything that the client wished. This would then eliminate the back and forth nature of finalising and perfecting a job to the clients’ needs.
The rest is then up to you and your client. If they like the GPU-produced render, then fine, but if not, you could take all those tweaks made in front of the client and then re-create them in the 3ds Max, knowing that there won’t be any further changes necessary.
We are currently testing several other GPU-based renderers similar to iRay so watch this space for reviews.