Up until just a few days ago, I’ve hated Mental Ray for one thing – lack of image motion blur. It could be that it has always been there, and that I’ve never figured it out – but that has always been a big issue for me, and I’ve never found an answer for that problem.
Why do I want image motion blur instead of object motion blur? simple – it’s a thousand times faster, and works really well for most things. Of course, since it only stores one frame of direction, you will always get a straight blur – but in many cases that’s good enough.
Anyways, I playing around with various rendering settings – and was going to adjust the glare output shader, when I discovered something I hadn’t seen before – or, I must have seen it, but I have always overlooked it: The HDR Image Motion Blur shader.
HDR Image Motion Blur Shader
After googling a bit on it, it seems that it was a feature added with the 2010 release. And here I’ve been using 3ds Max 2010 for almost 10 months without discovering it… Oh well.
So why write about it? Well, I’m thinking if I can miss it, there is probably someone else that has missed it as well… (I hope…)
Sparks HDR Image Motion Blur
Sparks with no motion blur
Don’t mind the quality of the sparks-system though, just a scene I had previously done some really quick testing on. And, it also looks better when rendered out as a sequence.
So far I’ve only experimented with the “Shutter Duration” and “Shutter Falloff” settings. Shutter Duration is fairly simple, it’s how many frames the lens should be “open”. The Shutter Falloff is how quickly the blur becomes transparent. A higher value equals a more transparent motion blur.
I’ve rendered a quick bouncing balls-scene here, with SD=1, SF=2. It might be slightly too high duration, but at the same time you almost get a little squash-n-stretch-effect from it as it is now.
Imagularis 