Keep up-to-date with Free tutorials!!


Sign up to our twice-monthly newsletter today for the latest tutorials, interviews and product information.

Sign me up to receive third-party emails from 3dtotal's partners, too!

- Latest news
- Exclusive Shop Offers
- Preview early content
- Plus much more


Not Ready to take that step? OK, Why not just Subscribe to the RSS Feed

submit tutorial
1 | 2
Flicker-free FG animation with mental ray in 3ds Max

| Your Rating:
rating star fullrating star fullrating star fullrating star fullrating star half
(16 Votes)
| Comments 9
Date Added: 8th March 2012
Software used:
FG is always blamed for flickering animation and in this tutorial I'm going to share some tips about how to get flicker-free FG animation with mental ray in 3ds Max. I'll be using one of the production scenes from my latest project to demonstrate this, as it contains a large amount of polys.

So let's start with this snowy airport scene. I have enough RAM that I can render out entire scenes. The whole scene is lit with single skylight and sky texture as an environment. I also have an Environment/Background Switcher map loaded in environment slot and have used a sky Arch: Env blur shader inside the environment slot of the Switcher map. That's about it for the lighting, which is simple. Now let's talk about FG (Fig.01).


In this scene, everything is still and just the camera is moving around, so I chose Project Points Along Camera Path (as the camera is moving) and Single file mode (as everything is still and there's no animation). Also FG Bounce was set to 1 and I kepy Trace Depth to 2-1-1. I didn't need much reflection or refraction here. Noise filtering was set to None (Fig.02) and, of course, Antialiasing was set to 1-16 high settings with 0.05 default Spatial Contrast and Mitchell Filter.

Fig. 02

So I generated a FG map for every fifth frame (for 50 frames), then locked it and rendered with those AA settings and here is the result (watch in full screen with HD on) (Fig.03).


As we can see, it's flickering there. But wait, it's not FG flickering. How do we know that? There are diagnostic tools in mental ray. Go to Diagnostic tools and enable Final Gather and now render out the sequence with that enabled. The result will be like Fig.04. As we can see, all those green dots aren't moving or jumping but sticking to planes and ground (watch in full screen with HD on).


So what is the flickering then? It's antialiasing flickering. It's always antialiasing flickering not FG. FG doesn't flicker if the correct settings are chosen. Let's enable Sampling Rate and disable Final Gather in Diagnostic tools, and render out the sequence. Here is the result (watch in full screen with HD on)(Fig.05).


continued on next page >

1 | 2
Related Tutorials

'The Box'

by Aleksander Magnussen
published on 2009-12-09

Keywords: box, modeling, animation, max,

rating star fullrating star fullrating star fullrating star halfrating star none (3)
Comments 1 Views 21806

Pose to Pose Pop-Through Animation

by Keith Lango
published on 2010-12-30

Keywords: character, keyframe, animation,

rating star fullrating star fullrating star fullrating star fullrating star full (2)
Comments 3 Views 64147

Introducing Shaderlight: the new rendering plug-in for 3ds Max

by Art VPS
published on 2010-02-11

Keywords: shaderlight, plug-in, rendering, max,

rating star fullrating star nonerating star nonerating star nonerating star none (1)
Comments 0 Views 12998

Maya rigging: Introduction to rigging a human torso

by Jahirul Amin
published on 2014-02-10

Keywords: Rigging, Maya, Body, Torso, Animation

rating star fullrating star fullrating star fullrating star fullrating star half (30)
Comments 2 Views 126873
Readers Comments (Newest on Top)
Hanumant on Wed, 31 July 2013 7:04am
i want to know that did u use daylight system in rendering... what did u use for background sky... I m using mental ray for my walkthrougs... i use daylight system for lighting but cant use any backdrop... becauz when i use it my scene gets too dark... so plz tell me how to use effective backdrop...
Sebastienczaja on Thu, 28 February 2013 9:21am
Good Job!!Thanks!!!
Rawalanche on Wed, 14 March 2012 10:03am
That is usually due to the more contrast in the scene. FG does not anyhow directly accelerate AA, but if there is more even lighting in the scene with less contrasting difference, spatial AA, which works based on color contrast will have to do a bit less work. Especially when it comes to sampling area lights ;) So yeah, unified sampling, glossy reflections rays set at 1, area light samples at 2, Min1 - Max128 Unified sampling, and then all you have to do is keep raising quality parameter until render looks clean. Start at 1, and keep raising it. Value of 4-8 usually ends up being sufficient.
Jignesh Jariwala on Wed, 14 March 2012 6:48am
Good tips Rawalanche! Using less glossy and shadow samples and controlling everything with unified sampling sounds good! I will check that. As for FG, I noticed that when scene rendered without FG then it's much slower than rendered with FG on. (even with AO projected lighting, it's slower than FG)
Rawalanche on Mon, 12 March 2012 3:34pm
Actually, I am using FG all the time, but final gather has absolutely nothing to do with speed of quality of antialiasing. A few tips to optimally use unified sampling: Decrease glossy samples on all of your materials to 1. Set the samples of all your area lights to 2. Set Min 1, Max 128 samples, set cutoff to 0,025 and then control quality of your rendering using quality parameter. It will control quality of everything, including glossy reflections, DoF or Motion blur. When using unified sampling, glossy rays amount on the materials is actually a multiplier, not total ray count like in case of adaptive sampling. Make sure all your materials are modern mentalray materials, preferably Arch&Design. Never use legacy shaders (standard material, raytraced, dgs, etc..) Well tuned unified sampling will give you a LOT faster rendertimes than Min4 Max64 adaptive sampling, as well as more control over final quality.
Jignesh Jariwala on Sat, 10 March 2012 2:57pm
Hi Rawalanche, I have checked "unified sampling" and so far I found it really slow compare to quality of current adaptive sampling. Also if you are raising and getting high render times, it's mostly becoz you maynot be using FG. Using FG I rarely get high render times unless there are lots of raytraced or transperent objects. Anyway tutorial is about, how to find and eliminate flickering using diagnostic tools.
Jignesh Jariwala on Sat, 10 March 2012 2:51pm
Hi Rawalanche, I have checked "unified sampling" and so far I found it really slow compare to quality of current adaptive sampling. Anyway tutorial is about to how to find and eliminate flickering using diagnostic tools.
Rawalanche on Fri, 09 March 2012 9:03pm
Raising AA so high will give you unacceptably high rendertimes. A lot better way to eliminate flickering is to use new Unified Sampling introduced in Mental Ray 3.9, which will give you a lot better antialiasing detail at about the same time, and of course eliminate all the flickering. Also, it resolved rendered Depth of Field and Motion blur a lot faster with less noise ;)
Joshpurple on Thu, 08 March 2012 7:49pm
Great, Thank you :) !
Add Your Comment..