View Full Version : LW AA or Postproduction AA

09-30-2005, 11:10 AM
Which is better... LW AA or processing the AA with a plugin for Combustion/After Effects?

09-30-2005, 11:15 AM
i didnt even know it was possible to do AA in post with combustion.
Does that work in other softares like DigitalFusion? If so how to do it?

09-30-2005, 11:20 AM
There is a built in feature with Combustion, but that doesn't work well. There is a plug-in for Combustion, Shake, and AE which works well. It does save a lot of time not having to render the AA, but my question has to deal with the quality and whether it's work it.

09-30-2005, 11:26 AM
Could you give any name on such a plug?

09-30-2005, 11:30 AM
ReelSmart Motion Blur.


09-30-2005, 12:14 PM
I would say Lw AA is wayyyyyy better than a blurplug.
I havent found any info at all that it can do any AA. Only deinterlace and some kind of fake motionblur.

09-30-2005, 01:02 PM
No that's not what I meant. With Motion blur, for the best you need to render Dithered, which doubles the amount of passes. Even with Normal it's rendering the whole screen again. You could use the adaptive sampling at a higher number of passes and then use the plugin for motion bluring. It would save so much more time. It's whether the quality would be up to snuff. I made a mistake in my last post. Sorry.

09-30-2005, 01:39 PM
Which is better... LW AA or processing the AA with a plugin for Combustion/After Effects?

Technically, only real geometry based oversampling can produce good AA or Motion Blur. Image based processes cannot achieve this since they need to reconstruct that data - either with complex algorithms that take into account motion, color bleed etc. or by simple interpolation (the latter being more widely used). So far the theory.

It's completely different if you take into account human eyesight (and its limitations). You can have a technically perfectly antialiased image and it may still look less pleasing to your eyes than a simple blurred one. This is even more noticable on stuff e.g. for video. Basically the inability of our eyes to differentiate certain tiny brightness and color differences is what makes image based motion blur and antialiasing work at all - cohesive "smooth" areas of color will be more pleasing to the brain. Of course this only works as long as the filter/ effect is able to analyze your image in a way that suits its algorithms and this is the big limitation - I've had image sequences where I could add post process motion blur on a thousand frames until one frame inbetween that could not be properly analyzed screwed everything and made the effort pointless.

To make a long story short: It's all a matter of perception and you are free to use whatever you feel appropriate. In many situations the difference are neglectible, though admitedly I would always use proper 3D AA and motion blur, if I have the chance, due to limitations mentioned. Add to that the fact that you may want to exaggerate things a bit for artistic reasons, image based AA and motion blur aren't that evil.


09-30-2005, 02:08 PM
If I render everything in passes it wont hurt as bad as applying the 3rd party motion blur to the whole image. Have you used ReelSmart Motion Blur?

But LW's motion blur is really out to lunch in the sense of realism right? I always end up with "chunks" or choppy blurs.

09-30-2005, 10:32 PM
Since motion blur relies on passes, and aa relies on passes, you'll need more when you use both. If you get steps in the motion blur, turn up the passes. I always use at least high aa for final renders that have motion blur.
No 3D motion blur renders nearly as fast as no motion blur, and it's always much slower at the high quality you need for fast motion.

In-camera 3D mot blur is the best, and I have heard good things about ReelSmart, but a test I did with some spinning sticks showed the blur going backwards half the time :hey:.
But if your motion is going very straight, you can get away with vector blur, which is quite a bit faster.

I agree that all anti-aliasing should be done in the 3D app, except maybe for quick tests -