View Full Version : Lightwave AntiAliasing

redkid one
09 September 2002, 06:28 AM
Okay, so this is a bollocks commercial job, but this problem seems to be affecting a few other jobs lately. The gaps between each section of the rollerdoor on this truck render out unevenly - it's kinda binary, either full black or no black (see image). And so, when the truck stops and rolls slowly to rest, LINES POP IN AND OUT ALL OVER THE SHOW! :annoyed: This image was rendered out of Lightwave with extreme antialiasing, and the same effect happens using field rendering and frame rendering. GRR. Anybody got any kinda solution?!

09 September 2002, 11:06 PM
Render it out at a higher resolution (maybe much higher) , and just use low or medium AA. Then resample it in Photoshop to the size you need.

Oh, I missed that it's for animation. You could still do the resizing of images in PS one by one, I suppose. But maybe there is a better program for multiple images (After Effects?). I dunno.

09 September 2002, 11:14 PM
I would strongly suggest using motionblur! This will help you getting rid of most of these motion- releated - problems and it makes everything look much more realistic.

09 September 2002, 01:06 AM
I suggest you make the gaps larger.

09 September 2002, 01:28 AM
do you need to turn Feild Rendering on?

09 September 2002, 02:21 AM

This is a normal problem with video (computer animation too). This is exactly why you don't see the major network news anchors wearing horizontal stripes. And also why you don't see mini-blinds on their set either. Technically, you will have things popping in and out if your lines are as thin or thinner than a pixel on the viewing monitor (tv is thicker, like .52 dot pitch as opposed to .21 on a nice computer monitor). The ideal solution would be to make sure the space is at least >1.5 (pixels) lines tall (at the furthest possible shot--image where vehicle is furthest from the camera).

Sorry, but that's more than likely your problem. One way to check for sure is to triple the resolution, print out one of the previously faulty frames and see if the lines magically reappear. Which they undoubtedly will. :)

Anti-aliasing makes the problem even worse by blending the color between these small lines of data.
For example, render a smaller resolution (say half of what you're using now) and you should see almost all (if not all) of your spaces disappear.

You are seeing the normal presentation interpreted by LW at the resolution you have selected.

09 September 2002, 03:05 AM
I'd try and make the space between the slats on the door a little that they'd show up in a still better. But as anim8r2 said, your more than likely going to get some nasty crawl on video because of the horizontal lines. If possible, change your camera angle to get rid of the horizontal lines (plus add some excitement to the composition of the shot). If that's just not going to please the client, you can take your frames in some sort of program that will allow image manipulation (I use After Effects) and add a slight blur (often sub-pixel) to the image. In After Effects, I have added a slight vertical blur and sometimes it helps alot without making to image look too blurry to the eye.

Hope this helps.

09 September 2002, 03:11 AM
is it using enhanced aa? or not?... as that may have some signifigance here.. apart from that i'd just eitehr render the scene out twice as large with low aa and then use after effects to shrink the image down again (and get nice smooth aa with the bars). or maybe sometimes just a lsight shift from exactly straight on can help.

09 September 2002, 05:22 AM
a variant i thought of for making the gaps thicker is to include a 2-point poly in the geometry for each gap, and have those render as a dark line 1.5 pixels thick (or more). it's more of a cheat than any of the real solutions presented here, but it might be quicker if time is an issue.

redkid one
09 September 2002, 06:00 AM
Thanks for all these replies! Yeah, i was pretty sure there was no simple solution to this - just another facet of the limitations in TV-res projects. I've got another job coming up that gonna have a whole lot of linework in it, and I'll try out all your suggestions. Cheers!:beer:

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