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View Full Version : LW 8.2 No More Flickering Textures ???



kenmac
01-31-2005, 07:06 PM
Does anyone know or has tested if LW 8.2 no longer has the "flickering textures" problem ???

Lightwolf
02-01-2005, 02:24 AM
Does anyone know or has tested if LW 8.2 no longer has the "flickering textures" problem ???
From what I've read so far, advanced texture filtering has not been implemented in 8.2. PLD just covers general scene AA.

However, it seems that the latest SDK already contains hooks that allow for more accurate texture filtering in the future.

Cheers,
Mike

JML
02-01-2005, 06:58 AM
I have/had problems with geometry flickering but not really texture flickering...
when does that happen ? the mipmap doesn't help?
do you have some example to show?

thanks

Lightwolf
02-01-2005, 07:01 AM
Hi JML,
this happens with finely detailed textures at a grazing angle to the viewing direction (i.e. landscapes toward the horizon, edges of spheres).
Normally you'd counter this with anisotropic filtering, a feature LW currently doesn't have (basically, instead of filtering using a circular spot on an image, you use an elliptical spot, which can be very elongated in one direction).
Mip-mapping just saves time during texture filtering, but does not provide anisotropic filtering per se.

Currently, to counter the effect, you're forced to crank up the AA (i.e. more passes). Then again, the AA isn't designed to filter textures, those should be filtered at an earlier stage.

Cheers,
Mike

Lightwolf
02-01-2005, 07:06 AM
...as a side note, this will only improve the situation with image pased textures, procedurals are a completely different problem (some can filter within the algorithm, others need to be supersampled by the renderer).

Cheers,
Mike

kenmac
02-02-2005, 08:31 PM
It is ridiculous that they havenít addressed this issue.

Lightwolf
02-02-2005, 11:48 PM
It is ridiculous that they haven’t addressed this issue.
Well, I tried to code something similar as a shader (actually, I still am...), and the task at hand is not quite trivial with the data the renderer provides. I assume they'll have to mess with some of the renderer as well before they can tackle this issue.

Cheers,
Mike - who wants that to be fixed for ages too...

operation
02-03-2005, 09:25 AM
yes I am thinking to resinstall my old 8.0 version to render correctly ...
there is nothing more in those versions, but it's incredible that was not corrected !!!

If the team read this ... can you make an hurry update ( something like a 8.201 version ?) ... for TV you need to interlace !

Bobt
02-03-2005, 09:29 AM
Interlaced video on surfaces is something that LWConnect
does correctly. One of the things that I had to write to achieve
this is a special RTV Writter.
It correctly interlaces the scene. Plus you need to set the scene
up differently. There are a couple old school tricks that we found
were necessary to get interlacing to work in LW.
I figure the LW team should mention them.

Bob

JML
02-04-2005, 08:20 AM
now you mentioned it lightwolf, we had problem when rendering an animation recently,
the brick texture of our building would flicker (you will see a moire pattern on the brick)..
I thought he was doing something wrong...
now i'm worried, what if it was LW ?... I'm in the middle of a big project.. if it happens again, I'm screwed..
I don't see anything like that when I render the animation on my end, but maybe
when he convert them to 8bits, it gets worse and you can really see it.. I don't know..
and as you said, the flickers would happen only at some angles...

I noticed that there is mipmapping in LW8..
and before in LW7.5, there was something else and I did not seem to have any problem with that.
so is there a way to disable the new mipmapping and enable the old texture filtering ?

Lightwolf
02-04-2005, 08:25 AM
JML: the new mipmapping is identical to the old texture filtering, except that you have the options of conserving memory.

I think the only thing you can currently do is turn up the mip-map strength for the offending image, or use more AA passes.

Are you rendering fields? In that can cause extra flickering on very thin (i.e. 1 Pixel) horizontal lines, ich which case you could do a 1/0.5 pixel vertical guassian blur in post (and make sure to preview on a monitor that plays fields). Make sure your comp app is field aware if you blur though.

Mind you, moire patterns can show up in real footage as well.

Cheers,
Mike

JML
02-04-2005, 08:42 AM
I can only use enlow (or enmed sometimes) otherwise it would take too long..
I don't use motion blur or depth of field or fields..
just a 'normal' render..
the brick texture is 1024 by 1024 or 2048 by 2048..

if mipmap is the same as before, why did they rename it then ?
if I increase mipmapping it will get blurier, will that help remove the moire pattern if any?
and do you think converting a anim to 8bit will increase moire patterns if there is any?

thanks

Lightwolf
02-04-2005, 08:49 AM
if mipmap is the same as before, why did they rename it then ?
if I increase mipmapping it will get blurier, will that help remove the moire pattern if any?
and do you think converting a anim to 8bit will increase moire patterns if there is any?

1) I guess because in this case the term is more correct. It just makes more sense to use established terms for features.
2) Yes it will help. I guess it doesn't have to be much, like 1.5 or so. Basically, it controls how early the texturing engine will use a pixel from a lower-res, blurrier mip-map.
3) You mean after you finished rendering? Probablya bit. Since it does reduce your palette a lot, you loose those fine "gradients" that are generated during the AA pass. I assume (guessing here) that it will have more of an effect on your (geometry) AA than on the actual texture. It also depends on _how_ you convert to 8bit, what tool you use, how it picks the colours for the 8bit palette etc...

I guess a small test would help you a lot, especially early on.

Cheers,
Mike

JML
02-04-2005, 10:24 AM
thanks a lot lightwolf

JML
02-04-2005, 12:11 PM
lightwolf, the brick textures I use are 8bit tif , and before I was using 24bit jpg,
do you think that using 8 bit textures might be another cause for flickering ?

Lightwolf
02-22-2005, 06:25 AM
Sorry JML, I missed your post...

No, I don't think so. :)

Cheers,
Mike

wilgory
02-27-2005, 11:31 AM
I've been having flicker texture problems with LW v 8, 8.01 and last but not least 8.2. The object is a metallic one with a small procedural bumpmap. We have tried everything to fix it and it still plagues our animations. If this is a Ligthwave problem, I would hope that it is fixed by 8.3 because I remember people complaining about this issue years ago, like lw 6, but never encountered it until now, because I wasn't animating metal objects, etc..

Greg

brap
02-28-2005, 08:20 AM
I've been having flicker texture problems with LW v 8, 8.01 and last but not least 8.2. The object is a metallic one with a small procedural bumpmap. We have tried everything to fix it and it still plagues our animations. If this is a Ligthwave problem, I would hope that it is fixed by 8.3 because I remember people complaining about this issue years ago, like lw 6, but never encountered it until now, because I wasn't animating metal objects, etc..

Greg

I don't know if you've tried this yet, but the best solution for flickering procedual bump maps that I've found is to bake it out as a bitmap. (You'll have to copy it to the color channel first to use Surface Baker)


-Jamie