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pnevai
10-11-2016, 02:10 PM
I am having antialiasing issues. I have tried all sorts of sample ranges, Sampling patterns with and without adaptive sampling. But as you can see, especially in the bright highlights I get horrible jagged edges. This is a GI lit only image. No light intensity, No Ambient intensity all that is turned down to zero. This render was done with Shading samples at 16, Light samples at 16, Mitchell Sharp, Low-Discrepancy, Adaptive Sampling set .01 with 20 minimum and 120 maximum samples.
The Image world HDRI I am using is the Office_0-9_5.hdr file that came in the content folder with lightwave. Brightness set to 100%
Radiosity is Montecarlo with the default settings. I turned down the intensity of that to 80% as it was blowing out the light and reflective parts of the model at 100%
Anyone have any Ideas? I am maybe thinking that it is radiosity that is perhaps causing the jagged lines as the jagged lines are not isolated to the object edges.
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Dan Ritchie
10-11-2016, 02:32 PM
It's not a bug. Basically, since the values at those pixels are very bright, they are blowing out all nearby values. Typically your eye or a camera lens would spread the light difference out over a small space, causing a light bloom.
Fixes involve limiting the light value (not the most useful option), using a lot more AA, or using a bloom effect. Another option is rendering at a higher resolution and scaling down, but that only works if the image is 8 bit and not HDR, or it would do the same thing all over again.

spherical
10-11-2016, 02:51 PM
What Color Space are you using? The sRGB preset helps the AA by allowing LightWave to work internally Linear Color Space; which the AA engine benefits from.
Also, is Limit Dynamic Range turned on?

lertola2
10-11-2016, 02:52 PM
I am not sure but maybe checking the Limit Dynamic Range button in the render globals will help.

pnevai
10-11-2016, 03:12 PM
I will try to limit the dynamic range, but having very bright sharp highlights in renders sometimes helps with realism as often it occurs in photographs of hard shiny surfaces. Actually thank you for letting me know that this is not a error in my settings. I will also try varying levels of bloom to blend the jagged areas. The render is 720p and probably also contributing to this as there are fewer pixels to work with. Thanks again for alleviating me of more endless aliasing settings experimentation.

- - - Updated - - -

Note: There are no lights in this scene the only lighting is HDRI in LW Image World.

djwaterman
10-11-2016, 03:44 PM
Definitely increase image size to 1920/1080 at least. Did you build this Nagra?

js33
10-11-2016, 05:02 PM
Does anyone make or use tape recorders anymore?

spherical
10-11-2016, 05:43 PM
I will try to limit the dynamic range, but having very bright sharp highlights in renders sometimes helps with realism as often it occurs in photographs of hard shiny surfaces.

Just so we're clear, Limit Dynamic Range is a setting that takes care of over-bright pixels, while allowing everything else to remain as-is. It's a clamp on highlights only. ^P > Render tab > Limit Dynamic Range switch near the bottom.

Sensei
10-12-2016, 02:26 AM
If Limit Dynamic Range is not giving desired results,
you could always turn off AA (or to some basics),
and render at f.e. 4x higher resolution (it'll be like traditional 16 pass AA),
and then rescale 4x down.

pnevai
10-12-2016, 03:19 PM
Attached is the render using SRGB and Limit Dynamic range. As you can see much of the zigzag lines have been remedied. What I will do next is to render at a larger resolution and then reduce to fit. Sill some aliasing going on even in the areas without strong highlights but that must be resolution related. Or perhaps could it be that I am using the plain old perspective camera. I do not recall such issues back when the typical resolutions were 1024 X 768. I had some pretty detailed renders of small objects and I was not getting these issues, now that I think of it.134763

jwiede
10-12-2016, 06:25 PM
There's still some pretty clear aliasing of the tape on the tape heads. Regardless of whether there are workarounds, this should still be filed as a bug because it does a decent job of highlighting the problem in a fairly reproducible manner.

djwaterman
10-13-2016, 03:05 AM
Try a render at 1920 by 1080, that's the standard size these days and it will help a little in giving the image more pixels to work with. Looks pretty good to me.

MonroePoteet
10-13-2016, 09:42 AM
Have you tried a reconstruction filter other than Mitchell Sharp? A soft filter (e.g. Mitchell Soft or the Classic) might eliminate the sharpness of the specular highlights. If you don't like the overall look of a softer filter, you could matte in the softer specular highlight portions with an image editor (unless it's an animation, of course).

mTp

Nicolas Jordan
10-13-2016, 09:51 AM
To clean up jagged edges try setting "Oversample" to about 0.5. I have attached the settings I use below. These seem to work well for most renderings I do.

Dan Ritchie
10-15-2016, 10:58 AM
you could always turn off AA (or to some basics),
and render at f.e. 4x higher resolution (it'll be like traditional 16 pass AA),
and then rescale 4x down.

Just be aware that doing so in HDR would produce the same kind of aliased results as in the render, and for the same reason. Say you average so many pixels...

1,1,1,1
1,1,1,1
1,1,1,1
1,1,1,99999999

even though there are 15 pixels at a value of 1, and only one pixel with a value of 99999999, the resulting averaged pixel will still be very close to 99999999.

jwiede
10-15-2016, 05:25 PM
Yeah, the problem is that the AA stuff normally contains special biased sample arrangements to ensure high contrast edges receive some anti-aliasing, similar to thin-line retention (for power wires). Brute-force supersampling won't do anything special for those cases, which can thus worsen rather than improve problems in such situs.

For whatever reason, the AA doesn't appear to be properly detecting and enabling the special case handling everywhere appropriate in your scene. That's why I'd suggest reporting it, LW3DG folks may know settings which will enable detection and mitigation with the scene in question.

madno
10-16-2016, 03:42 AM
Some time ago I got help from geradostrada regarding this topic.
Might help you as well. It is about an image and pixel filter setup.
Attached is a test scene.

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