Anti-Aliasing?

Buzzzzz · September 12, 2007, 10:10:07 AM

Been wondering about how much Anti-Aliasing to apply to a scene due to the increased render times. I've been wondering what type of Anti-Aliasing TG applies? Just for knowledge sake.

I've been playing with different combinations of AA, Detail Blending (what exactly does detail blending do? the same as AA? ) and Soft Clip Effect (Assuming this lowers contrast but not sure?) to fine a happy medium with good detail and lower render times. Personally I like to see some details rather than have everything blurred by AA. I noticed this after playing with tree bark displacements to have AA come into play and blur out the bump detail. So I lowered the AA to 2 and like what I see so far.

Please share your thoughts and/or suggestions.

Thanks
Jay

Volker Harun · September 12, 2007, 10:29:23 AM

Hi Jay,
Soft clip being for colour is my impression, too.
Setting Detail Blending to 0 decreases my rendertimes by at least 50%.

Volker

Njen · September 12, 2007, 11:54:11 AM

I am not sure what Detail Blending does, but I am pretty sure I know what AA does (well, I definitely know what it does in most of the other 3D programs). See my post here as follows. Planetside staff: if I am wrong, please let me know how TG2 treats AA...

http://forums.planetside.co.uk/index.php?topic=1821.msg18861#msg18861

What I didn't add is that higher AA settings are technically more correct, but it doesn't show it's true wroth until you do an animation. A low AA setting will see the image crawl with noise patterns. Anything lower then 3 or four would not be acceptable for animated scenes.

AA doesn't blur as such, but more correctly finds the true average value of the geometry faces that inhabit the pixel being shaded.

Personally, when I see the wonderful image you posted here: http://forums.planetside.co.uk/index.php?topic=2143.msg20777#msg20777, in order to make it more photoreal, I would definitely recommend raising the AA settings, to get rid of the harsh pixelation the fine geometry is causing in the render.

sjefen · September 12, 2007, 12:57:16 PM

I'm not sure I understand your explanation njen, but I thought Anti-Aliasing was removing pixels at the edges so it will look like it's a stright line instead of a computer drawn line like the image below shows.
Anyways. I usually set my AA to 8 or maybe 10 for the final image.

sonshine777 · September 12, 2007, 01:38:46 PM

Quote from: sjefen on September 12, 2007, 12:57:16 PM
I'm not sure I understand your explanation njen, but I thought Anti-Aliasing was removing pixels at the edges so it will look like it's a stright line instead of a computer drawn line like the image below shows.
Anyways. I usually set my AA to 8 or maybe 10 for the final image.

I think what Buzzzzz is saying about blurring things when anti-aliasing is set too high, is related to the averaging that happens when the lines are smoothed. If the render consisted of only straight lines running at angles on the screen then a high anti-aliasing setting would be great. The problem arises when the complex curves and irregular lines get smoothed, everything gets a little muddy.

Buzzzzz · September 12, 2007, 02:08:31 PM

Quote from: sonshine777 on September 12, 2007, 01:38:46 PM
Quote from: sjefen on September 12, 2007, 12:57:16 PM
I'm not sure I understand your explanation njen, but I thought Anti-Aliasing was removing pixels at the edges so it will look like it's a stright line instead of a computer drawn line like the image below shows.
Anyways. I usually set my AA to 8 or maybe 10 for the final image.

I think what Buzzzzz is saying about blurring things when anti-aliasing is set too high, is related to the averaging that happens when the lines are smoothed. If the render consisted of only straight lines running at angles on the screen then a high anti-aliasing setting would be great. The problem arises when the complex curves and irregular lines get smoothed, everything gets a little muddy.

Exactly , glad you see where I'm coming from. I'm trying to get good results using lower AA settings. That's why I would like to know the purpose of the other two options of detail blending and soft clip. Hopefully someone will chime in that knows for sure. Another problem I've been having is rendering with AA set at 3 is those with LCD monitors say things are to sharp or pixelated when on my CRT they look ok.

sonshine777 · September 12, 2007, 02:15:51 PM

Until they make LCD's with dot pitch and resolution as CRT's, I am not leaving my CRT. I have the same problem with things looking great on CRT and bad on LCD. Also I look forward to the dialog that goes on about the other settings and I will be doing some tests myself.

Buzzzzz · September 12, 2007, 02:28:33 PM

Quote from: sonshine777 on September 12, 2007, 02:15:51 PM
Until they make LCD's with dot pitch and resolution as CRT's, I am not leaving my CRT. I have the same problem with things looking great on CRT and bad on LCD. Also I look forward to the dialog that goes on about the other settings and I will be doing some tests myself.

Yeah, I just ran a crop test with detail blending set to 0 as VH said and it looked really bad even with AA set at 4. Of course it was on a tree limb section and not on just surfaces. I'll be keeping an eye open also.

BTW, Thanks to all that have replied so far.

Njen · September 12, 2007, 10:14:07 PM

As far as CRT's go, I too, work mainly on highly maintained CRT's. But all CRT's are known to blur over time. So if you think something looks right on a CRT, but pixelated on an LCD, then it maybe the CRT at fault.

My comments about AA were aimed at achieving photorealisim within renders. sonshine777: AA is the solution for complex curves and fine geometry. The more complex the geometry, the more AA is needed to produce a better result, that's the nature of 3D graphics.

Edit: I was supposed to say my comment to sonshine777, not sjefen

dhavalmistry · September 12, 2007, 10:31:56 PM

I have found that bigger the number for AA, the more natural and real looking populations (vegetations) turn out!!!...

bigben · September 12, 2007, 10:49:06 PM

Definitely agree on that one. I've been gradually increasing AA for some of my tests. I now use 4 as a default but 6 makes for some very nice trees up close.... but then I also like to render with detail = 1 (I'd actually like to use 2 but that is pushing things a bit too long

). Given that the sliders are for a "normal" range of values, the max on the AA slider is 11.

Buzzzzz · September 13, 2007, 02:47:37 PM

Was hoping someone from Planetside would explain these 2---> Detail Blending (what exactly does detail blending do? the same as AA? ) and Soft Clip Effect (Assuming this lowers contrast but not sure?)

Buzzzzz · September 13, 2007, 03:24:04 PM

bump

Was hoping someone from Planetside would explain these 2---> Detail Blending (what exactly does detail blending do? the same as AA? ) and Soft Clip Effect (Assuming this lowers contrast but not sure?)

Oshyan · September 13, 2007, 03:45:54 PM

Buzzzz, I could give a cursory explanation, but I'd rather Matt explain more precisely. He's not available at the moment but he's aware of this thread and will answer as soon as he can.

- Oshyan

Buzzzzz · September 13, 2007, 03:49:47 PM

Quote from: Oshyan on September 13, 2007, 03:45:54 PM
Buzzzz, I could give a cursory explanation, but I'd rather Matt explain more precisely. He's not available at the moment but he's aware of this thread and will answer as soon as he can.

- Oshyan

OK, Thanks for the response Oshyan.