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
Hi Jay,
Soft clip being for colour is my impression, too.
Setting Detail Blending to 0 decreases my rendertimes by at least 50%.
Volker
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.
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.
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.
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.
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.
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. :)
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 :)
I have found that bigger the number for AA, the more natural and real looking populations (vegetations) turn out!!!...
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.
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?)
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?)
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
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. :)
I like njen's explanation of anti-aliasing and it fits very well with Terragen's implementation. In Terragen it also affects the quality of the motion blur if there is any. When there's a lot of complex overlapping geometry, as in distant vegetation, the image can appear excessively noisy if the AA is not high enough. There are some situations where things look sharper and more defined if you use low AA values, but as a general rule AA is a good thing.
AA affects render times in TG, but in many scenes the increase in render time is very acceptable, even with moderate amounts of motion blur. It is able to do this because AA does not usually increase the number of micro-triangles that are rendered on the terrain. The situations where AA most affects render time are usually the same situations where AA has a big improvement on image quality, e.g. with complex vegetation. In these situations higher AA can make a big difference to the number of micro-triangles that need to be rendered.
Detail Blending: During an animation involving camera movement, the subdivision levels used to create the micro-triangles will change. Detail Blending allows those micro-triangles to blend from one subdivision level to the next without a sudden pop. This blending requires more micro-triangles to be rendered, so it increases render time. It may also have a slight softening effect on the appearance of surfaces. You can reduce Detail Blending to improve render speed, but unfortunately it can also reveal very clear lines between subdivision levels on still images which often look bad and it is more difficult to control the detail levels in an image. I should be able to improve this in future by dithering the levels of detail from one micro-triangle to the next.
Soft Clip effect is a (proprietary) tone mapping which alters the brightness of pixels to improve the appearance of very bright objects in the image, giving a result more similar to photographic film than traditional 2D graphics. Most digital cameras implement something similar; it's very hard to take a nice photograph without it. Areas of the image which would otherwise be much brighter than white are brought into the visible range so that details can be seen, and it avoids hard boundaries around bright halos. Soft-clip effect, Contrast and Gamma Correction do not apply to .EXR or other HDR formats - they are only applied when saving to low dynamic range formats (BMP, TIFF etc.) or when viewing the rendered image on the monitor.
Matt
thanx for the detailed explanation....