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View Full Version : Correct Adaptive Sampling threshold chart, finally.



Dave Jerrard
06-18-2012, 11:04 AM
I finally created a correct chart showing the Adaptive Sampling threshold ranges. This chart shows how the Adaptive Sampling passes were handled prior to LightWave 11. Note that this is VERY different from the original chart, but this time, it's correct for the release versions of 9.2 to 10.1. All threshold values are rounded to four decimal places, which is all that LightWave will display in the Camera Panel. It can use smaller values than 0.0001, but these will be rounded and only be displayed as 0.0001 or 0.0, but they will still be remembered internally and will be able to add even more passes than shown in the chart.

This chart only applies to LightWave versions from 9.2 to 10.1. LightWave 11 handles this differently.




Adaptive Sampling Pass Thresholds

AA Level Number of Adaptive Sampling Passes
none 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 0.9991 0.4998 0.25 0.125 0.0625 0.0313 0.0157 0.0079 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
1 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384
2 0.4998 0.25 0.125 0.0625 0.0313 0.0157 0.0079 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384
3 0.3333 0.1667 0.0834 0.0417 0.0209 0.0105 0.0053 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
3 6 12 24 48 96 192 384 768 1536 3072 6144 12288
4 0.25 0.125 0.0625 0.0313 0.0157 0.0079 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384
5 0.2 0.1 0.05 0.025 0.0125 0.0063 0.0032 0.0016 0.0008 0.0005 0.0002 0.0001
5 10 20 40 80 160 320 640 1280 2560 5120 10240
6 0.1667 0.0834 0.0417 0.0209 0.0105 0.0053 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
6 12 24 48 96 192 384 768 1536 3072 6144 12288
7 0.1429 0.0715 0.0358 0.0179 0.009 0.0045 0.0023 0.0012 0.0006 0.0003 0.0002 0.0001
7 14 28 56 112 224 448 896 1792 3584 7168 14336
8 0.125 0.0625 0.0313 0.0157 0.0079 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
8 16 32 64 128 256 512 1024 2048 4096 8192 16384
9 0.1111 0.0556 0.0278 0.0139 0.007 0.0035 0.0018 0.0009 0.0005 0.0003 0.0002 0.0001
9 18 36 72 144 288 576 1152 2304 4608 9216 18432
10 0.1 0.05 0.025 0.0125 0.0063 0.0032 0.0016 0.0008 0.0004 0.0002 0.0001
10 20 40 80 160 320 640 1280 2560 5120 10240
11 0.091 0.0455 0.0228 0.0114 0.0057 0.0029 0.0015 0.0008 0.0004 0.0002 0.0001
11 22 44 88 176 352 704 1408 2816 5632 11264
12 0.0833 0.0417 0.0209 0.0105 0.0053 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
12 24 48 96 192 384 768 1536 3072 6144 12288
13 0.077 0.0385 0.0193 0.0097 0.0049 0.0025 0.0013 0.0007 0.0004 0.0002 0.0001
13 26 52 104 208 416 832 1664 3328 6656 13312
14 0.0715 0.0358 0.0179 0.009 0.0045 0.0023 0.0012 0.0006 0.0003 0.0002 0.0001
14 28 56 112 224 448 896 1792 3584 7168 14336
15 0.0667 0.0334 0.0167 0.0084 0.0042 0.0021 0.0011 0.0006 0.0003 0.0002 0.0001
15 30 60 120 240 480 960 1920 3840 7680 15360
16 0.0625 0.0313 0.0157 0.0079 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
16 32 64 128 256 512 1024 2048 4096 8192 16384
17 0.0589 0.0295 0.0148 0.0074 0.0037 0.0019 0.001 0.0005 0.0003 0.0002 0.0001
17 34 68 136 272 544 1088 2176 4352 8704 17408
18 0.0556 0.0278 0.0139 0.007 0.0035 0.0018 0.0009 0.0005 0.0003 0.0002 0.0001
18 36 72 144 288 576 1152 2304 4608 9216 18432
19 0.0527 0.0264 0.0132 0.0066 0.0033 0.0017 0.0009 0.0005 0.0003 0.0002 0.0001
19 38 76 152 304 608 1216 2432 4864 9728 19456
20 0.05 0.025 0.0125 0.0064 0.0032 0.0016 0.0008 0.0004 0.0002 0.0001
20 40 80 160 320 640 1280 2560 5120 10240
21 0.0477 0.0239 0.012 0.006 0.003 0.0015 0.0008 0.0004 0.0002 0.0001
21 42 84 168 336 672 1344 2688 5376 10752
22 0.0455 0.0228 0.0114 0.0057 0.0029 0.0015 0.0008 0.0004 0.0002 0.0001
22 44 88 176 352 704 1408 2816 5632 11264
23 0.0435 0.0218 0.0109 0.0055 0.0028 0.0014 0.0007 0.0004 0.0002 0.0001
23 46 92 184 368 736 1472 2944 5888 11776
24 0.0417 0.0209 0.0105 0.0053 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
24 48 96 192 384 768 1536 3072 6144 12288
25 0.04 0.02 0.01 0.005 0.0025 0.0013 0.0007 0.0004 0.0002 0.0001
25 50 100 200 400 800 1600 3200 6400 12800
26 0.0385 0.0193 0.0097 0.0049 0.0025 0.0013 0.0007 0.0004 0.0002 0.0001
26 52 104 208 416 832 1664 3328 6656 13312
27 0.0371 0.0186 0.0093 0.0047 0.0024 0.0012 0.0006 0.0003 0.0002 0.0001
27 54 108 216 432 864 1728 3456 6912 13824
28 0.0358 0.0179 0.009 0.0045 0.0023 0.0012 0.0006 0.0003 0.0002 0.0001
28 56 112 224 448 896 1792 3584 7168 14336
29 0.0345 0.0173 0.0087 0.0043 0.0022 0.0011 0.0006 0.0003 0.0002 0.0001
29 58 116 232 464 928 1856 3712 7424 14848
30 0.0334 0.0167 0.0084 0.0042 0.0021 0.0011 0.0006 0.0003 0.0002 0.0001
30 60 120 240 480 960 1920 3840 7680 15360
31 0.0323 0.0162 0.0081 0.0041 0.0021 0.0011 0.0006 0.0003 0.0002 0.0001
31 62 124 248 496 992 1984 3968 9736 15872
32 0.0313 0.0157 0.008 0.004 0.002 0.001 0.0005 0.0003 0.0002 0.0001
32 64 128 256 512 1024 2048 4096 8192 16384
33 0.0304 0.0152 0.0076 0.0038 0.0019 0.001 0.0005 0.0003 0.0002 0.0001
33 66 132 264 528 1056 2112 4224 8448 16896
34 0.0295 0.0148 0.0074 0.0037 0.0019 0.001 0.0005 0.0003 0.0002 0.0001
34 68 136 272 544 1088 2176 4352 8704 17408
35 0.0286 0.0143 0.0072 0.0036 0.0018 0.0009 0.0005 0.0003 0.0002 0.0001
35 70 140 280 560 1120 2240 4480 8960 17920
36 0.0278 0.014 0.007 0.0035 0.0018 0.0009 0.0005 0.0003 0.0002 0.0001
36 72 144 288 576 1152 2304 4608 9216 18432
37 0.0271 0.0136 0.0068 0.0034 0.0017 0.0009 0.0005 0.0003 0.0002 0.0001
37 74 148 296 592 1184 2368 4736 9472 18944
38 0.0264 0.0132 0.0066 0.0033 0.0017 0.0009 0.0005 0.0003 0.0002 0.0001
38 76 152 304 608 1216 2432 4864 9728 19456
39 0.0257 0.0129 0.0065 0.0033 0.0017 0.0009 0.0005 0.0003 0.0002 0.0001
39 78 156 312 624 1248 2496 4992 9984 19968
40 0.025 0.0125 0.0063 0.0032 0.0016 0.0008 0.0004 0.0002 0.0001
40 80 160 320 640 1280 2560 5120 10240
41 0.0244 0.0122 0.0061 0.0031 0.0016 0.0008 0.0004 0.0002 0.0001
41 82 164 328 656 1312 2624 5248 10496
42 0.0239 0.012 0.006 0.003 0.0015 0.0008 0.0004 0.0002 0.0001
42 84 168 336 672 1344 2688 5376 10752
43 0.0233 0.0118 0.0059 0.003 0.0015 0.0008 0.0004 0.0002 0.0001
43 86 172 344 688 1376 2752 5504 11008
44 0.0228 0.0114 0.0057 0.0029 0.0015 0.0008 0.0004 0.0002 0.0001
44 88 176 352 704 1408 2816 5632 11264
45 0.0223 0.0112 0.0056 0.0028 0.0014 0.0007 0.0004 0.0002 0.0001
45 90 180 360 720 1440 2880 5760 11520
46 0.0218 0.0109 0.0055 0.0028 0.0014 0.0007 0.0004 0.0002 0.0001
46 92 184 368 736 1472 2944 5888 11776
47 0.0213 0.0107 0.0054 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
47 94 188 376 752 1504 3008 6016 12032
48 0.0209 0.0105 0.0053 0.0027 0.0014 0.0007 0.0004 0.0002 0.0001
48 96 192 384 768 1536 3072 6144 12288
49 0.0205 0.0103 0.0052 0.0026 0.0013 0.0007 0.0004 0.0002 0.0001
49 98 196 392 784 1568 3136 6272 12544
50 0.02 0.01 0.005 0.0025 0.0013 0.0007 0.0004 0.0002 0.0001
50 100 200 400 800 1600 3200 6400 12800
To keep this relatively clean I didn't put ranges in each column. Instead, each column lists the minimum threshold value for each step. The number under that is the maximum number of samples that number of passes will generate for that threshold. To find where your threshold value fit, locate the row that matches your Minimum Samples, the scan to the left, looking for the first entry that matches or is smaller than your Threshold setting. For example, the red colored entries match a threshold of 0.03, while the green ones match a threshold of 0.01. Note that as the Minimum Samples value increases, fewer passes are added, and it's possible for there to be no Adaptive Sampling Passes done at all if the value is high enough. In the above chart, when the samples are set to 34 or higher, a Threshold setting of 0.03 or larger will not have any Adaptive Sampling applied. With 100 or more, even a threshold of 0.01 will not get any additional sampling, though smaller ones will.

As you can see by looking at the right side of the chart, one pass is dropped at increasing intervals. At most intervals, the maximum samples also decreases for a given threshold. For example following the red values for a threshold of 0.03, you can see the maximum samples is 64 when the minimum is set to 1 or 2, but drops to 48 when the minimum is 3. In fact, the maximum amount for a threshold of 0.03 ranges from 34 to 66 samples.

LightWave 11 does not do this doubling of samples on each Adaptive Sampling Pass. It only does one samples per pixel for each pass, but does a lot more pass. The number of Adaptive Sampling Passes it does is entirely up to the user; this is the Maximum Samples setting. As before, LW will calculate the initial pass using the Minimum Samples, and from there, it will render any AS passes it needs until it determines the image is done, or it has reached the maximum. This lets you add as many AS passes as you need to get the quality you want, with any threshold or Minimum Samples. The maximum is no longer tied to the threshold in any way, and you no longer have to double the samples or render time to bump up the quality a bit more.

I did this for two reasons.

I've wanted to do this for a long time, but just didn't get around to it.

And to give people accurate info for their speed tests between versions of LightWave. For example I've seen some tests where a LW 11 render with Min Samples of 1, Threshold of 0.0001 and a Max of 256 was being compared to a LW 10 render with the same AA and threshold. A quick look at this chart will show that LW10 image was doing up to 16,384 samples. I'd hope that LW 11 could render 256 samples faster.


He Who Couldn't Find That Test Anywhere Now.

jeric_synergy
06-18-2012, 11:16 AM
Dave, thanks for creating this. :bowdown:

Do you happen to have it in a friendly format, like Excel or M$Word? Even ODT? I'd like to print it out.

Dave Jerrard
06-18-2012, 11:23 AM
Dave, thanks for creating this. :bowdown:

Do you happen to have it in a friendly format, like Excel or M$Word? Even ODT? I'd like to print it out.

What? Do you know how hard it was just to get that from Notepad, then to Open Office and then finally wedge that sucker into this forum? And you want more?!?! :neener:


He Who Was Tempted For A Second To Do A Full 100 Samples.

jeric_synergy
06-18-2012, 11:44 AM
What? Do you know how hard it was just to get that from Notepad, then to Open Office and then finally wedge that sucker into this forum? And you want more?!?! :neener:
:) Thanks, buddy. :thumbsup: Much obliged.

K-Dawg
06-18-2012, 12:18 PM
So if I understand this correctly.

with a AA setting of 8 to get a Sampling Pass of 128 I would have to enter 0.0079 as the threshold and to get a Sampling Pass of 4096 I would have to enter 0.0003 as the Threshold?

And to double check. If I would use a AA of 15 to get a Sampling Pass of 120 I would have to enter 0.0084 as the Threshold?

Dave Jerrard
06-18-2012, 05:11 PM
So if I understand this correctly.

with a AA setting of 8 to get a Sampling Pass of 128 I would have to enter 0.0079 as the threshold and to get a Sampling Pass of 4096 I would have to enter 0.0003 as the Threshold?

And to double check. If I would use a AA of 15 to get a Sampling Pass of 120 I would have to enter 0.0084 as the Threshold?

Anything between 0.0079 and 0.0156 would give you 4 AS passes, for a maximum of 128 samples, yes. 0.0003 to 0.0004 would give you 9 passes for 4096.

For the 120, again, you're right. Anything from 0.0079 to 0.0166 will get you 120 samples.

The values shown are the lowest values that will generate that number of passes.

Actually, you could go a slightly higher or lower since LightWave does accept more than four decimals, but it will not show them to you directly; you'd need to do use the Graph Editor or look at the scene file itself to see the full value. That 0.0003 is probably something more like 0.000625 internally, but it's rounded up. I figure 4 decimals is accurate enough though.

You can give it values of 0.00001, and get even more passes (I think this value adds another three passes), but at such low thresholds, every pixel in the image, unless it's in an absolutely solid area of color, will be tagged for rerendering, and it would make more sense to just turn the AS off and just use a high base value instead. It would probably be faster too since LW wouldn't have to check for edges anymore.


He Who Hasn't Tried More Than 5 Decimal Places.

K-Dawg
07-13-2012, 06:19 AM
Thanks for clarification Dave.

I had one more question. When I do these values my Render takes extreme long. I.E. I am rendering an old scene of mine (was a tut) and I used AA 1 at 0.0079 (128 Passes) and it took more than 30 Minutes to render. Compared to the Standard Setting Classic Camera Enhanced Medium Rendering it took 3:23 Minutes to render. Of course the AA 1 0.0079 looks better though.

Question is, When I do these settings, should I also adjust the Light Quality (i.E. Area Lights Quality from 4 to 1) and the Shader Qualities (Refraction, Reflection from 8 to like 1 or 2) and do the rendering? Will it give better results than the old with faster render times?

Greetz

rcallicotte
07-13-2012, 08:58 AM
Wow. This is amazing. Fascinating and I wish I understood it better. But, I'll hold on, while I check this out, to see what I learn. :thumbsup:

K-Dawg
07-13-2012, 09:22 AM
Ok I tried it with lowering the settings. I got the same image rendered with setting Light (2 Areas) down to a quality of 1 each and all reflective/Refractive/Transparent surfaces down to a quality to 1 too.

I set AA 1 and AS 0.0079. I got the exact same results in 6:36 as the 30 minute render with same settings except.

funny I had faster render time with low quality on light and objects and AA 6 with AS 0.0105. Took around 4:30 min.

I'll have to look into this some more, but the tests were great.

Greetz