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elay
08-24-2011, 07:47 PM
Hi actually i tried to render a car and i cant solve the Problem with my noisy Rendering.
I uploaded a Test and the Renderglobals settings.

maybe someone can help me. I really tried a lot of setting adjustments but with no luck.

thanks in advance

VRay Version 1.50.SP1 on Win7 / Maya 2012

TaKIKO
08-26-2011, 03:14 AM
Is the noise in the reflection pass? Are you using brute force GI ?

kpamir
08-26-2011, 03:28 AM
Assuming you haven't already done this, play around with the threshold setting.

.005 gets it done for me usually.

elay
08-26-2011, 07:01 AM
Is the noise in the reflection pass? Are you using brute force GI ?

Hi these are my settings.

thanks

elay
08-26-2011, 07:07 AM
Assuming you haven't already done this, play around with the threshold setting.

.005 gets it done for me usually.

Hi i also tried a lot to play with the Threshold but with no luck.
My last threshold setting was 0.001 and it was better but not good enough and you also saw grainy or noise effect.

derMarkus
08-26-2011, 08:44 AM
Could you upload your sampler settings too, in addition to the GI settings? And how is the lighting done? Lightdome?

bigbossfr
08-26-2011, 09:20 AM
Hi actually i tried to render a car and i cant solve the Problem with my noisy Rendering.
I uploaded a Test and the Renderglobals settings.

maybe someone can help me. I really tried a lot of setting adjustments but with no luck.

thanks in advance

VRay Version 1.50.SP1 on Win7 / Maya 2012

Do you can try with my DeeX Vray Fast ?

http://deex.info/wordpress2/tools/deex-vray-fast/

elay
08-26-2011, 10:32 AM
Could you upload your sampler settings too, in addition to the GI settings? And how is the lighting done? Lightdome?

Hi i upload tonight my settings.
The lightning is done with Vray Lightdome and two Vray Rectengular Lights.

elay
08-26-2011, 10:37 AM
Do you can try with my DeeX Vray Fast ?

http://deex.info/wordpress2/tools/deex-vray-fast/

cool thanks i will give it atry. mybe it helps me

Azrail
08-26-2011, 03:06 PM
The default samples are hardly ever enough. Also the DMC sampler max subdivs and the lights' subdivisions in the scene are highly dependand one on another in a very weird way. In your case I don't know how much samples you have on your dome and lights, but with a 1/35 DMC samples you can easily raise them up to 128, even 250 if the geometry is not too heavy on detail. The DMC threshold won't help enough, only will slow down the render a lot. 0.01-0.008 is fine almost all the time.
The best way to diagnose this is to enable some render elements and check in which element the noise is happening. Three of them should be enough: rawLight, rawReflection, rawGI.

elay
08-26-2011, 03:58 PM
The default samples are hardly ever enough. Also the DMC sampler max subdivs and the lights' subdivisions in the scene are highly dependand one on another in a very weird way. In your case I don't know how much samples you have on your dome and lights, but with a 1/35 DMC samples you can easily raise them up to 128, even 250 if the geometry is not too heavy on detail. The DMC threshold won't help enough, only will slow down the render a lot. 0.01-0.008 is fine almost all the time.
The best way to diagnose this is to enable some render elements and check in which element the noise is happening. Three of them should be enough: rawLight, rawReflection, rawGI.

Thanks
i will try to set the DMC Samples up to 128 ot higher.

patrickrowan
08-26-2011, 04:35 PM
as said check your render elements and read this . it might help u see what the dmc sampler is doing and how it works so u can optimize it more.

http://www.interstation3d.com/tutorials/vray_dmc_sampler/demistyfing_dmc.html

pauldryzen
08-26-2011, 08:43 PM
Another thing could be some negative value´s in your hdri file.
They produce a lot of grain too.
Just clamp the black values to 0.

tharrell
08-27-2011, 04:50 AM
The surefire way of debugging this is to look at your raw render element passes, and set up light selects for each light in your scene to further diagnose the noise.

Basically:

- Look at raw lighting (and a raw lightselect for each light). Double light subdivs each render till raw lighting and your raw lightselects are smooth

- Look at raw reflection. If it's your entire scene that's noisy, reduce the dmc threshold very very slowly until your raw reflection pass is smooth. If it's a specific shader that's noisy and the rest of the scene is ok, just start doubling the reflection subdivs on the shader until it comes out smooth.

- Look at raw refraction, and double the specific shader's refraction subdivs till smooth.

- Look at rawgi, and up render global subdivs till smooth

- Look at reflection pass, and if I've got superbright hotspots that are resulting in jaggy aliased edges or sharp speckles, I'll generally make sure I'm using exponential color mapping and turn on subpixel mapping as well.

That's pretty much the way I approach things,

--T

elay
08-29-2011, 07:40 AM
First of all thanks guys and girls.

I tried a lot of your Tips and they was all very helpfull for me.

At least i tried the Setting Adaptive subdivisions and set the Values to :

min rate: 1
max rate: 4

threshold: 0.05

and it was much better but very slow.

if you want you can see the final render on http://www.cengil.com/all.htm
it is the Rendering ( Mercedes E Coupe ).

thanks

bigbossfr
08-29-2011, 09:29 AM
First of all thanks guys and girls.

I tried a lot of your Tips and they was all very helpfull for me.

At least i tried the Setting Adaptive subdivisions and set the Values to :

min rate: 1
max rate: 4

threshold: 0.05

and it was much better but very slow.

if you want you can see the final render on http://www.cengil.com/all.htm
it is the Rendering ( Mercedes E Coupe ).

thanks

Did you test with my tool ? :p

PerfectLine
08-30-2011, 02:05 AM
Can't really tell from the small render.... Is the noise coming from the car paint shader glossiness setting subDivs too low?

Also, if you are using a Dome light I guarantee you will need to raise the samples (which Chaos calls subdiv) up from default. To like 32-64 range to get rid of the noise.

Don't use adaptive sampling. Seriously, switch back to adaptive DMC. Min Max 1-35 was huge and would be plenty for this render. probably could go less. The ADMC threshold could be .007. Also in the DMC sampler itself you could set adaptive amount to .9 or as low as .75 (which is a higher setting) but I don't think you'll need that. Just start with the dome light and also check the glossiness subDiv settings on the car paint shader first.

Often people try to solve noise problems in Vray by attacking the render settings without realizing each shader and light also has its own subdiv settings which can clean noise for that particular effect. blurred reflections/refractions. Light shadows... etc.

They try to force the engine to clean it up which it can do to some extent but... if you just make the samples correct for each light and item then you wont need to brute force the engine at anti-aliasing time so much.

Also, vray doesn't like incorrectly facing normals at all in Maya. Make sure your normals are correct, though I don't think thats the issue here because reflections often don't work when the normals are wrong.

visua
08-30-2011, 08:04 AM
My two cents are that: 8 subdivs for brute force gi isn't nearly enough, I usually go with 30 but in the end I tend to up the global subdivs so that would be more like 60-90 in reality.

elay
08-30-2011, 12:05 PM
Did you test with my tool ? :p

actuall not but i will definetelly do

elay
08-30-2011, 12:10 PM
Often people try to solve noise problems in Vray by attacking the render settings without realizing each shader and light also has its own subdiv settings which can clean noise for that particular effect. blurred reflections/refractions. Light shadows... etc.

.

I generally use the nederhorst Settings.
I think if you use this setting you dont need to adjust the subdiv settings of the Shader, light, etc...

or i am wrong ??

and also do i really need to adjust the subdivs inthe Lightdome whenn i use the Nederhorst settings ?

thanks

PerfectLine
08-30-2011, 03:53 PM
My problem with the Nederhorst settings is that it is a broad brush stroke that is decent for many situations.

I totally disagree with raising the DMC sampler up to 1.0. The idea there is to move the sampling over to the min max and threshold but... I don't like to do that. Its more a brute force broad brush stroke method then a razor cut exactly tuned to your scene.

Since we are looking at spot 3d you may want to look at the page, if you don't believe me here, and check the DMC sampler settings. The higher that number is the more noise you introduce. A higher number in the dmc sampler is actually a lower setting.

http://www.spot3d.com/vray/help/150SP1/examples_qmc.htm

I should do another settings tutorial which is made for knowing what you are doing. I really dislike the tutorials that just say... "hey, set up like this and it will be good man".

Nederhorst is a respected artist too. Long time in Vray. So... do I say he doesn't know what he is doing... NOPE. Just that my approach is different and there are never any surprises. Yet, a vid tutorial says to use a min 2 to get extra crisp edges. Well, I still use a min 1 and I just use triangle filter because it will make a sharp edge but not as sharp as say lanzos or mitchell. Its a perfect edge sharpening filter. I mean, not everything is sharp in photos sometimes they are soft but... I have seen some super high res images that are super crisp in real life photography. Triangle filter for those crisp presentations. Trust me.

BUT, regardless of the method you go with..... IF you don't tune your shaders and light subdivs then you are just saying... I know I could reduce my render times down BUT... I just want to set up some basic settings and hope it will all work out. You need to learn where the engine is doing work in every situation.

Not addressing the dome light samples (subdiv) or not addressing the shader subDiv in the blurred reflection/refraction is just asking for longer renders that still possibly end up noisy AND more fiddling around in the render settings.

Take a scene.... put a sphere on a plane. Add a dome light. No wait, never mind, I did it for you.. Complete with the basic lookdev render settings I use.... BUT.... I left the dome light subdivs down at 8.

http://www.mediafire.com/?k2b5f17syxz7ken

Do a render. See the noise under the objects? Now set the dome light subDivs to 32 up from 8. You'll see a much cleaner non-noisy image in about the same render time.

Learn to know where the engine is doing what. You'll never be surprised. Or well much less surprised.

elay
08-31-2011, 08:42 AM
Thanks Frequenter

your definetelly right i think i need to change my Vray Settings workflow and try to understand the main Settings.

SirRender
08-31-2011, 04:56 PM
That's great info KC. I just started using VRAY for maya I too have been struggling with the noise issue.

Would it be possible for you to upload a .ma version of your Maya vray settings scene file? I'm still on Maya 2011.

So are you leaving your DMC sampler >> Adaptive Amount to the default settings of 0.850?

I'm finding that my noise issues are in my Raw Light pass. I'm just using a dome light with an HDR image. I was leaving my dome light subDivs to the default of 8 since I was changing my DMC samper amount to 1.0. No matter what I am still getting some noise in my Raw Light pass. Your posting starts to help me see why this may be happening.

Thank you very much!

patrickrowan
08-31-2011, 05:05 PM
I'm finding that my noise issues are in my Raw Light pass. I'm just using a dome light with an HDR image. I was leaving my dome light subDivs to the default of 8 since I was changing my DMC samper amount to 1.0. No matter what I am still getting some noise in my Raw Light pass. Your posting starts to help me see why this may be happening.

Thank you very much!

try upping the dome light sub div.im at 256 at the mo and theres still a little noise.

PerfectLine
08-31-2011, 06:54 PM
Would it be possible for you to upload a .ma version of your Maya vray settings scene file? I'm still on Maya 2011.

So are you leaving your DMC sampler >> Adaptive Amount to the default settings of 0.850?

I'm finding that my noise issues are in my Raw Light pass. I'm just using a dome light with an HDR image. I was leaving my dome light subDivs to the default of 8 since I was changing my DMC samper amount to 1.0. No matter what I am still getting some noise in my Raw Light pass. Your posting starts to help me see why this may be happening.

Thank you very much!

If you use the ignore version checkbox can you open it?

I do often leave it at default and even take it down in certain cases.

At DD sometimes we will use a .95 or .9 but i just leave it at .85 because its a nice solid midrange. You can save time by upping it to 1.0 but then you are definitely having to up the min max and threshold to compensate.

Remember the DMC sampler works like this.. The lower the number.. the higher the setting is. So if you raise it to 1.0 you are lowering the quality. Sure your renders are faster but... what is the point if they are noisy? Look at the spot3d page I linked. In the min max for the AA settings of course... higher numbers equal better settings but.. the threshold is the same... the lower the number the higher the quality is.

My AA threshold settings for finals usually run between .007 and .003 depending on the shot and details.

PerfectLine
08-31-2011, 07:00 PM
im at 256 at the mo and theres still a little noise.

If you are above 64 samples for a dome light with hdr and there is noise it may be due to other render settings you have tweaked. 256 is plenty for any situation. So, in that regard I wonder if the DMC sampler is set to 1 or if the surface has glossiness with low samples or of the normal is facing the right direction?

I rarely use a dome light with more then 64 samples. There are cases for it like interiors with tough small details but not in most scenarios.

SirRender
08-31-2011, 08:45 PM
Hey KC. Thanks for the explanation. Very helpful!

I checked the ignore version checkbox, but it did not work. I think it needs to be a .ma file type.

In the spot3d page, they indicate the min samples amount at 5. Are they referring to Adaptive Min Samples in the Settings >> DMC Sampler tab or the Min subdivs in the AA Adpative DMC, where you have both the Min and the Max subdivs?

The same for Noise. I'm assuming they are referring to the Threshold settings in AA Adaptive DMC?

I appreciate your patience with these rudimentary questions. The inconsistency in jargon/naming can make it a bit confusing.

Azrail
08-31-2011, 09:00 PM
If you are above 64 samples for a dome light with hdr and there is noise it may be due to other render settings you have tweaked. 256 is plenty for any situation. So, in that regard I wonder if the DMC sampler is set to 1 or if the surface has glossiness with low samples or of the normal is facing the right direction?

I rarely use a dome light with more then 64 samples. There are cases for it like interiors with tough small details but not in most scenarios.

Part of the noise may come if you are using nice hires sharp HDRIs for lighting. I think it's common practice to use some blurred version, with only colors and intensities. The details are only introducing more aliasing.

SirRender
09-01-2011, 07:13 PM
Hey KC. Just wondering if you got a chance to read my last post questions.

"In the spot3d page, they indicate the min samples amount at 5. Are they referring to Adaptive Min Samples in the Settings >> DMC Sampler tab or the Min subdivs in the AA Adpative DMC, where you have both the Min and the Max subdivs?

The same for Noise. I'm assuming they are referring to the Threshold settings in AA Adaptive DMC?"

Also, Azrail makes a good point about the HDRI maps. Back in mental ray, I frequently used a hi-res detail HDR map for reflections and a smaller blurred version for Indirect Illumination (FG), using MR mip rayswitch shader.

Does anybody how one would go about do this with VRay dome lights? I tried using two dome lights and setting the appropriate Affect Diffuse and Affect Reflections options for each, but the renders did not look correct. I think the reflections where wacked out.

Amyways, I realize that it can be done using the Environment overrides in the VRay render settings, but I believe you have to turn on Indirect Illumination. That's what I'm trying to avoid. I prefer the fact the VRay dome lights help me avoid GI flickering in my animations.

Thanks for all your help!

PerfectLine
09-01-2011, 09:11 PM
Ok, here we go.

------ First off the ADMC settings ------ The anti aliasing engine.

ADMC MIN Subdivs (anti-aliasing sampler) --- Determines the initial (minimum) number of samples taken for each pixel. You will rarely need to set this to more then 1, except if you have very thin lines that are not captured correctly, or fast moving objects if you use motion blur. The actual number of pixels is the square of this number (e.g. 4 subdiivs produce 16 samples per pixel).

ADMC MAX Subdivs (anti-aliasing sampler) -- Determines the maximum number of samples taken for each pixel. The actual maximum number of pixels is the square of this number (e.g. 4 subdiivs produce 16 samples per pixel). NOTE... that vray may take less then the number of samples asked here IF the difference in intensity of the neighboring pixels is small enough.

ADMC Threshold --- The threshold that will be used to determine if a pixel needs more samples. Lower numbers produce more scrutiny. Meaning that the lower the number the more samples it will take until the threshold is met. Hence a lower number is a higher setting.

So 0.01 is a lower quality setting and something like 0.003 is a high quality setting.

------------------ DMC SAMPLER -----------

Adaptive Amount -- Controls the extent to which the number of samples depends on a blurry value. It also controls the minimum number of samples that will be taken. A value of 1.0 is a full adaptation. A Value of 0 is no adaptation being performed.

Default. 0.850. The higher this number is the lower the quality. Lower the number the higher the quality but at cost of time. Often 0.9 works in most cases too. I've taken it down to .7 in extreme cases but could probably have just tuned the shaders and lights slightly better.

Adaptive Threshold -- Controls Vray's judgment of when a blurry value is "good enough" to be used. This directly translates to noise in the result. Smaller values mean less noise, more samples and higher quality. Value of 0.0. means no adaptation will be performed. 0.01 Is a good value here for many instances.

Adaptive Min Samples -- Determines the minimum number of samples that must be made before the early termination algorithm is used. Higher values will slow things down but make the early termination algorithm more reliable. I like a value of 12 here though the default of 8 is a good start for lookdev, moving it up to 12 for finals or higher if your blurry values need more scrutiny.


SubDivs Multi (multiplier) --- This will multiply all subdiv values everywhere during rendering. default 1.0. You can use this to increase or decrease sampling quality everywhere. Kind of a nice quick knob for proxy tests in some cases with larger scenes. 0.5 cuts your subdiv settings in half, etc etc.

This effects everything except for the lightmap, photon map, caustics and the AA subdivs in the ADMC.

Which is.... DoF, motion blur, irradiance map, brute force GI, area lights, area shadows, glossy reflections/refractions are affected by this parameter.


-----------------------------TRY TO REMEMBER THOUGH--------------

1. That you will still want to get your shaders blurry values (reflection/refraction glossiness) set correctly. The farther down from 1.0 glossiness the more samples you'll need.

Glossiness -
1.0 - 8 samples.
.99 to .9 - 16 samples.
.89 to .7 - 24-32 samples.
.650 to 500 - 48 - 64 samples.
lower... etc etc.


2. your light shadows area lights should probably default at 16 samples. depending on size vs scene rendered I've seen as high as 64. But often 16 - 32 is fairly enough in most cases. Just render the light with something to shadow and test render. 24 is a good average final light for most of my lights that are flat area lights. Sphere lights and dome lights need more depending on the situation.

3. DoF and Motion Blur have their own SubDiv settings too. Keep it default for all render lookdev and tests. Then raise them up as needed incrementally until you feel the noise ( or lack thereof) fits the quality you need.

4. GI flickers are their own group of settings (IR, LCache, Brute force). Thankfully GI is rarely seen as noise but rather splotchies when its not set correctly. Make sure you are adjusting the correct parameter when using Vray, though brute force can make addressing noise challenging. Which is why its good to tune the scene before adding GI this way you can trouble shoot each thing, one at a time. I've seen people try to correct GI problems by making the ADMC higher. Which is useless. More AA is not going to smooth the GI solution.

-------------------

I recommend setting up a basic lit scene with clean light and shadow before tuning shaders. Then you can tune shaders and know you are adjusting the noise of the shader before mistaking that the noise you are trying to correct may very well be coming from the light and not the glossiness. Know what is happening where or else you could be adjusting the wrong parameter all day and never solve the problem.

SirRender
09-01-2011, 09:29 PM
Thank you for taking the time to explain. I appreciate you sharing your knowledge. I'm going to start with a clean scene and build up from there.

I was looking at the "Time Depedent" option in the DMC Sampler on spot3d.com

"Time dependent - when this option is Off, the sampling pattern will be the same from frame to frame in an animation. Since this may be undesirable in some cases, you can turn this option On to make the sampling pattern change with time. Note that re-rendering the same frame will produce the same result in both cases."

It seems like it is wise to have it set to On for animations. Do you agree?

Thanks!

PerfectLine
09-01-2011, 09:37 PM
Hey KC. Just wondering if you got a chance to read my last post questions.

"In the spot3d page, they indicate the min samples amount at 5. Are they referring to Adaptive Min Samples in the Settings >> DMC Sampler tab or the Min subdivs in the AA Adpative DMC, where you have both the Min and the Max subdivs?

In the spot3d page I linked the example they are talking about is the min value in the DMC sampler for blurry values... NOT the AA engine.

PerfectLine
09-01-2011, 09:39 PM
I was looking at the "Time Depedent" option in the DMC Sampler on spot3d.com

"Time dependent - when this option is Off, the sampling pattern will be the same from frame to frame in an animation. Since this may be undesirable in some cases, you can turn this option On to make the sampling pattern change with time. Note that re-rendering the same frame will produce the same result in both cases."

It seems like it is wise to have it set to On for animations. Do you agree?

Thanks!

Yes, I leave it on. Always.

jasonhuang1115
09-02-2011, 04:58 AM
Thanks so much, KC. The VRay setting berakdown you shared in the previous is very informative and helpful. I really appreciate it!

- Jason

oracio
09-02-2011, 12:12 PM
Thanks KC for this helpful information!

Do you use the prepass/render animation IMap/LC combo?
I find LC to be so unpredictable that I can't trust it and use it.
especially in petals type materials where you have a translucent, very thin material.
I get artifacts from the Light Cache engine, and I couldn't get rid of them.
Even in a very simple scene where I have one light - the VRay Sun.

Using IMap/BC combo is giving me artifacts-free solution though...

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