Author Topic: 1.6.2 reflections  (Read 3745 times)

2017-07-27, 16:15:07

Jpjapers

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Hi Guys,

Not sure if this should be in bugs or not, im just asking the question really.
It seems that in 1.6.2, the reflections in glass etc are so much noisier than they previously were. I have a render at a tiny 1280x720, its currently on 691 passes and whilst alot of my render is totally clean, the reflections in the windows are as noisy as they were after about 10 passes. I understand you rolled some of 1.7 development into the 1.6.2 patch, is this due to the adaptivity or something else thats changed or is it just me noticing it only now?

Ive attached 2 small snips from the render, one of an area with alot less noise and then one of the reflections in the windows.

Thanks
Jack

2017-07-27, 16:27:51
Reply #1

maru

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Are you sure this is a 1.6 hf2 issue and that the same thing would not happen in previous versions?
Do you have a scene you could share with us, which shows this?

2017-07-27, 16:28:10
Reply #2

Jpjapers

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For a 1280x720 image with alot of lights at over 1000 passes i would expect that the noise be much MUCH cleaner than it currently is?

2017-07-27, 16:29:25
Reply #3

Jpjapers

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Are you sure this is a 1.6 hf2 issue and that the same thing would not happen in previous versions?
Do you have a scene you could share with us, which shows this?

I used this project with 1.6.1 and whilst it would take much longer to get to the number of passes im on, the noise was much cleaner.
You guys already have this scene, its on the private dropbox as i submitted a mantis log about a crash that kept occurring but thats not happened since 1.6.2

2017-07-27, 17:18:25
Reply #4

Jpjapers

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At 1500 passes the noise level in some areas of the windows is still very high.


2017-07-27, 17:24:21
Reply #5

Ondra

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what is the name of the scene? Can we directly reproduce it from the scene you sent us? (what camera, frame time, ...)?
Rendering is magic.
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2017-07-27, 17:41:39
Reply #6

maru

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I just tried reproducing this in a simplified scene, but failed. It must be something different.
I would have to take a look at the scene.

By the way jpjapers you can change the sampler to the 1.6 hf1 "stratified" by going to devel/experimental rollout:
https://coronarenderer.freshdesk.com/support/solutions/articles/12000021288
It would be great if you could check if the result is different.

2017-07-28, 09:46:45
Reply #7

Jpjapers

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what is the name of the scene? Can we directly reproduce it from the scene you sent us? (what camera, frame time, ...)?

Ill reupload soon and post the filename.

Quote
I just tried reproducing this in a simplified scene, but failed. It must be something different.
I would have to take a look at the scene.

By the way jpjapers you can change the sampler to the 1.6 hf1 "stratified" by going to devel/experimental rollout:
https://coronarenderer.freshdesk.com/support/solutions/articles/12000021288
It would be great if you could check if the result is different.

Ill certainly give it a go. Is it possible that its due to the amount of lights in my scene? I have probably about 100+
« Last Edit: 2017-07-28, 09:55:12 by jpjapers »

2017-07-28, 11:06:11
Reply #8

Jpjapers

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It seems that changing to stratified has no effect.
It appears that the lights in the 'Rest(Unassigned)' channel are whats causing the problem as its only that channel that doesnt seem to be rendering as well as the others.
Ill try moving the lights onto a lightselect element and see what happens

2017-07-28, 11:24:41
Reply #9

maru

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We've had a slightly similar case in support some time ago, and the solution was to remove an object which has Corona Light mtl applied to it, as it had over 4000 triangles.

It is advised to use as simple light-emitting model as possible (e.g. just a plane, or a Corona Light with shape set to disk, sphere, etc), and a separate geometry for the part of the light which is glowing, but does not cast any light into the scene.

Let's wait for the scene, but my guess is that this will be something similar.

2017-07-28, 11:45:10
Reply #10

Jpjapers

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We've had a slightly similar case in support some time ago, and the solution was to remove an object which has Corona Light mtl applied to it, as it had over 4000 triangles.

It is advised to use as simple light-emitting model as possible (e.g. just a plane, or a Corona Light with shape set to disk, sphere, etc), and a separate geometry for the part of the light which is glowing, but does not cast any light into the scene.

Let's wait for the scene, but my guess is that this will be something similar.

Thats a good point i do have some areas where im using cylinders to emit light. However in the image i posted its all done with IES data.
Is there a quick way to see which lights are unassigned to a lightselect element??

2017-07-28, 15:59:42
Reply #11

maru

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Wait is this persistent noise only appearing in the LightMix element? Or also in regular beauty?

2017-07-31, 10:17:35
Reply #12

Jpjapers

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Wait is this persistent noise only appearing in the LightMix element? Or also in regular beauty?

It appears to only be in the 'unassigned' channel in lightmix

2017-07-31, 11:12:45
Reply #13

maru

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That information was kind of important to understand the whole issue. :)

Do you have some proof that it was different in earlier versions?

Are you also adjusting some LightMix values, or just inspecting the "rest" element?

2017-07-31, 15:24:34
Reply #14

Jpjapers

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That information was kind of important to understand the whole issue. :)

Do you have some proof that it was different in earlier versions?

Are you also adjusting some LightMix values, or just inspecting the "rest" element?

I dont have proof that it was different unfortunately, im not sure if it would vary scene by scene but ive never had problems with glazing before.
Im disabling all the other lightselect elements and the 'rest' channel is the one with all the noise. Is it possible that its to do with my scene setup.
As the building is from revit, it uses 2 panes of glass where there are double glazed windows. Could that be causing issues?

Thanks
Jack

2017-08-02, 10:04:55
Reply #15

tomasz

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@jpjapers Did you use Corona DR to render your scene?

I'm asking, because we have a similar problem with too much noise on glossy elements (interior scene), but it only appears when we a re rendering with DR. Currently we have to use 1.6.2 with devel/experimental mode on and stratified sampler as @maru suggested

2017-08-07, 11:16:31
Reply #16

maru

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We need a proper report here to be able to look into this. The scene itself would be best. Some example images are fine too, comparing old vs new sampler and what is happening. Plus instructions how to reproduce it.

Persistent noise when using LightMix is sometimes expected - for example when strongly increasing or lowering light intensity, but also when disabling some lightselect elements, and that is basically what you are doing when switching to "rest" element only. You disable the contribution of other lights, so noise-free image is not expected.

2017-08-10, 20:04:50
Reply #17

Fluss

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I experienced the problem this afternoon. I was rendering an exterior scene with corona sun and sky. One of the building has a highly reflective / metallic coating. Everything was good until I plug an hdri in the reflection override. And then, speckles everywhere on the building. Removing reflection override solved the problem. I'm considering switching back to 1.6.1 as I'm just starting the project and that I have to render a hudge animation on an external render farm. That kind of stuff could cost me a lot and I'm not very confident with this version of the software.

2017-08-10, 20:27:33
Reply #18

romullus

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I don't think that reverting back to 1.6 would help you. Excessive noise from reflection override is long standing bug, you may have to roll back to alpha versions to get rid of it :]

https://corona-renderer.com/bugs/view.php?id=2124
I'm not Corona Team member. Everything i say, is my personal opinion only.

2017-08-10, 20:35:53
Reply #19

Fluss

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Argh that sucks...

Excessive noise from reflection override is long standing bug, you may have to roll back to alpha versions to get rid of it :]

So no solution for this since all this time ? If not, I wonder why the feature is still there as it makes it completly useless.