Author Topic: color shift in crop renders?  (Read 246 times)

Offline kentm

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color shift in crop renders?
« on: June 20, 2019, 09:54:36 PM »
Hey folks,

I'm seeing a shift in tone & color when I close crop a render, image attached. I've attached a render test image where I've overlayed a close crop (upper right section) over a fuller render. Between these two renders the only thing that changed was the crop, from a full width half vertical to a tight upper right corner crop. But what I'm seeing in the tighter render is a brighter & bluer tone.

Are some contributing parts of a scene not accounted for when a crop is made?

Thanks,
Kent

90258-0
« Last Edit: June 20, 2019, 10:08:08 PM by kentm »

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #1 on: June 20, 2019, 10:49:21 PM »
This is likely due to your render settings with ray detail region being set to crop.

Offline kentm

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Re: color shift in crop renders?
« Reply #2 on: June 20, 2019, 11:33:40 PM »
Ah, thanks very much.

I'm making a 360 render so I assume that the option I'd want is "360 degree detail (highest)"?

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #3 on: June 21, 2019, 12:03:33 AM »
Ah, thanks very much.

I'm making a 360 render so I assume that the option I'd want is "360 degree detail (highest)"?

For optimum ray quality in 360 degrees, yes. There shouldn't be any difference from a crop to full render with the lighting in the clouds.

Offline kentm

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Re: color shift in crop renders?
« Reply #4 on: June 21, 2019, 12:33:50 AM »
Thanks again!

Online Oshyan

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Re: color shift in crop renders?
« Reply #5 on: June 21, 2019, 07:41:34 PM »
WAS's suggestion may or may not help. Generally Ray Detail is going to affect terrain detail, I believe, whereas your scene is entirely cloud-based from what I can see in the image you posted. So what you're actually probably seeing is a GI-related issue. There are some settings for GI Region Padding which may help you (same place as the Ray Detail settings). But the best way to avoid such issues is to generate a GI cache. Obviously if the scene configuration changes notably, you'd need a new GI cache to represent the lighting properly.

- Oshyan

Offline kentm

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Re: color shift in crop renders?
« Reply #6 on: June 21, 2019, 07:45:10 PM »
thanks!

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #7 on: June 23, 2019, 04:49:11 PM »
WAS's suggestion may or may not help. Generally Ray Detail is going to affect terrain detail, I believe, whereas your scene is entirely cloud-based from what I can see in the image you posted. So what you're actually probably seeing is a GI-related issue. There are some settings for GI Region Padding which may help you (same place as the Ray Detail settings). But the best way to avoid such issues is to generate a GI cache. Obviously if the scene configuration changes notably, you'd need a new GI cache to represent the lighting properly.

- Oshyan

And where is GI Region Padding? There is GI Prepass Padding which makes no change in cloud crop forms lighting. I only know of Ray Detail Region and Ray Detail Region Padding? Is this interestingly a paid feature?

I'd assume that lighting is done through rays (like all software out?), especially with the push to Path Tracing, and it seemed to have been the solution in the past with clouds from what I remember.

Additionally ambient lighting from surfaces, objects, and ambient light bouncing from the object/surfaces will effect a crop cloudform with no terrain present in low lighting.  With crop region rendering a crop of the clouds, you're missing a whole dynamic of shadowing and ambient light blocking and reflection from the surface. In fact, the effect in the crop seems to indicate a lack of terrain and more ambient glow in the clouds.
« Last Edit: June 23, 2019, 05:56:39 PM by WASasquatch »

Online Oshyan

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Re: color shift in crop renders?
« Reply #8 on: June 23, 2019, 07:19:32 PM »
GI Prepass Padding is what I meant, I took the name from memory, should have made sure in the UI before posting. :P

"Ambient" (you mean bounced? i.e. GI?) lighting from surfaces and objects (and the atmosphere) is all accounted for in the GI cache file, hence the potential need for Prepass Padding if you're doing a crop.

- Oshyan

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #9 on: June 23, 2019, 08:13:48 PM »
GI Prepass Padding is what I meant, I took the name from memory, should have made sure in the UI before posting. :P

"Ambient" (you mean bounced? i.e. GI?) lighting from surfaces and objects (and the atmosphere) is all accounted for in the GI cache file, hence the potential need for Prepass Padding if you're doing a crop.

- Oshyan

Err, so TG is just wasting GI resources off-scene no matter what?

I've always had to go 360 for bounced highlight/ambient lighting from off-screen geometry, for cloud/terrain reflections. Geometry precision makes a huuuge difference in where light is going....

Like having something with a face lit behind the camera, using 360 region will give you better lighting results in the visible terrain in the viewport, which means the same is going to be true for light being cast back up on the clouds. 

Online Oshyan

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Re: color shift in crop renders?
« Reply #10 on: June 23, 2019, 08:19:28 PM »
I don't know where you get the idea that TG is "just wasting GI resources off-scene no matter what". What I was saying is that Ray Detail Region Padding is not what you want to adjust if you're seeing a difference that is likely attributable to GI. The GI Prepass Padding setting adjusts the GI calculation off-screen just like Ray Detail Region adjusts the detail of off-screen geometry calculations for e.g. shadows from off-screen terrain.

- Oshyan

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #11 on: June 23, 2019, 08:23:31 PM »
I don't know where you get the idea that TG is "just wasting GI resources off-scene no matter what". What I was saying is that Ray Detail Region Padding is not what you want to adjust if you're seeing a difference that is likely attributable to GI. The GI Prepass Padding setting adjusts the GI calculation off-screen just like Ray Detail Region adjusts the detail of off-screen geometry calculations for e.g. shadows from off-screen terrain.

- Oshyan

You said those things are accounted for, is why? Despite crop regions?

Again, the quality of geometry off-screen will influence where light goes.

Also maybe that setting should be a drop down much like crop region because there isn't much documentation and what is 1, what is 1.25, 2, 0? For such a workflow issue it seems hardly appropriate to hinder that workflow further with a integer.

In general it looks like the clouds are lit by more ambient light like atmosphere haze from cropping to atmosphere and clouds only.
« Last Edit: June 23, 2019, 08:25:17 PM by WASasquatch »

Online Oshyan

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Re: color shift in crop renders?
« Reply #12 on: June 23, 2019, 08:31:23 PM »
Perhaps I didn't communicate clearly, what you're stating isn't what I intended to mean. By saying it was "accounted for in" I did not mean "it is at all times accounting for all of it regardless of settings". I did not say "despite crop regions", for example, so that interpretation is rather an over-reach of my statement I think. After all, why would the GI Prepass Padding setting exist otherwise?

The Region Padding settings are in multiples of the width/height of the view. This is described on the relevant documentation page: https://planetside.co.uk/wiki/index.php?title=Render_-_Advanced_Tab
"The value is typically between 0 and 1 and it controls the amount of padding. 0 means no padding. 1 adds a border around that area which is the same as the width or height of the area. This will make the ray detail region 3 times as wide and 3 times as tall (as seen from the camera)."

- Oshyan

Offline WASasquatch

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Re: color shift in crop renders?
« Reply #13 on: June 23, 2019, 08:40:51 PM »
Perhaps I didn't communicate clearly, what you're stating isn't what I intended to mean. By saying it was "accounted for in" I did not mean "it is at all times accounting for all of it regardless of settings". I did not say "despite crop regions", for example, so that interpretation is rather an over-reach of my statement I think. After all, why would the GI Prepass Padding setting exist otherwise?

The Region Padding settings are in multiples of the width/height of the view. This is described on the relevant documentation page: https://planetside.co.uk/wiki/index.php?title=Render_-_Advanced_Tab
"The value is typically between 0 and 1 and it controls the amount of padding. 0 means no padding. 1 adds a border around that area which is the same as the width or height of the area. This will make the ray detail region 3 times as wide and 3 times as tall (as seen from the camera)."

- Oshyan

I'm not sure how it's even a slight reach at all... For your interpretation I guess it could have, but I was specifically talking about lighting between crop regions and effects from surrounding terrain, objects, etc, and you reply
Quote from: Oshyan
"Ambient" (you mean bounced? i.e. GI?) lighting from surfaces and objects (and the atmosphere) is all accounted for in the GI cache file, hence the potential need for Prepass Padding if you're doing a crop.
The way that ties in seems to indicate GI accounts for all this in the scene regardless of the crop regions I am specifically talking about and their influences.

So the range is 0-1 with a maximum of 3x viewport? Alright. It's not explicitly described at all, on the wiki leaving you with "0.1 might be a good starting point." as the only end-user input besides comparing it to ray detail padding and it effecting crop borders

I'd probably add a circumstances (like these) where it particularly helps to help distinguish it's use, as well as it's range and effect.

« Last Edit: June 23, 2019, 08:51:51 PM by WASasquatch »

Offline Matt

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Re: color shift in crop renders?
« Reply #14 on: June 23, 2019, 11:09:24 PM »
In 4.4 and above, “ray detail region” and “ray detail padding” should not affect cloud lighting at all, but may have some effect in earlier versions. But it’s almost a moot point because you cannot solve the OP’s issue this way. Arguing about it is diverting attention away from the real solution which is either to increase “GI prepass padding” OR to generate a GI cache file with a non-cropped image. The latter will give the best results. Simply increasing GI prepass padding may not always be enough to fix it if the GI quality isn’t high enough.
« Last Edit: June 23, 2019, 11:11:16 PM by Matt »
Just because milk is white doesn't mean that clouds are made of milk.