colors in blender vs indigo

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Nikolaj Knudsen
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colors in blender vs indigo

Post by Nikolaj Knudsen » Thu Dec 13, 2018 1:17 am

Hi all

What are the "conversion rule"on colors from blender to indigo? Indigo sets the color darker than piked color in blender. Example hex #c0743e turns into #862c0c.
I get that it has to do with compensating for to bright colors/energy in scenes, but difficult when you're trying to color match ncs or ral color palettes for design.

Nik

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Oscar J
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Re: colors in blender vs indigo

Post by Oscar J » Thu Dec 13, 2018 3:09 am

Would also like to know.

Nikolaj Knudsen
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Re: colors in blender vs indigo

Post by Nikolaj Knudsen » Thu Dec 13, 2018 3:45 am

OK- If anyone else can use this.
I made a scene and noted the V value (HSV) from 0-1. This is what I get:
blender_to_indigo.JPG
(greyscale)

FakeShamus
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Re: colors in blender vs indigo

Post by FakeShamus » Thu Dec 13, 2018 7:24 am

doesn't this have to do with Blender's color settings vs the Blendigo export gamma? the color viewing space is editable in Blender's scene tab under color management. But I have also previously edited the Blendigo file to change the the gamma of exported colors (gamma.py, I think...)

Nikolaj Knudsen
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Re: colors in blender vs indigo

Post by Nikolaj Knudsen » Thu Dec 13, 2018 8:59 am

maybe, I will try to look into that :)

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aleksandera
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Re: colors in blender vs indigo

Post by aleksandera » Fri Dec 14, 2018 1:41 am

What are we talking about here? Maybe about this?
The top one is 4.2.21 and the bottom one 4.2.23
The same amount of samples :shock:

Image

https://ibb.co/ZVDf7X2

Nikolaj Knudsen
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Re: colors in blender vs indigo

Post by Nikolaj Knudsen » Sat Dec 15, 2018 12:02 am

I think FakeShamus is right. Blender auto correct hex or hsv colors to sRGB colorspace - I think :) . Anyway, the render result with the darker/altered color from blender is closer to the physical ncs color sample in the final output.

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Zalevskiy
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Re: colors in blender vs indigo

Post by Zalevskiy » Fri Jan 13, 2023 7:56 pm

2023 still not fixed, tested in Blendigo 4.4.1 and Indigo 4.6.0

Blender > Indigo gamma 1.0

Indigo default material scene gamma 2.2


ps this applies only to a simple Diffuse color, when exporting textures, there are gamma settings :!:
Attachments
a2.png
a1.png

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Zalevskiy
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Re: colors in blender vs indigo

Post by Zalevskiy » Fri Jan 13, 2023 10:40 pm

figured out how to get around it

you need to export a material with a texture and gamma 2.2, after 'manually' uncheck ckeckbox a "texture" in the indigo engine environment and then it will be RGB gamma 2.2 ... and if animation is exported, you will have to replace all .igs files through notepad

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Headroom
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Re: colors in blender vs indigo

Post by Headroom » Tue Jan 17, 2023 4:44 am

I am looking through the exporter code to see if this behavior can be changed. In the meantime, would an external material work ?

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Headroom
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Re: colors in blender vs indigo

Post by Headroom » Wed Jan 18, 2023 6:51 am

As an external material the .igm file would look like this:

Code: Select all

<?xml version="1.0" encoding="utf-8"?>
<scenedata>
	<material>
		<name>diffuse_white</name>
		<diffuse>
			<albedo>
				<constant>
					<rgb>
						<rgb>0.8 0.8 0.8</rgb>
						<gamma>2.2</gamma>
					</rgb>
				</constant>
			</albedo>
		</diffuse>
	</material>
</scenedata>

MZ
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Re: colors in blender vs indigo

Post by MZ » Tue Feb 07, 2023 1:35 am

Is this a task specific problem or should colors generally be exported with gamma 2.2?
Doesn't Blender use linear space in colorpickers (except for # codes)?

Edit.
1. Created a sRGB PNG texture texture filled with #AAAAAA color. Blender translated it to 0.66667 value in gamma 2.2.
2. Color picked this texture. Colors look the same, Blender's color picker shows 0.401978

Created two materials (texture and rgb color) and render them next to each other. Seems kinda OK. I'm not sure I understand your problem.
Attachments
color pickers gamma.png

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Zalevskiy
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Re: colors in blender vs indigo

Post by Zalevskiy » Tue Feb 07, 2023 2:40 am

MZ wrote:
Tue Feb 07, 2023 1:35 am
Is this a task specific problem or should colors generally be exported with gamma 2.2?
Doesn't Blender use linear space in colorpickers (except for # codes)?
I don't have a problem anymore, of course, I can manually replace everything in notepad, I'm trying to convey how inexperienced users can see the indigo product from the outside.

Probably, many people who fall into such "traps" cannot find the problem of incorrect data display and are disappointed in indigo, thinking that this is an engine problem. I am sure that indigo is very underestimated, it is difficult to understand it without abstract thinking.

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Zalevskiy
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Re: colors in blender vs indigo

Post by Zalevskiy » Tue Feb 07, 2023 2:59 am

#73CF51 color after export #2B9F14

"Blender use linear space" apparently this is the reason for the color distortion.
Attachments
2023-02-07_005521.jpg
2023-02-07_005339.jpg

MZ
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Re: colors in blender vs indigo

Post by MZ » Tue Feb 07, 2023 5:42 am

One more thing to look out for. Blender treats hex code as a sort of sRGB standard, while in Indigo it is just a 0-255 value representation. So hex in Blender always represents gamma 2.2 corrected color, while in Indigo it is not correlated with gamma.

I see where this is going. Considering future material nodes, I think that standard color sockets should remain in linear space as is color picker and the rest of Blender. However, gamma node can be added, or something like 'color as sRGB' node for less savy users. What do you think?

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