LINEAR WORKFLOW for the Cinema 4d + Photoshop Artist (Definitive Help Guide 2019)
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Hello guys, so I really considered what would be the best possible topic that could be of interest to the community as a whole and in the same time give me the needed help because my CG career hasn't even started and I am hitting a brick wall. That wall is the implementation of: Linear Workflow and the many hurdles of color management that accompany it...
This is probably helpful for both people of other software like Blender, Maya, Max and other 3d app users trying to figure their way into linear workflow. Let me start by writing what I know and express my current knowledge and then maybe your guys can help me get a better idea on the topic: let me be frank the content will be very, very complex so I hope someone will be able to clarify.
To resume my quest to understanding Linear Workflow:
I watched a like a hundred videos, tutorials, help guides, photo editing, pipelines, et cetera... Sadly though, I came to the realization that the topic is so complex that it would require very professional help to get a definite answer. The ideas in linear workflow and appropriate color management, in combination with 3d apps, rendering and compositing in Photoshop is simply to say: an utter pain unless you're gifted and of pure intelligence or spent a lifetime beating at the topic.
So here we go: (if you see a mistake, call it out! I will appreciate a lot) :
- - - - - - - - - - - - - - - - - - - -
Before we start the exporting of a Render in Cinema 4d: (make sure you have factory settings, Linear Workflow is on, Input Profile:set to RGB.)
This is my first issue, as the help files by Maxon are not well written and don't give an in depth take on why not to use the Input Profile: set to Linear. By looking on forums I got the answer that this equalizes the look of colors in the material editor to a linear render and gives you practically the same result as sRGB, supposdely it's also a big mistake, and I don't know why. But empirically when I rendered it gave me a different result with lighter colors so maybe the answer I found was wrong or I am getting something wrong. Maybe it's just adjusting the baseline for the HSV, I have no idea: HELP!
(please quote this for reference)
- - - - - - - - - - - - - - - - - - - - - -
The first stages of linear workflow:
- 1. 3D apps do linear workflow by default, however your monitor works in sRGB. Yet even though you cannot see all the Linear Values, working in Linear Workflow on an sRGB monitor gives better results than not working in Linear Workflow, so apps like C4D have it as a default, and even if your monitor isn't calibrated linear workflow gives better results for renders. PS: It's good to calibrate your monitor!
- 2. Even so: textures and some other settings require a bit of tweaking in order for "the whole operation to be linear" some of them might even confuse you like Cinema 4d's input profile mentioned above, but forget that; For instance 32bit data is Linear, so if you use 32bit Openexr or Radiance or HDR containers: chances are you are doing it linearly already! However, TIFF, TARGA, JPG, PNGees might require you to tweak the texture into a 32bit version of the file, meaning you will likely go to Photoshop and switch to 32 bit, thus changing the container of the file into a PSD, and tweaking the gamma. Or at the very least you will want to linearize the gamma to a 1.0 gamma by applying a 0.4545 Filter operation to your 2.2 gamma image/texture that has a non-32bit state, (TARGA, TIFF, JPG, PNG, etc= 8, 16 bit), thus making it 1.0 linear.
-3. Finally your render settings might require a color mapping operation where you reset the gamma to 2.2 in order for the lighting to be equalized and to avoid lights burning the image in your render. Then again this completely varies whether you use Octane, Redshift or the native Physical/Standard renderers, the latter two tend to see benefits from color mapping/tone mapping.
- 4. Under the Picture Viewer, provided you saved your image in 32BIT you will see that the image you rendered has a linear profile in Photoshop. To check on this you go to Save As, and a color management option should say ICC Profile: Linear Color Space. so importing it in Photoshop should be such. If you exported to a format below 32bit, such as 8 or 16 bit: chances are your linear workflow stopped before you entered Photoshop.
- - - - - - - - - - - - - - - - - - - - - - -
Notice how so far my logic is somewhat holding its own, I am satisfied of that, but this is where the mess starts:
-13. In any case this interlude was a fun way to vent out certain external frustrations within a CGlearner's mindset....
Then remains linearization of textures:
- 14. Should you always linearize textures? Yes, apparently.
What if the results are good even without that? Then enjoy a caffé latté.
Will you get banding/other visual artifacts? Probably.
Do you know the best way about that?: No, I don't.
- 15. As a last sidenote, ultimately, before uploading to your Artstation or CGsociety portfolio, you will want to convert your files to 8bit-sRGB to get the expected "internet browser" color results. So the image should be tagged. However if your goal is to use your linear image/images for a sequence of a composite. Then the linear workflow continues onward and goes into Adobe After FX/Nuke/Fusion/Resolve. I'm not qualified to express much about that. However this involves keeping the file at its highest possible setting, meaning linear. So you will have to learn even more conventions for those. I believe the complexity there is in the Compositing/Blending Modes. I saw a video by Andrey Lebrov on this. Speaking of, he was kind of the reason why I went to write this, as I was inspired to have my more amateur take on his ideas. Hopefully I did not put shame on that. Anyways.....
- - - - - - - - - - - - - - - - - - - - -
Please feel free to add to this discussion or criticize, note that I might edit this post as I want to help others who are stuck like me in this horrible linear problem. Thank you in advance for those who participate in the discussion!!! x)
This is probably helpful for both people of other software like Blender, Maya, Max and other 3d app users trying to figure their way into linear workflow. Let me start by writing what I know and express my current knowledge and then maybe your guys can help me get a better idea on the topic: let me be frank the content will be very, very complex so I hope someone will be able to clarify.
To resume my quest to understanding Linear Workflow:
I watched a like a hundred videos, tutorials, help guides, photo editing, pipelines, et cetera... Sadly though, I came to the realization that the topic is so complex that it would require very professional help to get a definite answer. The ideas in linear workflow and appropriate color management, in combination with 3d apps, rendering and compositing in Photoshop is simply to say: an utter pain unless you're gifted and of pure intelligence or spent a lifetime beating at the topic.
So here we go: (if you see a mistake, call it out! I will appreciate a lot) :
- - - - - - - - - - - - - - - - - - - -
Before we start the exporting of a Render in Cinema 4d: (make sure you have factory settings, Linear Workflow is on, Input Profile:set to RGB.)
This is my first issue, as the help files by Maxon are not well written and don't give an in depth take on why not to use the Input Profile: set to Linear. By looking on forums I got the answer that this equalizes the look of colors in the material editor to a linear render and gives you practically the same result as sRGB, supposdely it's also a big mistake, and I don't know why. But empirically when I rendered it gave me a different result with lighter colors so maybe the answer I found was wrong or I am getting something wrong. Maybe it's just adjusting the baseline for the HSV, I have no idea: HELP!
(please quote this for reference)- - - - - - - - - - - - - - - - - - - - - -
The first stages of linear workflow:
- 1. 3D apps do linear workflow by default, however your monitor works in sRGB. Yet even though you cannot see all the Linear Values, working in Linear Workflow on an sRGB monitor gives better results than not working in Linear Workflow, so apps like C4D have it as a default, and even if your monitor isn't calibrated linear workflow gives better results for renders. PS: It's good to calibrate your monitor!
- 2. Even so: textures and some other settings require a bit of tweaking in order for "the whole operation to be linear" some of them might even confuse you like Cinema 4d's input profile mentioned above, but forget that; For instance 32bit data is Linear, so if you use 32bit Openexr or Radiance or HDR containers: chances are you are doing it linearly already! However, TIFF, TARGA, JPG, PNGees might require you to tweak the texture into a 32bit version of the file, meaning you will likely go to Photoshop and switch to 32 bit, thus changing the container of the file into a PSD, and tweaking the gamma. Or at the very least you will want to linearize the gamma to a 1.0 gamma by applying a 0.4545 Filter operation to your 2.2 gamma image/texture that has a non-32bit state, (TARGA, TIFF, JPG, PNG, etc= 8, 16 bit), thus making it 1.0 linear.
-3. Finally your render settings might require a color mapping operation where you reset the gamma to 2.2 in order for the lighting to be equalized and to avoid lights burning the image in your render. Then again this completely varies whether you use Octane, Redshift or the native Physical/Standard renderers, the latter two tend to see benefits from color mapping/tone mapping.
- 4. Under the Picture Viewer, provided you saved your image in 32BIT you will see that the image you rendered has a linear profile in Photoshop. To check on this you go to Save As, and a color management option should say ICC Profile: Linear Color Space. so importing it in Photoshop should be such. If you exported to a format below 32bit, such as 8 or 16 bit: chances are your linear workflow stopped before you entered Photoshop.
- - - - - - - - - - - - - - - - - - - - - - -
Notice how so far my logic is somewhat holding its own, I am satisfied of that, but this is where the mess starts:
- 5. Welcome to Photoshop! Now that you thought you knew what you were doing, here comes the part where you will start reading a hundred more topics to try to make sense only to confuse you more. As you may learn soon: Photoshop has a very big color management method divided into more or less 4-5 screen tabs/areas/sub areas hidden within the context menu of the software. So here is the best hint I got so far:
- 6. UNLESS YOU KNOW WHAT YOU'RE DOING: DON'T TWEAK THE COLOR MANAGEMENT PROFILES! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Way to start your CG career, a nice brick wall. In any case we try to work at it still. So here is where the linear workflow logic actually needs implementation. There is also implementation needs in software like After Effects and Nuke, Fusion, Resolve. Premiere Pro is a bit shy here, but still competing... More on the video side though....
- 7. So Photoshop huh? Huge topic... Huge.... You have a setting under:
View > Proof Setup. That defines the way the software applies its chrominance/luminance mapping aka the baseline ICC you would like the software to emulate. This is the base color setting you will see in your software and it will pretty much be your first hurdle. If you select photoshop while closed as an APP, while holding ALT SHIFT and CTRL then right click and open, you will be offered to set Photoshop to factory settings. Under factory settings:
The proof setup is as follows: Working CMYK, proof colors is unchecked. I have absolutely no idea why it is like this, since Cmyk is a print format, it makes absolutely no sense to me. And this is a key visual parameter of the software. Whereas you have more logical modes like 2.2sRGB which makes much more sense to be default, or Monitor RGB. Which should more or less be the same. I really don't understand this part, I've been thinking at it for weeks. Setting to Internet sRGB or Monitor gives horrendous dark/unsightly results. My mind is stuck with this sentence: "How in god's name is CMYK Linear, !@#(^&%!" Pretty much. Adobe has some explanations to make there....
For 32bit Proof Colors will be active by default, and for 8 and 16 it will not be.
- 8. Thought you had it covered? This still means nothing; it's just what appears in your previews, not what the file carries. Here appear the next 3 hurdles:
- Color Settings
- Assign Profile
- Convert to Profile
- 9. Color settings is the place where you define the base color settings for the document and all read documents in Photoshop. Unless your file is "tagged" meaning it has an "ASSIGNED COLOR PROFILE/A.K.A. TAGGED FILE" wink wink. The base color for the document are called "Working Space" by default for Photoshop it should be sRGB; .... but since your rendered a "TAGGED= LINEAR" file in 32bit in your Cinema4D render this will not matter. AS TAGGED FILES DO NOT INHERIT THE WORKING SPACE PROPERTIES! YES! Hurdle Crossed!
- 10. Assign Profile will assign a color profile to your file. Since you have a Linear Render from Photoshop, this will actually hurt the look of your 32 bit file. This is like the worst thing you can do right now on a 32bit file. Since Linear is one of the greatest color spaces to work for Renders. The only meaning I would see to this is if someone were trying to switch to proPhoto for some photo needs or to ACES for a Hollywood Blockbuster. I have no idea about the conventions for those formats however since it's not my work goal to be a pro photographer, and chances to go to Hollywood are slim if null for me.
- 11. In any case next we have Convert to profile. For a 32bit file, this will not be available. I have no idea why, don't ask me. Maybe this implies all 32bit files have the same "linear nature" or whatever. But..... For the same 8bit copy Render of my file this works. And does pretty much the same as Assign Profile except it keeps the look of the TAGGED image: the same. Meaning you won't see a visual difference, but the profile will be changed. This might have to do with compatibility or trying to convert a file for some app to read it correctly, however visually as part of your workflow it may see useless. Someone might have a better explanation behind its usage. I don't.
- 6. UNLESS YOU KNOW WHAT YOU'RE DOING: DON'T TWEAK THE COLOR MANAGEMENT PROFILES! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Way to start your CG career, a nice brick wall. In any case we try to work at it still. So here is where the linear workflow logic actually needs implementation. There is also implementation needs in software like After Effects and Nuke, Fusion, Resolve. Premiere Pro is a bit shy here, but still competing... More on the video side though....
- 7. So Photoshop huh? Huge topic... Huge.... You have a setting under:
View > Proof Setup. That defines the way the software applies its chrominance/luminance mapping aka the baseline ICC you would like the software to emulate. This is the base color setting you will see in your software and it will pretty much be your first hurdle. If you select photoshop while closed as an APP, while holding ALT SHIFT and CTRL then right click and open, you will be offered to set Photoshop to factory settings. Under factory settings:
The proof setup is as follows: Working CMYK, proof colors is unchecked. I have absolutely no idea why it is like this, since Cmyk is a print format, it makes absolutely no sense to me. And this is a key visual parameter of the software. Whereas you have more logical modes like 2.2sRGB which makes much more sense to be default, or Monitor RGB. Which should more or less be the same. I really don't understand this part, I've been thinking at it for weeks. Setting to Internet sRGB or Monitor gives horrendous dark/unsightly results. My mind is stuck with this sentence: "How in god's name is CMYK Linear, !@#(^&%!" Pretty much. Adobe has some explanations to make there....
For 32bit Proof Colors will be active by default, and for 8 and 16 it will not be.
- 8. Thought you had it covered? This still means nothing; it's just what appears in your previews, not what the file carries. Here appear the next 3 hurdles:
- Color Settings
- Assign Profile
- Convert to Profile
- 9. Color settings is the place where you define the base color settings for the document and all read documents in Photoshop. Unless your file is "tagged" meaning it has an "ASSIGNED COLOR PROFILE/A.K.A. TAGGED FILE" wink wink. The base color for the document are called "Working Space" by default for Photoshop it should be sRGB; .... but since your rendered a "TAGGED= LINEAR" file in 32bit in your Cinema4D render this will not matter. AS TAGGED FILES DO NOT INHERIT THE WORKING SPACE PROPERTIES! YES! Hurdle Crossed!
- 10. Assign Profile will assign a color profile to your file. Since you have a Linear Render from Photoshop, this will actually hurt the look of your 32 bit file. This is like the worst thing you can do right now on a 32bit file. Since Linear is one of the greatest color spaces to work for Renders. The only meaning I would see to this is if someone were trying to switch to proPhoto for some photo needs or to ACES for a Hollywood Blockbuster. I have no idea about the conventions for those formats however since it's not my work goal to be a pro photographer, and chances to go to Hollywood are slim if null for me.
- 11. In any case next we have Convert to profile. For a 32bit file, this will not be available. I have no idea why, don't ask me. Maybe this implies all 32bit files have the same "linear nature" or whatever. But..... For the same 8bit copy Render of my file this works. And does pretty much the same as Assign Profile except it keeps the look of the TAGGED image: the same. Meaning you won't see a visual difference, but the profile will be changed. This might have to do with compatibility or trying to convert a file for some app to read it correctly, however visually as part of your workflow it may see useless. Someone might have a better explanation behind its usage. I don't.
- - - - - - - - - - - - - - - - - - - - - - -
- 12. This now seems like the end of the hardest part but here is where your mind starts playing tricks on you:
..... is this the actual proper way to work?
- 12. This now seems like the end of the hardest part but here is where your mind starts playing tricks on you:
..... is this the actual proper way to work?
...... how does this relate to a multipass workflow involving light modes?
...... I read somewhere you're supposed to Linear Dodge (add) channels together... does working under certain proof settings restrict this?
..... does my screen have to be wider gamut?
..... is there a reason for that new mac 10bit depth screen?
..... if Arri/RED cameras can film superior bit depths like 12bit, 14bit, how does this integrate into Linear workflow?
...... I read somewhere you're supposed to Linear Dodge (add) channels together... does working under certain proof settings restrict this?
..... does my screen have to be wider gamut?
..... is there a reason for that new mac 10bit depth screen?
..... if Arri/RED cameras can film superior bit depths like 12bit, 14bit, how does this integrate into Linear workflow?
..... is the ultimate skill the capacity to blend film with linear rendering to get visual effects that will impress moviegoers?
..... why the hell do people use Proof Setup then if you can get visually appealing results without it and still keep your files linear?
..... how many sugar cubes does it take to pile up to reach the moon?
- - - - - - - - - - - - - - - - - - - - - -
..... why the hell do people use Proof Setup then if you can get visually appealing results without it and still keep your files linear?
..... how many sugar cubes does it take to pile up to reach the moon?
- - - - - - - - - - - - - - - - - - - - - -
Then remains linearization of textures:
....Is editing the gamma enough?
....how do you know that applying a gamma filter of 0.4545/ ratio to your texture will make it linear? What if it looks ugly, should you tweak it? (yes you should)
- 14. Should you always linearize textures? Yes, apparently.
What if the results are good even without that? Then enjoy a caffé latté.
Will you get banding/other visual artifacts? Probably.
Do you know the best way about that?: No, I don't.
- 15. As a last sidenote, ultimately, before uploading to your Artstation or CGsociety portfolio, you will want to convert your files to 8bit-sRGB to get the expected "internet browser" color results. So the image should be tagged. However if your goal is to use your linear image/images for a sequence of a composite. Then the linear workflow continues onward and goes into Adobe After FX/Nuke/Fusion/Resolve. I'm not qualified to express much about that. However this involves keeping the file at its highest possible setting, meaning linear. So you will have to learn even more conventions for those. I believe the complexity there is in the Compositing/Blending Modes. I saw a video by Andrey Lebrov on this. Speaking of, he was kind of the reason why I went to write this, as I was inspired to have my more amateur take on his ideas. Hopefully I did not put shame on that. Anyways.....
- - - - - - - - - - - - - - - - - - - - -
Please feel free to add to this discussion or criticize, note that I might edit this post as I want to help others who are stuck like me in this horrible linear problem. Thank you in advance for those who participate in the discussion!!! x)
Replies
Im probably one out of 5 cinema users here, C4D community is more on other forums like C4D café and such
What exactly is the mission statement, Im a bit confused, what is the goal to be achieved?
I am planning on adding pictures to the post so that every stage and every confusion that will ever haunt an sRGB 3d artist trying to get into a true linear workflow gets simplified and answered. Since most videos and tutorials on the net seem to have self-contained s ideas, that assume the viewer has the "inside information" required to figure out what is implied.
Most times for things involving computers the meaning behind why each thing is done needs to be explained every stage/layer of the way to grasp the idea perfectly. Otherwise you always get the question "why/how come" in your mind.
So in the same time I try to learn the most minute intricacies about linear workflow, and hopefully share some insight for those struggling to learn about it. That would be the idea of why I wrote this topic and hopefully some more people will join in.
Textures to use within cinema? Within games? Artwork renders to upload online?
What is the issue to be improved on?
My general idea involves situations when you have numerous layers and having the exact procedure to get a proper linear composite. That's one hurdle that led me to write all of this. I mean when you get issues here with blending rules etc, and how to properly blend and still keep the gamma at 1.0. Then also to worry about the color profile conventions, and eventually to have a definite rule as to how the process is best done.
For web, If my goal was to have it sit on the web then it would be an sRGB file in the end due to color conventions for the large pool of devices that work in that color profile.
Linear renders so far I would say that most people would like to have correct lighting for their portfolio pieces. Otherwise I assume in production the meaning would depend on what's being asked. I suppose the texture artist will have issues if say a texture set for Unreal Engine is not properly gamma-ed, but that's one side of the story, so I wouldn't particularly emphasize gaming or film, but more in general. Of course if you would like to give your take on linear workflows, I would love to hear. How would you explain the process?