Why you don't have 1 million Subscribers man, you explain things so so well you spend good amount of money on a Decent mic your voice is super crystal clear and the way you explain a concept is super composed and awesome. I hope people can see the difference between crapy stuff out there on youtube and some Quality stuff on your channel. I search the LUT information on youtube because the last tutorial I watch didn't explain it properly.
Great TUT I'd seen a different one on UT but this was much clearer and straightforward explaining everything so well and not rushing it,so TY so much :) I've never looked at using LUT's but I can see them clearly now as a extra option.
The Color Neutral LUT image (now a webp format) from the UE4 tutorial has gone through image compression, and this affects color grading accuracy. I recommend exporting a CUBE file for the neural LUT (not applying any adjustment players) from photoshop and convert that to the correct CLUT image using this tool github.com/dvjvp/LUT-to-UE4-clut.
How to do the Opposite. I already have the scene in unreal with post process applied but now I want Unreal's PPV data out as LUT for other software like maybe substance painter.
Ryan, thank you so much for this tutorial! BTW, which way you'd use to control different LUT dynamically, let's say from sunny to rainy look, you know? Thank you in advance :)
Hey Ryan thank you so much for these videos! I've watched all of your lighting ones and each one are very informational. I have a question regarding LUT's here. Let's say I want to imitate a color grading from a movie into my UE4 scene, is there a way to create an LUT from a screenshot of the movie in mind for example? Or would I take a screenshot of my scene, place it beside the movie screenshot, and try to get as close to it as I can? That might have been a little confusing, hope you understand! haha, thank you!!
Thanks for your support Sam! As for creating a LUT from a picture...not directly. You can create a LUT in Photoshop, but as you said...this process is more manual than automatic. A side by side of your scene and the movie reference is honestly the only way to generate a LUT with exact results.
@@ThatRyanManning Had a feeling, sounds good! Thanks again Ryan! Can't wait for the next lighting specific video :) They help tremendously as a new artist.
Thank you, but at 5:31 don't do that. The neutral LUT that Epic provides in their documentation is 8-bit. If you change an 8-bit image to 16-bit, it doesn't magically give you better values for the pixels, in fact, you just make it worse, because the values will be exactly the same but the texture will take up more space than needed. It's like saving an MP3 as FLAC, expecting it to contain that missing data somehow (the data that makes it higher quality), so it obviously won't sound any better by doing that. Or saving a JPG as PNG, thinking that the PNG format magically makes it higher quality, lol. Obviously, don't save your LUT in a compressed format. Goes without saying. But turning it into 16-bit does absolutely nothing. If you look at the "Additional Notes" section, it says that "LUTs happen in Low Dynamic Range (LDR) and on the final image color". That means 8-bit. And speaking of compression, maybe don't leave it as "Default". That's probably where your differences come from - well, that, and the fact that it's storing 16 values (as pixels) for each x,y,z dimension of that LUT, as a "color cube" (kind of), instead of 256 values for each dimension, so the data is interpolated, meaning the color differences between those 16 values are _inferred,_ not actual data that is being read. That interpolation helps with performance, since it's faster to sample from a smaller texture (256x16px), which gives it a better cache locality, than to sample from a full 4090x256 texture (16 * 256 for the x, and 16 * 16 for the y). That would give you the full accuracy, but the trade-off in performance is not really worth it, perceptually speaking.
3:50 Don't do that! Omg... DOES THAT LOOK TO YOU LIKE A 256x16 IMAGE?? It should be hella tiny on that 8k screen of yours. Read the article. It says there, after step #5: _"LUT Texture Example - right-click and _*_Save as_*_ "_ That's the image you should be using. Omg... 🤣 I think it's Epic's fault, too. For not providing the link EARLIER in the article. They assumed people will read it. But even if they read it once, coming back to it 3 weeks later, or "next project" later they will forget, and probably use that .webp image or whatever. LMAO.
From the official documentation: A Lookup Table (LUT) can be used to achieve color correction using a Post Process Volume. Instead of using three one-dimensional (1D) lookup tables, a single three-dimensional (3D) Lookup Table is used. This offers more sophisticated color transformation, which can be used for something like desaturation.
Ryan Manning yes, but a LUT is a vector field, not a scalar field. You can’t visualize it like other channels. That thing he downloaded isn’t actually the lut.
It encodes the representation of the 3DLUT in RGB space. As Unreal already *knows* the original format, it is able to easily extract the delta and interpolate across the values to determine the "actual" 3D Lut.
It kind of is. Let me try to explain. So you have a 256x16px texture. Each "square" (let's call them _slices),_ contains 16px for the .x and 16px for the .y. Those are the Red and Green channels. If you open up this 256x16px LUT in Photoshop and look at the RGB channels, you'll see the Red channel as a grayscale _gradient_ for each slice. And the Green channel as a gradient from top to bottom - which is still 16 "slices", but just _looks_ like one continuous gradient because they all point in the same direction. The .z values are encoded in the Blue channel of the texture. Which is still a gradient, still 16 "slices", just with a larger resolution. In the end, these slices make up a "color cube". Imagine a cube that has the "0,0,0" origin in one of the corners, and on each "axis" of this cube there's a gradient that reaches the other edge of the cube. And that is exactly what a color channel is - a gradient. With 256 shades of gray on all 3 channels, you get ~16 mil colors (because it's 256*256*256). But you can make due with 16 shades of gray for something like this, and interpolate the values between them in a shader. So for all intents and purposes, it IS a 3D image. Just with a different way of visualizing it. Not to be confused with 3D like at the cinema where they give you polarized glasses to be able to "isolate" each overlayed frame for each eye for a "3D" effect. 😅 That's a different thing.
Why you don't have 1 million Subscribers man, you explain things so so well you spend good amount of money on a Decent mic your voice is super crystal clear and the way you explain a concept is super composed and awesome. I hope people can see the difference between crapy stuff out there on youtube and some Quality stuff on your channel. I search the LUT information on youtube because the last tutorial I watch didn't explain it properly.
That was an awesome tutorial. I knew roughly what LUTs were doing but had no idea how to customise them. Thank you.
Nice. As a person who uses Octane and Redshift, LUT's are king to make an image sing. Now I know how to use it in EU thanks to you.
Amazing tutorial, quick and straight forward. Subscribed!
Great TUT I'd seen a different one on UT but this was much clearer and straightforward explaining everything so well and not rushing it,so TY so much :) I've never looked at using LUT's but I can see them clearly now as a extra option.
Stellar as always Ryan, thanks for sharing!
thanks Ryan, never knew about them.. quite impressive feature, and as usuall, well presented by you.
Thanks for all of these. Really appreciated.
Loved the video! Super helpful. You must have a 40in monitor because that is some tiny fonts!
Great tutorial!
very helpful, thanks Ryan
Thanks, this was very helpful!
Nice one man. Thank you
The Color Neutral LUT image (now a webp format) from the UE4 tutorial has gone through image compression, and this affects color grading accuracy. I recommend exporting a CUBE file for the neural LUT (not applying any adjustment players) from photoshop and convert that to the correct CLUT image using this tool github.com/dvjvp/LUT-to-UE4-clut.
If you read the article after step #5 it says: _"LUT Texture Example - right-click and _*_Save as_*_ "_
That's the image you should be using.
How to do the Opposite. I already have the scene in unreal with post process applied but now I want Unreal's PPV data out as LUT for other software like maybe substance painter.
You can't.
Not all software use the same post-processing parameters.
Ryan, thank you so much for this tutorial! BTW, which way you'd use to control different LUT dynamically, let's say from sunny to rainy look, you know? Thank you in advance :)
voce e o melhor
thanks!
Hey Ryan thank you so much for these videos! I've watched all of your lighting ones and each one are very informational. I have a question regarding LUT's here. Let's say I want to imitate a color grading from a movie into my UE4 scene, is there a way to create an LUT from a screenshot of the movie in mind for example? Or would I take a screenshot of my scene, place it beside the movie screenshot, and try to get as close to it as I can? That might have been a little confusing, hope you understand! haha, thank you!!
Thanks for your support Sam! As for creating a LUT from a picture...not directly. You can create a LUT in Photoshop, but as you said...this process is more manual than automatic. A side by side of your scene and the movie reference is honestly the only way to generate a LUT with exact results.
@@ThatRyanManning Had a feeling, sounds good! Thanks again Ryan! Can't wait for the next lighting specific video :) They help tremendously as a new artist.
so this is how it feels when u play 4k video in 720p monitor hahahaha. can barely see it in 1080p
Very strange technique.. In Photoshop you can adjust just gray color, and all scene balanced..
Or can make color balance
Thank you, but at 5:31 don't do that. The neutral LUT that Epic provides in their documentation is 8-bit.
If you change an 8-bit image to 16-bit, it doesn't magically give you better values for the pixels, in fact, you just make it worse, because the values will be exactly the same but the texture will take up more space than needed.
It's like saving an MP3 as FLAC, expecting it to contain that missing data somehow (the data that makes it higher quality), so it obviously won't sound any better by doing that. Or saving a JPG as PNG, thinking that the PNG format magically makes it higher quality, lol.
Obviously, don't save your LUT in a compressed format. Goes without saying. But turning it into 16-bit does absolutely nothing.
If you look at the "Additional Notes" section, it says that "LUTs happen in Low Dynamic Range (LDR) and on the final image color". That means 8-bit.
And speaking of compression, maybe don't leave it as "Default". That's probably where your differences come from - well, that, and the fact that it's storing 16 values (as pixels) for each x,y,z dimension of that LUT, as a "color cube" (kind of), instead of 256 values for each dimension, so the data is interpolated, meaning the color differences between those 16 values are _inferred,_ not actual data that is being read. That interpolation helps with performance, since it's faster to sample from a smaller texture (256x16px), which gives it a better cache locality, than to sample from a full 4090x256 texture (16 * 256 for the x, and 16 * 16 for the y). That would give you the full accuracy, but the trade-off in performance is not really worth it, perceptually speaking.
3:50 Don't do that! Omg... DOES THAT LOOK TO YOU LIKE A 256x16 IMAGE?? It should be hella tiny on that 8k screen of yours.
Read the article. It says there, after step #5: _"LUT Texture Example - right-click and _*_Save as_*_ "_
That's the image you should be using.
Omg... 🤣 I think it's Epic's fault, too. For not providing the link EARLIER in the article. They assumed people will read it. But even if they read it once, coming back to it 3 weeks later, or "next project" later they will forget, and probably use that .webp image or whatever. LMAO.
A lut is absolutely not a 3d image
From the official documentation: A Lookup Table (LUT) can be used to achieve color correction using a Post Process Volume. Instead of using three one-dimensional (1D) lookup tables, a single three-dimensional (3D) Lookup Table is used. This offers more sophisticated color transformation, which can be used for something like desaturation.
Ryan Manning yes, but a LUT is a vector field, not a scalar field. You can’t visualize it like other channels. That thing he downloaded isn’t actually the lut.
It encodes the representation of the 3DLUT in RGB space. As Unreal already *knows* the original format, it is able to easily extract the delta and interpolate across the values to determine the "actual" 3D Lut.
It kind of is.
Let me try to explain.
So you have a 256x16px texture.
Each "square" (let's call them _slices),_ contains 16px for the .x and 16px for the .y. Those are the Red and Green channels.
If you open up this 256x16px LUT in Photoshop and look at the RGB channels, you'll see the Red channel as a grayscale _gradient_ for each slice. And the Green channel as a gradient from top to bottom - which is still 16 "slices", but just _looks_ like one continuous gradient because they all point in the same direction.
The .z values are encoded in the Blue channel of the texture. Which is still a gradient, still 16 "slices", just with a larger resolution.
In the end, these slices make up a "color cube". Imagine a cube that has the "0,0,0" origin in one of the corners, and on each "axis" of this cube there's a gradient that reaches the other edge of the cube.
And that is exactly what a color channel is - a gradient. With 256 shades of gray on all 3 channels, you get ~16 mil colors (because it's 256*256*256). But you can make due with 16 shades of gray for something like this, and interpolate the values between them in a shader.
So for all intents and purposes, it IS a 3D image. Just with a different way of visualizing it. Not to be confused with 3D like at the cinema where they give you polarized glasses to be able to "isolate" each overlayed frame for each eye for a "3D" effect. 😅 That's a different thing.