Blender 4.2! New tone mapping, the Khronos PBR Neutral Tone Mapper.

product visualization is a quite common use for 3D applications like blender where products with specific colors need to be produced blender 4.2 has a new render feature that aims to improve tone mapping for these situations where the matching accuracy to predefined srgb product colors is important the Kronos PBR neutral tone mapper is designed to do this under neutral lighting conditions hence the name phone mapping is the process of fitting bright out of range colors back into the limits of a display device or common image format such as a JPEG image in a perceptually pleasing way when blender 4.0 came out a new tone mapping system called agx was put in place to help solve some of the limitations with the older filmic tone mapper for instance agx helped to solve filmx six colors problem but agx also introduced its own issues that some people haven't been entirely happy about if you watched my video on agx you'll recall that we spoke about some Imaging Concepts color spaces High dynamic range light intensities and closed domain color ranges in order to understand what both filmi and agx were doing understanding these Concepts will give you an appreciation for what the new Kronos neutral tone mapper accomplished es let's quickly recap these Imaging Concepts without color management and tone mapping the render engines output May exceed the displayable range of standard image formats like jpeg or typical Display Devices this results in color clipping particularly noticeable in highly saturated luminous colors the color management system and tone mapper collaborate to constrain these unbounded variables TR transforming them into a bounded domain this process aims to preserve the essence of the original color information in a visually pleasing manner as far as chromaticities go a color space is used to determine the balance within which colors can be computed color spaces are defined within a theoretical color framework known as the 1931 ciee chromaticity diagram and these color spaces are then defined within that by three red green and blue primary points for instance in the film industry Asus is widely used because it uses several very large color domains which are very useful for cinematic purposes while Asus offers expansive color domains srgb is a more restricted color space commonly used for computer displays and standard image formats the introduction of agx allowed for the use of larger color spaces than what filmik had been using which was was limited to the srgb color space filk was an early tone mapping mechanism in blender and it was constrained to the srgb color space but it handled the conversion of open domain luminosities which helped to prevent the clipping however it didn't handle too well highly saturated colors that were also quite luminous this was known as the six colors problem where highly luminous saturated colors lost individual color nuance and would get compressed into just six General Hues agx was introduced as a way of solving this problem it was also able to work within larger color domains than srgb and so had room to grow for future rendering technologies that required this such as spectral rendering while agx addressed the six colors issue it introduced a tendency to reduce color intensity leading to less vibrant colors additionally some colors could experience a shift in Hue and this leads us into the Kronos PBR neutral tone mapper it was designed to try and solve issues that both filmik and agx presented the user with for instance its primary goal was to take colors that were defined in the srgb color space for instance colors used for product branding and Faithfully represent those so a final render would match as closely as possible to the source colors the new Kronos tone mapper excels in maintaining color saturation and avoiding the subtle Hue shift that agx could produce as well as avoiding the six colors problem associated with filmic and it's specifically tailored for the srgb color space which is prevalent in product visualization design and color specification so the key characteristics of the Kronos tone mapper is better contrast better saturation and improved color accuracy when compared to Source srgb defined color let's take a look at some examples so let's take a look at an example here that's pretty simple I've generated these color swatches that I have linked to these cubes and the Cub's material is in metallic mode I've got these area lights just in front of it to produce these Reflections so this is without any tone mapping you can see that we have a situation where in this bright yellow it's clipping the color is clipping and it looks a little bit funny in the orange one here you can see that without the tone mapping the gradient from the bright area to the darker area is not very good so the functionality of tone mapping is to really improve this but let's go ahead and turn on filmik because filmi is a good reference because it's historically what's been used so filmi does a really good job of smoothing out these areas and making the gradients from the light to the dark areas look really good but we still have sort of the clipping issue where the brightness doesn't really represent brightness it it just doesn't look super bright it's about the color of the yellow and that's it so it's it's not super Dynamic well if we turn on agx agx is super interesting because agx definitely represents the brighter areas better and that's one of the strengths of Ajax is being able to take brighter regions and represent them as it shifts from the base color into a lighter version of it to represent bright hot spots but one of the challenges we get with agx is that it's a little bit desaturated so if we come in now and we look at the Kronos version this is what we get in fact let's do this let's come in and contrast with the original standard kronis does the very best job of maintaining saturation it also does a great job job of maintaining a very good relationship with the original color Hue and tonality but it also does a very good job of highlighting brightness it doesn't just clip let's look at another example here we have a packaging example the first image that we're looking at here is the old filmic when we look at the actual label which is an srgb generated bit map the colors generally match pretty well we look at the green leaves here and we see a pretty good rep representation but I think the scene lacks a little bit of contrast but what I really want to bring your eyes attention to is the background gradient so this is a bit map that was generated in Photoshop and then imported into the background and some emissions applied to it and it's not terribly off but you can see some desaturation when we take a look at the agx version of it well agx again it looks a little flat likee we don't have quite the contrast that we could have but particularly in the background here notice how because this has emissions happening to it and it's brighter agx is naturally sort of desaturating it and it's losing a little bit of the original coloration and tonality so this is where we take a look at the version with the new Kronos tone mapper and look at that Kronos does a really good job of maintaining the color and the saturation of the color from the original bit map but in particular just look at how much more contrast this tends to have just overall as a result of the new Kronos tone mapper let's take a look at another particularly interesting example that I've set up I've got this packaging over here and then I've got these obvious color bars that are pretty saturated this is with standard so there's no tone mapping you can see I've got a bright light sitting down below here casting a lot of Illumination and we really have inconsistency in terms of how each of these colors responds to that hot intense light if we come over and take a look at the old filik version filmi helps to deal with the hot blown out areas there's an area light just off screen here that because of its intensity is producing a lot of the blown out area on the right side filik helps to bring that down but it also tends to wash things out quite a bit filmik handles each of the transitions of these bright saturated colors each in a very sort of individual way and so it doesn't look like there's a consistent light down here so this is one of the reasons why agx was brought in agx creates a lot of consistency in the light gradation for each of the colors but we also lose contrast and saturation now you can always go in and play with the contrast functions but if we come over now and take a look at what Kronos does Kronos maintains the saturation of those original colors but it also gives us pretty even gradation for the light that's down here and it also maintains some nice brightness over here without being blown out again that's one of the things that a tone mapper will do it's got really nice contrast and it maintains saturation of the original labeling quite well let's look at one final example here is a packaging object that's got a metallic type of label on the background this is standard so there's no tone mapping and you can see in this area where there's a reflection of the primary light it's Overexposed it's blown out which again is the job of the tone mapper to deal with this if we take a look at this with filmi well filmi tends to lose contrast it definitely deals with bringing these out of range areas back down but it looks a little bit washed out so if we take a look at the agx version well the agx version again it loses contrast and it's a little bit washed out so this is where the Kronos version really impacts the rendering so this is a particularly good example of what Kronos is good at and in fact if we compare this to the original label art you can see that this area maintains the saturation and the nice gradation and the coloration of the original label so I hope you found this to be a good introduction into what this new Kronos PBR neutral tone mapper is all about

Channel: Christopher 3D

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Id: iQ3m0CfuSmg

Length: 11min 29sec (689 seconds)

Published: Mon Jun 10 2024