Artrage Oil Blending Problem - Colors are Changing

[MattRage]

I'm using Wacom Cintiq Companion (1st version) and Windows 8.1. I love, love, love Artrage for oil painting, but when it comes to blending, it becomes very frustrating. Some colors when blended together, produce undesired results. For example I'll try to blend blue and grayish blue, and Artrage starts to create cayan, spreading it to other parts of the image where I'm blending. I understand that if I blend yellow and blue together I get green in real life. That's understood. However I'd love to have a blender that does not create new colors when blending two together, while still maintaining that brush-stroke look. I have tried selecting and deselecting "real color blending", but that didn't make a difference. If I blend light brown and dark brown together, the colors start to turn very reddish, nothing like I intended.

The problem of stray colours getting introduced to blending is something we're continuing to look in to. Basically, small rounding errors in colour calculations which occur because of the limited range of available values can become more visible when colour blending operations are repeated hundreds upon hundreds of times - small errors compound and become bigger ones. Because Artrage handles its physical media in an unusual manner (which is what gives us the brush texturing and other natural effects) we're more susceptible to this than many other packages.

We've been working on various approaches to solving this for some time and have introduced various tweaks in different versions to improve it. We're definitely going to will continue working on it because it's something we want to hammer out of the blending algorithm, but in the meantime you might find that Real Blending turned off reduces the instances of Cyan specifically (there's a point of the real blending curve that is tending towards Cyan and we're looking in to that).

If you've got a specific set of colours that's causing issues feel free to drop a PTG file with a sample of them to [email protected] and we can use that to help as we go through adjustments to the system. Sorry I couldn't give an immediate solution, it's a hugely complicated system and the process of ironing out issues tends to work like a seesaw, swinging one way then the other, until hopefully we can balance it out fully!

[Delofasht]

The problem of stray colours getting introduced to blending is something we're continuing to look in to. Basically, small rounding errors in colour calculations which occur because of the limited range of available values can become more visible when colour blending operations are repeated hundreds upon hundreds of times - small errors compound and become bigger ones. Because Artrage handles its physical media in an unusual manner (which is what gives us the brush texturing and other natural effects) we're more susceptible to this than many other packages.

It is good to know that the color mixing engine is being worked on. As an interesting note, I started really digging in with this study of color blending some time back. I believe the issues we see are due to the color space in digital being an equal balance of red, blue, and green for mixing. The spectral analyses I'd been learning to interpret show a different arrangement of color space, how that lines up with pigments in traditional media is interesting to say the least. While a huge gamut of colors can be made using RGB models, color mixing in a natural manner is extremely difficult because it doesn't represent what we see in actual life. Short of writing a new color space. . . I'm not certain there is a way to effectively program color mixes.

Currently in "Real" color blend mode, blues mixing into reds will often push magenta to 100 saturation with any mix starting >50 saturation to start. Reds leaning orange mixing into cyan should nearly perfectly neutralize, but instead push to green on the edge of the red side mix consistently, with saturation scattering hard. Green plus a blue (cyan leaning toward magenta) should result in a darker green but instead goes into Cyan.

In natural media there are 3 colors we cannot mix to: cyan, magenta, and yellow, this should be reflected digitally as well. This is not to say that a CYMK color space is better by any means, just that we can't get to higher saturations of those colors by mixing less saturated versions of colors next to them, blue + green shouldn't get me even near a higher saturation cyan, likewise an red orange + cyan shouldn't end anywhere near a green regardless of saturation starting points, and red orange + blue (cyan leaning toward magenta) shouldn't actually go to magenta, when mixed with natural media paints I end up with a very muddy brown color. Pigments have various degrees of transparency as well that further adjusts how they interact, opaque pigments will mix more neutrally in a slightly more lateral fashion (where value doesn't shift as much) where transparent pigments tend to work almost multiplicatively, darkening expontentially. This is an aspect of color mixing we do not see at all in digital, where color mixes are generally somewhere between the two. This is a side of painting and paint control I'd love to see, basically being able to adjust these color mixing curves ourselves, even if it's through a secondary tool. Someone out there somewhere given the right interface would make these as near perfect as possible (could be me), currently in order to adjust these settings I would likely have to learn a lot of programming language, and while I do find it interesting, I'm not particularly interested in expanding my studies to include that while I'm still working on perfecting my artistry.

Levers for paint controls would benefit from controls on transparency versus opacity, "pigment" particle size (allowing creating granular paint for both oils and watercolor, that reacts to further paints added to the surface), and controls for the "binder" more or less of various modifiers to affect rate of application of the paint (rheological handling simulation, stiff paint vs fluid). These in turn would be adjusted by color curve blending based on an external addon or something that could allow us to fine tune the color space to represent the colors we would expect when mixing in natural media (expectations of some artists can vary, some expect to mix red-orange plus blue and get a purple. . . but that's not how color space works as I understand it in practice with natural media). By hopefully keeping the settings separated from the basic tools, the UI can remain relatively simple but allow the user to greatly impact how the tools react to better simulate a personal expectation. Similar tools for brush settings could be wonderful as well. . . (shape, number of bristles, length of the bristles. . . for stabilizing brush strokes, and so on).

Sorry to have gotten off topic there, a bit hopeful and excited by the possibilities that a color gamut curve adjustment tool might yield. . . especially one that allowed for simulation of transparent or opaque paints (since they react differently on the color curve in terms of variation in saturation, value, and hue even).

[Piotr_BTF]

Hi all
I'm facing the same problem as described at the beginning of this thread. The last comment was in 2015 therefore I would like to know is ArtRage team made any improvements on blending colors. While mixing two shades of green I got reddish tint after blending it. Sometimes the unexpected color is green. It all happens when blending in one place for more than just a few brush strokes. Also is there a way to have a clean brush without any paint on it - that mixes only what is on the layer, nothing more?

[Krigen813]

Hi all
I'm facing the same problem as described at the beginning of this thread. The last comment was in 2015 therefore I would like to know is ArtRage team made any improvements on blending colors. While mixing two shades of green I got reddish tint after blending it. Sometimes the unexpected color is green. It all happens when blending in one place for more than just a few brush strokes. Also is there a way to have a clean brush without any paint on it - that mixes only what is on the layer, nothing more?

I would suggest that you start a new thread in the support (insert OS here) section and included as much detail as possible such as your version of ArtRage and operating system. Also anything you have tried to get rid of the problem and possibly an image that shows what is happening to you and if/how it can be reliably repeated.

[Piotr_BTF]

Ok, I will

[DarkOwnt]

Ok, I will

Hello P:


Once you have created a custom brush you like, you can make a "blender only" variant of it by reducing Color Refresh to 0. This should reproduce the grain, texture, and depth of your preferred brush but lays no new colors down.



This custom brush might be a good start for you to play with:


AR6DOsCustomBrush.arpack



It's a bit on the grainy side. It was used to produce the following strokes:






And this painting:

[nekomata]

Hi all
I'm facing the same problem as described at the beginning of this thread. The last comment was in 2015 therefore I would like to know is ArtRage team made any improvements on blending colors. While mixing two shades of green I got reddish tint after blending it. Sometimes the unexpected color is green. It all happens when blending in one place for more than just a few brush strokes.

they did, but all of those appear to be limited to the custom brush tool introduced in ArtRage 5 and upgraded to support paint depth and wet-on-wet blending with oil paint tool brush marks in AR6.

core blending model for oil brush, paint roller and palette knife tools seems to remain unchanged, still sometimes producing the undesirable color granulation.

Also is there a way to have a clean brush without any paint on it - that mixes only what is on the layer, nothing more?

Palette knife tool and the custom brush blender presets would be your best option, but you can drop any brush loading to zero. I don't use them often, but I recall keeping thinners value under 50 % would be best for this too.