Color Matching

[toman311]

Hello,

Color matching is difficult for me in ArchiCAD. If I'm in the OpenGL and I adjust the Surface Color, I can get an exact match to a color chip. Yet when I close out of the Surface Settings, the models color doesn't match what it should be. I found out I also got to adjust the Emission settings as well to control the color. The problem with this is that when I adjust the Emissions color, I can't get an exact match to a color chip. Plus, now there is two places to adjust the color in different ways. This makes getting a visual color match more time consuming than it should be.

I tried turning off the Emission setting in the Open GL Options within ArchiCAD 21's 3D styles, but then everything turns dark. I think that's because all of my surfaces where set up with the Emission option turned on. So, those settings were adjusted and now the Emission color needs to be there.

When I adjust settings in the CineRender settings, I only see one place for color settings. It seems I can get an accurate rendering of a color chip with CineRender. Although, it really just depends on how the lighting is set up.

Getting a color chip match is important in OpenGL because that 3D model is what we show clients during progress meetings. Does anybody have any advice or tips on how to get a color chip match in OpenGL? It would really be helpful to have a color look like how it would in real life.

[Laszlo Nagy]

I think the OpenGL Engine may not be the best choice for this purpose because it does various effects on the surfaces which can then alter their color from the one you defined in the Surfaces Dialog.
I would use the 3D Vectorial Engine with no Shadows, with the settings shown in the attached image. I think that would give you a better chance at color matching.

[Karl Ottenstein]

There is no such thing as an exact color match in a photo realistic rendering without a huge amount of work given the type of match you are asking about. You will be better off adjusting in post-process (e.g. Photoshop) if it is essential. This is not a flaw, it is the way light, materials and color works in the real world which is what any quality rendering software attempts to replicate.

Take a perfect white in the real world. Put it outside and look at it at sunrise, sunset and a cloudy day. Is it white? Never. (Your mind may trick you at times that it is white, but that's another story.) Put it on the ground next to a brick wall, next to a stone wall, next to a green bush. It still isn't white. The combination of lighting and bounced ambient colors is what makes the world look the way it does. The same happens with your color chip. Inside the scene, your color chip will match exactly your wall (e.g.) - but will not match the color chip as you look at it in your office under an bright white light, e.g.

You could attempt to create a perfect studio lighting scenario for your model, with all surfaces not responding to ambient, etc etc ... but the result would not resemble reality at all.

[toman311]

I have gotten an exact color match in CineRender. I tested a box I made from a Morph and colored it with RGB settings for a color chip that I wanted. After it rendered, the colors the light was shining on were lighter then the color chip; yet, the part of the box where no light was shining on had a very accurate color match to the color chip. As has been said above, it depends on the light and the environment. Still in a simple environment, I got a color match. That's all I needed to know since any other attempt in a complex environment with complex lighting, I will know if the color doesn't match the color chip it is because of the complex environment and lighting. So, I'll just know that the render is just making a realistic render.

[Barry Kelly]

Don't rely on what you see on a monitor either.
I have two monitors running off the same video card and they are slightly different in colour.
And I assume printers will all produce a slightly different result as well.

I am certainly no expert but it seems like you can go to a lot of effort to get the colours accurate on one machine but that doesn't mean they will be accurate on another.

Barry.

[Karl Ottenstein]

Barry wrote:
Don't rely on what you see on a monitor either.

Good point, Barry. Professional photographers and graphics designers,, and serious amateurs, have to learn all about a color calibrated workflow which requires color profiling of all devices. One example monitor calibration tool is the Sypder5 from datacolor:
http://www.datacolor.com/photography-design/product-overview/spyder5-family/

You can print special test prints on your printer and send it off to get a custom color profile for the printer as well, which combined with a profile for the specific paper, lets you get the best match possible from your equipment.

But all of that is within the constraints of the color gamut that each device can reproduce - some colors cannot be faithfully reproduced on all devices because of color space limitations of the actual hardware or inks.

Unfortunately, the best organized architect can get their presentation totally color-calibrated, and then show up in a conference room with a non-calibrated projector. 😉

[An aside on the original question of matching a paint chip: some paint manufacturers give the CMYK or RGB values for their chip on the back, or on their web site, which at least lets you get the closest digital coding of the color into your model so that it WOULD appear as correct as possible on any calibrated monitor. This would potentially be more accurate than scanning the chip (your scanner probably isn't calibrated), or trying to match the chip visually (on your non-calibrated monitor).]

[Erwin Edel]

For OpenGL try setting the sun and ambient colours to white. Realistically these would be more yellow and blue respectively, but as pointed out by Laszlo, the base RGB values from surfaces get affected by other settings.

I find that these have the most impact.

Also watch that the settings give a nice even lighting.

Go to 3D Projection Settings (CTRL+SHIFT+F3) > More Sun...

Personally I have set both sunlight and ambient light to pure white colour. Sunlight at 80%, contribution to ambient at 30% and ambient light at 25%.

The colour tinting from the sun settings is visible in the 3D thumbs in surface settings for internal engine.

The Emission, Reflection and Glowing secions of settings are also affecting the colours, especially noticeable in horizontal vs. vertical surfaces with the same surface material applied.

There used to be noticable difference between how BIMx handled textures and plain colours, even with all other settings the same. I used to have 1x1 pixels single colour textures to work around this.