Could you please add some variation? We are loosing detail in that area.” Let’s send this and hope the client likes it! Even if you go nuclear with the intensity of the light (as we did here), values will be clipped to the wavelength set by GaussianSpectrum. Power of 200 watts? You bet! Still red? Yes sir! The color is holding up much better now. Power of 4 watts? Check! Red color? Check! Moving on. Similar settings, just swapping RGBSpectrum for GaussianSpectrum.
This analogy is, most certainly, scientifically incorrect but helps to get the point across.Īlright, lock and load! Let’s try this one more time. Mentally translating this to HSL, you can think of “Wavelength” as the “Hue” while “Width” and “Power” correlate to “Saturation” and “Lightness” respectively. It is worth mentioning that Octane remaps the length of the electromagnetic radiation (ranging from 380 to 720 nanometres for visible light) to a 0 to 1 gradient, labeled “Wavelength”. Hopefully, it is clear enough that the GaussianSpectrum interface above is used to describe a wavelength value from the spectrum chart bellow. What’s the alternative for generating colors in Octane Render? GaussianSpectrum! That’s why it is nearly impossible to get the “red, glowing, neon tube”, the client is after, and still keep the light source as bright as it is. First, the color was clipped to magenta, then, after injecting values in the rest of the RGB channels – to white. Pushing a 100% red emitter to a power of 200, makes these precision artefacts visible. This is clearly visible in the images above. Note, however, translating RGB to wavelengths (and vice versa) will never return perfectly matching values. That’s why, internally, the engine converts RGB colors to their closest wavelength equivalents. Well, it’s now obvious that the output of RGBSpectrum cannot be used directly for sampling. So, “What does this have to do with anything?” you may be asking.
The resulting images are closer to real life, more precise and easier to clean up. This means, simulating light sources and object surfaces is done based on real-world wavelengths, as opposed to the more widely used RGB method.
The way Octane renders the scene is via a method, called “Spectral Rendering”. To explain the behavior of RGBSpectrum, we need to understand (or at least have some idea) how the engine treats light. God, why do bad things happen to good people? That’s it, I am installing Arnold!” where did my red go?! Why is this white? I am so confused. Wisely, you introduce some variation to break the perfect red. Looking back at your RGBSpectrum – it’s 100% red with no information in the Green and Blue channels. Render engines do NOT really like “extreme” values like 100% black, 100% white, 100% saturated, 100% glossy etc, you get the point. What the hell is that?! Magenta? Noise? Fireflies? I am doomed!” And just before you start crying (usually online) how broken Octane is, swearing “I’ve never had these problems with V-Ray” and so on, you remember something important. “Bah, that’s easy!” you say and pump the power up to 200! Nevermind, back to work.Ĭlient feedback comes in and it goes like: “ That’s cool and all but. Confidence starts building up again and you are secretly thinking that, with that skill set, you should be working at ILM. You assign an RGBSpectrum and reduce the watt power down to 1. Standard workflow – an Octane Material (with no Diffuse color) and Texture Emission. Doesn’t take long before the first test render is complete:
And so, you go with the freaking neon tube. Better? Better! You know, every little project gets you one step closer to that awesome job you’ve been waiting for all your life. “For the love of mother and child!” As usual, you go scream into a pillow for 5 minutes. “Hello, can you make me a red, glowing, neon tube?” Let’s see – social media notifications, a newsletter you never signed up for, new drugs that will make your sex life better, a new render by beeple and oh, wait, a job offer! Subconscious images of self-knitting Nike shoes, shiny car renders, explosions, transformers, or whatever else you define as “cool”, all projected in front of your eyes as you anxiously open that message. You don’t, but it feels like it! A few unread e-mails in your inbox. It makes you feel like you got your shit together. You are starting to feel the little rush after that first sip of good, strong coffee. Which one do you prefer? Not sure? Don’t care? See why!