In this collection of Softimage tutorials, we will discuss the various nodes found in the Illumination section of the Render Tree. We will be discussing topics such as creating realistic car paint, exploring subsurface scattering materials to simulate translucent surfaces, overriding shadow color and transparency on individual objects, shading hair strands created in Softimage, rendering soft-shadowing effects using ambient occlusion, as well as many other tips, tricks, and techniques for using the Softimage Illumination nodes. Software required: Softimage 2012 and up.
Kyle was one of the first authors for Digital-Tutors (now a Pluralsight company) and has been a part of the team for over 10 years. Kyle began his career in computer graphics education as a college instructor and worked as a Digital-Tutors rendering tutor and curriculum manager since 2002.
Introduction and Project Overview [Autogenerated] in this lesson will be exploring some of the transparency and the reflection properties that are found on most all soft image materials. So nearly all of the material types in soft images that are found underneath this sort of a top grouping here, almost all of these shares some of the same properties as faras reflection and transparency. So let's come in and take a look at these will come in to my scene here. Don't take this little tourist, not a piece of geometry. And just very quickly, I'll just, uh, all right, click and go to inspect material. Now, if we could take a look inside the transparency and reflection again, we do have ah few properties in here and again. These are pretty much universal toe all of these different materials that we have kind of in this top cluster appear. So take a look at these. Let's go ahead and all personal the cuchi on my keyboard to draw to render region all right, And let's start with the transparency. So the transparency is pretty self explanatory as we start to increase this transparency and start to add some kind of a coloring here, you can see that we're starting to get a little bit of coloration in our transparency. Now you will start to notice that as I begin in increasing my transparency, you're starting to incorporate some kind of a color into this. You notice it might seem that we are actually starting to get a little bit more of a pink coloration in this piece of geometry. Now, the reason for this is that we're actually having an additive color effect between this transparency and our diffuse color. So, typically, if you start to introduce some kind of color into your transparency, well you want to do is go into your illumination tab and take a diffuse color all the way down to pretty much black. And now you can see that we're getting this color of our transparency with no additional effect from this diffuse color. So let's come back. And if we want to, we could actually move all these sliders together. If we just press hold the control key on our keyboard while we start to slide these we want to start to actually create some kind of a gray scale or ah, single color value. Now, Balu, this we can choose whether or not we want to use the Alfa. So if we have some kind of an image or a texture plugged in here that uses an Alfa Channel weekend tele to draw from the Alfa Channel that image we could also sort of start to use this almost like an additional slider now. So as we start to come in and adjust this, you'll notice that it pretty much start swinging or any colors that we may have said in here. Now, if we want, we could also invert this effect. So again, if we had some kind of a texter plugged in here that uses an Alfa Channel, we could choose to invert or not invert that Alfa Channel that's coming in. We also have the scale, which is essentially just a simple multiplier this So as we start to bring this scale down, this will be a little bit more apparent If I were to disable my use Alfa, you can start to see where this scale again. Just X is a very, very simple color multiplier just intensifying the effect of whatever we have set up within our color. Now, below this, we have the frost, which starts to give us a little bit more of a kind of frosted glass appearance. So you notice as we start to increase this really nothing is happening. And you won't see any kind of effect from this frost until we also start to introduce more samples into this. So as we start to introduce samples again, really not a whole lot of an effect that we are seeing here. That's because once again, neither one of these sliders were really have much of an effect until we start to introduce refraction. Now, refraction is a light rays tendency to actually change direction as it passes through a surface. Now, most transparent surfaces are refractive, at least three slightly. So with something like water, you're probably going to start to get into something a little bit closer to 1.34 refraction. He's gonna be a little bit easier to see if I were to temporarily just bring my frost and samples down. A refractive index of one pretty much means that there is no refraction. That is basically the refractive index of air again. Something like water. You're gonna have about 1.3 something like glass. You're gonna have about 1.5. And now you can start to see where we're actually getting something that looks quite a bit more realistic. Now again, back to our frost and samples as we now start to introduce the frost and samples. Once we have some kind of a refractive index in here, we should start to see a little bit more of a stronger effect. So with this frost, as we start to now, dial this up. You can start to see that our tourists is starting to kind of blow around again a little bit more of a frosted glass type appearance. Now, you will notice that there is a lot of noise and a lot of artifact in here. This is what this samples is designed to fix. So as we start to increase our number of samples, you should start to see that this noise gonna starts to smooth and kind of clean itself up. You'll also notice that you render start to take quite a bit longer at this point, so you'll definitely want to be careful with these different values. So that's how we can start to bring a little bit more realistic glass type appearance into this. Now you may have noticed if I were to bring my samples and my frost back down to set my refractive index back to one. You may have noticed that we do have a little bit of artifact ing and some anomalies kind of right in here where the all these other parts of our tours are transparent. Except for these little guys right here. Well, this is completely normal. And what's happening is that soft image actually sets a limit for how many's surfaces it will calculate in order to arrive at any kind of transparency. Now, in this case, you'll notice that we actually do have a lot of surfaces that are overlapping right in this area, and what happens is they're actually too many surfaces. So before soft image consent to raise all the way through to the other side, it's going ahead and starting its final calculation. Now we can fix this if we go into regions and go to all options. Let's go ahead and go into the optimization tab and look for refraction in our case, which is the transparency calculation so we can do we start to bump this up, do a little bit higher value until we introduce enough calculations in here to make sure that soft march is able to reach all the way through to the back side. Now it's very briefly talk about reflections. So go ahead and go back in my property page and I'll go ahead and temporarily disabled my transparency. Just turn off my little check box here and now we can start to introduce some reflections. So pretty much the same attributes and same parameters that we saw appear in the transparency where we can now start to introduce some reflection in here. We can also start to colorize our reflection if we need to just below here. We also have the ability to control the scale again, just a same thing that we looked at previously. We can also start to introduce more gloss into this. So just like before, as we start to introduce the glossy Lotus that really nothing happens until we start to introduce more samples. So as we start to dial the samples up now, we should start to see a little bit more of an effect from this gloss where we are starting to get something that is maybe not quite so shiny and chrome like, but maybe a little bit softer, maybe a little bit rougher type surface. And again, by starting to increase the samples a little bit higher, we should be able to fix up a lot more of that Louise in that artifact ing. But again, keep in mind that these will start to significantly slow down our render. So start with a low value and then gradually work your way up until you eliminate as much of the noise as you feel like you need to. So, again, these different settings that we've had a chance to look at are going to be pretty much universal across all of these different material type. So once you figure out how these different settings work on one material, we can start to introduce these refraction and reflectivity capabilities on pretty much any material type