Join Brian Bradley for an in-depth discussion in this video Blurring reflections, part of V-Ray 2.0 for Maya Essential Training.
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To create our blurry chrome material, one of the things we are going to need to do is quickly run through re-creating our basic pay chrome setup. Of course, the first thing we need in our scene is an object to apply our material to. So if you just come to the Layer Editor, just make certain you click on the Layer Editor tab at the side of the Maya UI. We are just going to come and make certain that our Clock_Timer layer is visible. What we are going to do is applying blurry reflections to this portion of our object. One I thing I want to be able to do is compare our blurry reflections with the mirror like chrome that we applied to our butterfly object.
At this moment in time, we have to checker map controlling the level of reflectivity there though if you recall. So let's come up to our Window menu, come to Rendering Editors, let's pull up the Hypershade for ourselves. I just want to clear that checker map out. So if we select the material, make certain we are in the Attribute Editor. You can see we have got the correct material, it's got the 2 appended. So if I just right-click and then select the Graph Network option. I am just going to select our checker node and our place2dtexture node and I am going to delete those. You will notice though that in the preview of our clear chrome material, things have gone a little bit muted, and in fact, if we come in our Parameters here, you can see if we come to the Reflection controls.
Now that we have deleted that map our reflection color has really just itself to a halfway point. We are getting a mid gray value. We of course need that to be white, so that we can compare to those mirror like reflections. So that's good, we've got outside of being there, and I am just going to come to Graph>Clear Graph, because now we want to create a new V-Ray material for ourselves, and we are just going to call this Blurry_Chrome_2. We do, of course, need to apply it to our object, so let's select this portion of our object in the scene, right- click inside of our work area, and Assign Material to Selection.
Now if we take a render, we will see that we have that material properly assigned and ready to work with. And as you can see, that is exactly what we have; we have our gray material assigned to the relevant objects and we have got a nice clean reflections that we can make a comparison with. So let's pull back our Hypershade window. We do, of course, want to select our material so we can work with its parameters inside of the Attribute Editor. Now the first thing we need to do is make certain that our material is completely reflective, so let's take our Reflection Color and we can slide all the way up to white.
Now adding the blurriness, the noisiness to our reflections is a very simple matter of working with these Reflection Glossiness parameter. So if we set a value of .7 in there and let's use Maya's Region Render functionality, so let's just left mouse click and drag a region around our object and select the Region Render option. You can see we do indeed get blurry reflections on our object. Now something we have to keep in mind with regard to these kind of noisy material effects is really the fact that our DMC sampler will affect how this noise is looking.
In fact, if we just come up to the Main toolbar and we click on Render Settings window icon, let's come in to the Settings tab and let's just demonstrate how things would change if we make a change to our current DMC control parameters. So let's set a value of .1 in there, and again, let's take a Region Render. Instantly you can see that our reflections are much, much noisier, in fact, probably these are unacceptable levels of noise. Just so you aware though that the DMC sampler controls will affect how our blurry reflections are looking.
It's not just down to the Material Settings that we are working with. So let's just set those Threshold values back to 0.01 just so we are getting these renders back, and let's go and just re-render that particular region just so we are back to the default settings. And if we just come back to our Materials controls inside all of the Reflection controls section, we can see there is an option in here entitled Use interpolation. Now this is an option we can use if we really want to smooth out our blurry reflections.
So let's just check that. Now this option is not working in isolation, it isn't just this checkbox that will control the quality of our blurry reflections. Now if we just scroll down in our V-Ray Materials controls, you see we come to this Reflect Interpolation section, in fact there is a Refract Interpolation section as well, because the Refraction options, you can use interpolation in the Refraction options as well. Here we get to set Min and Max rate and we can control the number of samples that are blended or averaged together, just so that you wee aware that those controls are down there.
So now with Use interpolation enabled, let's take a look at how our reflections will be looking. And you can see that that does indeed smooth our reflections quite drastically. They are still blurry obviously, but they are looking very, very smooth, indeed in fact oftentimes, this look reminds me of the kind of fake brushed metal looked that you get when these type of object use plastic instead of metal in their construction. One thing to be aware of when using the Use interpolation option is the fact that this isn't really going to play very nicely inside an animated sequence.
Because we are blending or averaging samples inside of the material, oftentimes you will find that from frame to frame the interpolation will jitter, it will jump around. And so as we say not really a good option to use if we have any kind of animation in the scene. I just want to uncheck this Use interpolation option, because we want to now look at another control inside of our Reflections set here. And we come down to this option Dim distance On, essentially what we have with this parameter is the ability cut off our reflection rays for this particular materials.
We can tell them to trace so far out into the scene and then stop. In fact, let's give you a demonstration. If we set this down to a value of 5 which means we are now setting our Reflection rays to a for maximum distance or to travel to a maximum distance of 5 cm in the scene. If we take a Region Render, you can see that where our reflections rays have traveled a distance of 5 cm and encountered a geometric object there returning a reflection or piece of reflection information. However where there are no objects within that 5 cm distance we are just getting a black return.
So you can see we can definitely limit how our reflection rays are working. If we don't like this harsh cut off, we have this Dim fall off parameter that will give us a gradient to the fall off between the reflections and non reflection areas of our material. So again, let's just uncheck that and take a re-render. Now currently, the light interaction of the surrounding environment, the reflection rays that we are working with, and as we say the lighting in the scene, all of that is being handled, and if we just scroll to the top of our Reflection rollout, you can see we have this Brdf type, that is, Bidirectional Reflection Distribution Function.
This really is the control that handles how light and reflective properties will interact with one another. Now let's just saved that we currently have and let's come and make the change. Let's switch from the default Blinn over to Phong, and again, if we Region Render and then compare the results, you can see that there is a significant difference in the way our reflections are turning out. And again, if we switch from Phong over to Ward, let's save what we have at this point and take another Region Render.
You can see that if we compare all three of these renders, the look of our reflections changes between each and every one of them. So again, all the controls are at work for determining how our blurry reflections will work, in fact, this control will affect all reflections in the scene, but it just really shows up very, very clearly when we're working with blurry or noisy reflections. So let's just set that back to Blinn again. So blurry reflections, once we understand how the controls and the parameters are working, very easy using the V-Ray material.
What about increasing the difficulty level for the V-Ray material now, by asking it to reproduce a material type that is both reflective and refractive and is so common to people that's used by them every day that they really know just how it is supposed to look. Well making glass is what we will tackle next.
- Installing and setting up V-Ray
- Using the DMC Sampler
- Understanding color mapping modes
- Adding a spherical fill light
- Working with the V-Ray Dome Light
- Using irradiance mapping and the Light cache
- Creating diffuse color
- Making reflective materials
- Creating translucency
- Ensuring quality with image sampling
- Controlling the V-Ray physical camera
- Creating a motion blur effect
- Compositing V-Ray elements