Join Brian Bradley for an in-depth discussion in this video Depth of field: perspective viewport, part of V-Ray 2.0 for Maya Essential Training.
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Let's take a look now at how we would create an in-camera depth of field effect when rendering from a Standard Maya Camera. Now this could be a camera we have added to the scene or one of Maya's Standard Perspective viewport cameras. Firstly, we need to be certain that we are viewing through our Depth of Field camera, which we are but let's just go and make certain of that by checking that option. And of course we do want to select our current rendering camera, it is a V-Ray Physical camera at this moment in time, but we're going to want to change that and essentially we will turn it to its original state which was just that of Standard Maya camera.
Now there are couple of ways we could do this inside of our Extra V-Ray Attribute rollout, we could just uncheck the Treat as V-Ray Physical camera option if we were going to come back to it. If we want to get rid of it altogether, we just come up to our Attributes dropdown, come to the V-Ray section, and uncheck V-Ray Physical camera. Now we are rendering, once again, with just a Standard Maya camera. Of course, that present a little bit of a problem and that we have now killed our Exposure Control Mechanism. We were compensating for the lighting levels in the scene by using the V-Ray Physical cameras Exposure Settings.
In fact, if we were to take a render at this moment in time, let's just pull Maya's Render View for ourselves. We are here working with some pre-rendered images. Depth of Filed is a render intensive effect of course, so we are just going to step you through the renders that result from the changes we will make in our parameters and options. Now as you can see, with our Exposure Control Mechanism removed from the scene, we have a very overbright render indeed. We really need to make some changes to make our lighting levels a little more acceptable. So let's come to our Window menu, let's come down and open up the Outliner for ourselves, of course, make certain that you are filtering by Lights and Light Sets and you should see all of the light elements in the scene.
First of all, select our V-Ray Dome light, we are just going to drop the Intensity multiplier down to a value of 0.1. Now we can go and grab a V-Ray OverHead Direct light, and we are just going to set its multiplier down to a value of 25. We can close the Outliner now, and if I show you the render we would get, you can see we have a much more acceptable level off illumination in the scene. What we need to do now, of course, is enable our Depth of Field effect. So we want to pull up our Render Setting window. So let's choose the icon on the toolbar to do that for ourselves.
Into the V-Ray tab, let's close up the Image Sampler rollout and come instead to our Camera rollout. In here, you can see we have a number of Camera Effect options, one of which is Depth of field. So if we just put a check in the On box, that system now becomes active and the parameters are available for editing. Three particular parameters are of greatest interest tools. First of all, the Aperture setting, this is the equivalent of the F-stop in a real camera or the F-Number value in the V-Ray Physical camera.
We do need to be aware that the values will work differently. If the lower the values in this Aperture setting, we will get a smaller aperture; if increase them, we will get a larger aperture. That of course it is the opposite way around to our F-stop values. The Focus Distance, of course, will determine the focal point in the scene. It is working in scene units, so we are working at a centimeter value here so whatever distance from the rendering camera our perspective viewport this value is set, that is the focal point of the scene. And of course we have our Subdivs value that will work to control the quality of our final Depth of field effect, of course, working along with the Image Sampling and DMC Sampler controls.
So let's work with some settings and see what kind of effect we can get using this system. So I will just set an Aperture Setting of 1 centimeter, we will set Focus Distance 40 centimeters, and we are just going to set a Subdivisions parameter of 12 in there, just so that we can get a little bit of quality out of the system. With those settings in there, we would get this Depth of field effect for ourselves. So as you can see, we have a very nice Depth of field effect, very narrow. As we go up towards this yellow ball, it is out of focus, our first row of pool balls are coming back towards the camera out of focus, but we can see that the effect is working cleanly and nicely in the scene for us.
What though if we wanted to change the focal point in the scene? Well again, we just need to work with our Focus Distance parameter. So this time, if I set a value of 115 centimeters in here, we would go from this to this render, which as you can see, it changes the point of focus towards the top of the table. You may notice though that we have deepened our Depth of field effect as we have shifted the focus. If we want to recreate a shallow of Depth of field effect off to that top end of the table, we may have to adjust our Aperture settings as well.
Okay, what about finally increasing the Blur Effect inside of our Depth of field effect? Well to do that, we just want to work with these Aperture control, in fact, what we will do is we would double the value in here from 1 to 2 centimeters and we would go from this to this, but as you can clearly see, it is a greatly increased blur effect. You may also notice that there is a lot more grain apparent in the effect now. Well, that is because we have to increased the amount of blurring taking place but we haven't increased the quality of sampling.
So you may need to increase your Subdivision levels or you may have to work with V-Ray's Image Sampling and DMC Sampler controls to clean this up a little bit as we have increased the Aperture setting. So between this particular system and V -Ray Physical camera, we've seen that there are two very easy to control methods for creating an in-render depth of field effect using V-Ray. Naturally, there is a third option available tools, this is by means of render elements, but we will look cover that Chapter 9. Now though let's move on to recreating another photographic effect that of Motion Blur.
- 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