Join Brian Bradley for an in-depth discussion in this video Putting extra elements to work, part of V-Ray 2.0 for Maya Essential Training.
As we're still working with our render elements Composite, you can continue from where we left off in the previous video or you can load the Chapter09 Elements_02 Composite file from your Composite files folder. Now to this point, we have managed to reconstruct our separate render elements. We have re-created the render as it would've come out of the V-Ray render engine. What we want to do now of course is dip into the power of a compositing approach to 3D rendering, by making some adjustments, some improvements hopefully, to our final image.
Now the first thing we want to do is add-in our ambient occlusion element. We are going to create some extra contact shadows in our image for ourselves. To do this, we need to come into our work area. I'm just going to middle-mouse click to bring up our Gate-UI, we will swipe across and we want to come to our Composition tools and we are going to grab another Blend & Comp tool and drop this in the work area. Now we want to take our existing chain and plug this into our Back input. We can take our ambient occlusion or V- Ray Dirt render element and we can pipe that one into the Front input.
Now when we select the Blend & Comp tool, we need to change the Blending mode but this time, we're not going to use the Additive mode as we had previously, we instead going to select and again we are just going to need to do some tweaking with our Composite UI to get the Blend modes to pop-up correctly. In here we are going to choose the Multiply Blending mode. We are going to use this because essentially it will take all of the light values and ignore them from this rendered element, and just instead overlay the dark values on top of our existing composition.
Now of course I said this so many times the effect may be a little bit too strong if we just compare to our controlled image you can see that adds quite a lot of extra darkness under each of our vehicles. We can with the Blend & Comp tool selected, just again gain access to all of the controls in the UI. As our Ambient Occlusion effect is plugged into the Front port, we can take this Front Gain set of controls and we can just dropdown the Opacity just to make that effect a little bit more subtle in the scene.
So it's something around about 0.25-0.26 will work nicely. Again if we just compare, you can see that it adds a little bit of extra contact shadow but without being overpowering. Well next we are going to use our Multi Matte element. So I am just going to drag this to the front of our Composition because we are going to add this in a little bit earlier in the Composition chain. We do need another tool to pipe this into, so middle-mouse select the Gate-UI and swipe. This time we are going to go into the Color Correction tools and I want to grab for myself a Color Correct Basics node.
Now we could just drop this in the work area, but one thing we can do in Composite if we just hover over our connection line, you can see we get this blue highlight, which means, when I release the mouse button, it's just going to drop in there and be already connecting for us. So that's nice and quick piece of functionality we can use. Now we need to take our Multi Matte Element. I'm going to plug this into the Masking Port. Of course at this point in time, our Color Correct Basics node doesn't know which of the channels we have in this particular element. We have red, green and blue.
It doesn't know which channel we are using for the masking operation. So let's come to our Masking tab, come to the Channel option here as we want to correct our red car, we are just going to set the Red Channel as this is the one that we used for that particular vehicle. Now we can come back to the Color Correct Basics tab, and you can see, if we just drag around in the viewport we can indeed Color Correct what we have. We can work with the Hue, we can work with the Saturation in the scene if we want to, and off the Color Correction tools are available tools, we can use with this Multi Matte Element.
We do however have to be careful when we are color correcting in this fashion. If I just come and select the end of our Composition chain, you can say, yes, we do have a color corrected car, but you can see in our reflective objects we still have our red reflections. We would of course really need to create Matte elements for the reflection objects and then color correct those as well. Then using our final element, the Z- depth element, we are going to create a little bit of a shadow depth of field effect for ourselves, so we need another tool in our work area, so middle-mouse click, swipe.
This time we are going to come to our Filtering effects and we're going to use the Lens Blur Tool. So if we drop this in here, we can take our existing chain and pipe this into the image input port. I'm just going to grab our element here, drag this down, and we are going to connect this not to the Masking port, we want to place this in the Modulation Image input. Now if I just left-mouse click and drag, you can see we get a depth of field effect in our image. Of course we are not performing this operation in a completely technically correct manner.
We really would need to mask each of these vehicles separately, pull them off the background, and then add our depth of field effect on top of that final composition. But you can see how the tool works; you can see that we can get a very nice effect just using this Z-depth element. Of course finally, all we need to do is add our gamma correction back into the final chain, so let's select our existing Color Correct Basics node. I am just going to use the Ctrl+C, keep the shortcut. I am just going to hover my mouse over the end of our Composition chain, and then use Ctrl+V and we add that in there.
Now what we need to do is connect these two together, and you can see, we have our gamma corrected render. So using render elements, we have first of all successfully recreated our V-Ray render correctly. Inside of Composite we've put all of the elements back together just as they came out of V-Ray. We have also touched on the power of the render elements and compositing workflow to produce some postproduction changes. We have done this without any re- rendering in our 3D application at all. And remember, this is barely the tip of the iceberg as to what can be done, with V-Rays powerful render element toolset.
In fact, in the next video, we will run you through using a brand-new render element added to V-Ray 2.0 that opens up a number of relighting options for us using postproduction tools.
- 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