Join Brian Bradley for an in-depth discussion in this video Using Render Mask, part of V-Ray 3.0 for 3ds Max Essential Training.
- One big challenge that simply comes with the territory when trying to complete high quality, high resolution renders on a project would be the sheer amount of time that has to be allotted to the rendering of the final images. This challenge can quickly turn into a serious problem however, if we are told very late in the day that alterations simply have to be made. Situations like this are part of the reason why many studios have long since turned to a compositing-based pipeline. Providing as it does, the freedom and flexibility to make changes, sometimes very significant ones, long after the actual rendering is done.
Let's suppose though that we have just finished quite a lengthy render on a project and that we have produced it without the need for any further compositing work in mind. In other words, what we get out of V-Ray is everything that we have. No render elements, no masks, no mats, nothing but the final image. At this point though, our art director or client comes to us and says that certain elements in the image have to be changed in order for the project to receive final approval, and so payment. Well, this is where V-Ray's render mask tool may be able to help out, giving us a render that could take minutes rather than hours, or hours rather than days.
To demonstrate how this works, we have our, by now familiar, kitchen shelf scene which has been rendered here at full HD resolution. So 1920 by 1080. Now because of the quality settings that we have been using here, this render, as you can see in the history buffer stats, took only about 19 minutes to produce. But a really complex frame of this size could very easily take hours to render. What then if our art director or client came along and said that the white ceramics in the scene really needed to be a pale orange color? Well let's alter the material according to those instructions by opening up the Material Editor and coming to the Ceramics tab.
Here, we can double-click the white ceramic material and in the diffuse controls, pick the orange color that we want to use. Now assuming that a complete re-render is totally out of the question, let's right-click on the material header, and from the "Select" flyout, choose the "Select by Material" option. Now unfortunately, in the "Select Objects" dialogue that pops up, you can see as I scroll down here, that for some reason, either 3ds Max or V-Ray thinks that the wall geometry should be included in this selection.
As this is definitely not the case, let's just hold down the control key, and then left-click to remove that entry from the list. Once done, we can click select and see that all of the relevant geometry has become selected in the scene. All, that is, except this group of plates on the middle shelf. So seeing as we definitely do want that, let's hold down the control key again, and add that to the selection. Now comes the really clever V-Ray bit. In the "Render Setup" dialogue, in the "Image sampler" roll out, we have this "Render mask" drop down that houses various ways in which we can create a filtered selection to be rendered.
We can use a texture or black and white mask to make that determination. We can use standard max include/exclude functionality, we can filter by layers, or we can, as we will do here, render only the selected objects. With that option enabled, let's grab the V-Ray frame buffer and hit the render button. What we see now are some pretty quick behind-the-scenes GI calculations and then, V-Ray goes ahead and renders just the objects that have been selected in the view port, complete with in-scene reflections.
Which at first seems to be just what we need. Until, that is, our render buckets get to the ceramic serving platter. The white refraction that has been captured in the glasses sitting in the front of it, starts to look really odd indeed now. Which does highlight a potential drawback of the render mask tool in as much as reflections and refractions will need to be scrutinized very carefully if we're going to go ahead and make use of it. Seeing as everything else here does look fine however, let's go ahead and take a second render mask pass by selecting just the glasses that are creating the problem.
And then with our render mask still active, and still using the render selected objects option, let's take another render. What we end up with, is an image that we could easily pass off as being the initial, original first-time render. And of course, even though we acquired this in two, rather than one, render mask passes, it still only took one quarter of the time that would have been required for a complete re-render of the image. Potentially, life-saving functionality indeed.
- Using the new UI elements, Quick Settings, and revamped Frame Buffer
- Understanding color mapping modes
- Adding V-Ray light types
- Working with the V-Ray Sun and Sky systems and dome light
- Using irradiance mapping and light cache
- Working with diffuse color maps
- Making reflective materials
- Creating a translucency effect
- Using the new SSS and skin shaders
- Ensuring quality with image sampling
- Working with the adaptive subdivision engine
- Controlling the physical camera
- Working with FX tools such as VRayFur and VRayMetaball
- Stereoscopic 3D rendering
- Using Render Mask
Skill Level Intermediate
Q: This course was updated on 02/02/2016. What changed?
A: We added tutorials on the new 3ds Max camera tool, which replaces the defunct V-Ray Physical Camera. The author also includes a method for creating a V-Ray camera via scripting.
Q: This course was updated on 04/19/2018. What changed?
A: New videos were added that cover V-Ray 3.1 to 3.3 updates.