Join Brian Bradley for an in-depth discussion in this video Overview of color mapping, part of V-Ray 3.0 for 3ds Max Essential Training.
- Color or tone mapping is an internal process that V-Ray uses in order to map the high and low color values found in our rendered pixels. In other words, it effects the way in which the brightest and darkest colors will be represented. The process does indeed have a number of similarities to a camera's exposure control or even the response of the human eye to light levels found in an environment, given that color mapping is designed to map the colors rendered internally by V-Ray to a range that is both usable and viewable by the rendering artist.
Of course, color mapping in some form or another is something that all render engines have to do internally because without this final translation of collected information to usable pixel values, we wouldn't get anything pleasing in the way of images out of our render engines. One of the potentially useful things about the way in which V-Ray goes about things though is the fact that it allows us to make some pre-render choices regarding how the color mapping process will work. This ultimately gives us the ability to determine in advance, at least to a certain extent, how our final renders are going to look.
Now before we, in our next video, walk through a brief description and comparison of the color mapping types available in V-Ray, I just want to take a quick look in this video at some of the color mapping controls available. To do that, we will of course need to open up the Render Setup dialog and come into the V-Ray tab where we find the Color mapping roll-out. To be sure that we are seeing all of the controls available, I'm going to switch the UI over to Expert Mode because the very first option I want to quickly touch on is the only one that is found exclusively in Expert Mode, this being the Linear workflow switch.
Now, contrary to advice found in quite a number of tutorials and training videos, this is not an option that has to be enabled in order for us to work in 3ds Max and V-Ray using a Linear workflow. This switch was added by Chaos Group for users who wanted to open up much older V-Ray scenes and have them work correctly. In fact, if you look in the V-Ray Help file for this feature you will see why it now appears only in Expert Mode. The Help file says, and I quote, "This option is deprecated and will be removed "in future versions of V-Ray." Just be aware, then, that enabling this option does not give us a genuine Linear workflow when working in V-Ray and Max.
The defaults for both applications are already set up for that with no extra work being required on our part. Of course we will need to keep in mind that if we want to carry a Linear workflow into the compositing stage of production, then we will need to make certain that we save our V-Ray renders to floating point image file formats, such as .exr, .hdr, or .rpf. Another color mapping option I would like to touch on here is the Clamp output check box. When turned on, this option caps or, as it says, clamps pixel brightness values to the value specified in the numeric field here.
Enabling this will have an unseen and yet impactful effect on our renders. For one thing, any images such as the one that we have here containing very bright areas will probably render a little bit faster. This is due to the fact that fewer image samples will be required now that there are no super bright pixels in the image that need to be anti-aliased, assuming of course that we clamp our images to a value of 1.0. Now whilst using the Clamp option doesn't prevent us saving our renders to floating point image files, meaning we could still in post-production push the image exposure back into the super bright range, what we will have to keep in mind is the fact that clamping in V-Ray will limit the dynamic range or contrast ratio that our image contains.
Now as this may not be a big deal on some projects, there may be others where this could cause problems once we get into the post-production phase. The final option I want to quickly look at here is Sub-pixel mapping. This option controls whether or not the color mapping mode and settings that we choose get applied to the final rendered pixels in an image or to the sub-pixel samples from which the final pixel colors will be constructed. The difference in look produced by the two operations is usually very subtle, if in fact it can be noticed at all, although working with Sub-pixel mapping off is thought by Chaos Group to produce a more accurate looking final render.
One problem this option can, on occasion, help with is that of fireflies or bright speckles in a render that typically exist due to super bright areas receiving insufficient samples or rays in order to be resolved correctly. V-Ray 3, though, does have tools that are perhaps much more suited and more proficient at solving this particular problem as we will see later on in the course.
- 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.