Join Joel Bradley for an in-depth discussion in this video Relaxing UVs, part of 3ds Max 2018: Mastering UVW Mapping.
- [Instructor] To help us take a look at the Relax tools inside the UV editor window, we're going to work in this exercise with a slightly different portion of our robot geometry. Now we have, up to this point in our course, already made use of the relax tool a number of times, but, what we haven't done is explained just how the controls actually work. If I go ahead then and open up the UV editor window, we can see that once again we already have an unwrap solution in place, courtesy of 3ds Max's pelt mapping tools.
Clearly though, the end result, as seen in the view port, leaves a little bit to be desired. In there, we see quite a bit of squash and stretch going on in the task map. To clean things up then, let's jump into polygon sub-object mode. And just to make things a little easier to see, and with the element toggle turned on, let's select the single cluster that we have here. What we want to do then, from the tools drop down menu, is open up the relax dialogue. Now the first choice that we need to make here is to decide which of the relax by options we want to use.
As you can see in the drop down, we can choose to relax by polygon angles, edge angles, or even by centers. With each option producing different relax results. Relax by polygon angles relaxes the vertices in the UV mesh based on the objects polygonal faces themselves, trying to align the shape of the UV face to the geometric face on our model. This algorithm is being designed mainly for use when trying to remove distortion rather than overlap. And it's best suited for working with simpler shapes.
In my personal experience though, this option can often times cause fewer problems and give cleaner results, even when trying to deal with overlap issues. Relax by edge angles is the default option and works in a manner similar to relax by polygon angles, except that it uses edges attached to vertices as the shape it tries to match, rather than the polygons. Final option, relax by centers, is essentially the legacy relax algorithm first put into 3ds Max, and so may not be the one that we use too often.
In terms of the settings that we see in the dialogue, we have iterations option that controls the number of times the amount and stretch values are applied to the UV mesh. With each and every click of the apply button, we will add an iteration to the previous set of results. In other words, each time we click apply, we stack the resulting relax operations one on top of the other. The usable range here goes from zero to 100,000, with the default being 100. The amount option controls the strength of the relax operation as applied per iteration; with 0.1 being the default inside a usable range that this time goes from zero to one.
Stretch, naturally enough, controls the amount of stretching allowed to occur inside the relax operation. Introducing stretch will mainly be useful when trying to resolve overlapping texture vertices. Be warned though, adding this can often times reintroduce some distortions to the UV mesh. The range, as with the amount option, goes from zero to one; with the default, this time, being zero. To smooth out the mapping problems that we see in our viewport, let's select the by polygon angles option from the dropdown, and in this instance, leave the iterations value alone.
Given that we're going to be using the stack relax, rather than apply button. This applies the relax algorithm as an ongoing process, rather than a single application. And so doesn't need to use the iterations amount. In terms of the amount, our strength of the relax operation a fairly straight forward uv cluster such as this, I tend to apply a bit of brute force using a value of one. Although, when working with more complex UV clusters, it is probably advisable to start testing using the default of 0.1.
Finally for the stretch value, I will, in this instance, go with the default and leave things set at zero. Clicking the stack relax button, as we said, applies the amount and stretch values set here as an ongoing and continuous operation that will refine and adjust the relax solution, really for as long as we leave it running. As this is a very simple UV mesh, we achieve a finish solution fairly quickly, and so we can hit the stop relax button when we feel it has relaxed enough. Once done, if we de-select everything we can see the mapping in the 3ds Max view port which shows that we have now created a much cleaner, and more uniform final mapping result.
Instructor Joel Bradley explains what UVWs are, how they affect textures, and why they are needed. He also reviews the different mapping spaces that are available and how procedural maps are used in texturing. Then he progresses to the hands-on portion of the course, starting with mapping simple shapes and models with the UVW modifier. He also reviews advanced topics, such as unwrapping and editing UVs with the UVW Editor. Finally, he introduces blended box mapping, for when you need to get a model ready for texturing quickly.
- UVW coordinates
- UV space
- Working with the UVW Map modifier and UVW gizmo
- World space vs. object space
- Peel mapping and pelt mapping
- Reshaping UV elements
- Smoothing and relaxing UVs
- Rendering UV layouts
- Blending seams with the Blended Box Map