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Use Constraints: Maya tool I believe everybody should be using!

insane polycounter
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Ashervisalis insane polycounter

Hey all, I wrote a blog about this tool (https://www.artstation.com/thomasfraser/blog) for Maya. I've told a bunch of people about how it can speed up their modeling but it's falling upon deaf ears. Use Constraints is extremely handy when you want to choose edges, verts, or faces which have specific properties.

Selecting edges for beveling or UV cutting

Here is an image of a simple model I've created. Whether I want to bevel all the hard edges, or cut them for my UV mapping, I'd like to select all of them in just a few button clicks, instead of manually selecting each hard edge/edge loop one by one. To do this, open Use Constraints (Select > Use Constraints) and you'll see the below window pop up. I have this docked as I use it frequently.

Right click on your model, and select 'Edges', and you'll notice your Use Constraints menu might change. The menus for constraining for verts, edges and faces are all different. Next, click on "All and Next", and "Hard," and all of your mesh's hard edges will automatically be selected. This of course is extremely handy the more complex your mesh becomes.

Use Constraints to select edges which should be hard

Sometimes my model is an ugly mix of hard edges which should be soft, or soft edges which should be hard. Below, I've just softened the entire model instead of going in and fixing each incorrect edge one by one. But I would like all 90 degree corners to be hard!

You're going to need to turn off the Properties - Smoothing selection so as you can select all edges. Open the 'Angle' menu, and click on 'Activate'. Here, play around with the minimum angle requirement, and bringing it to 90 degrees will select every 90 degree angle on your mesh! Now I can simply harden or bevel these edges, and it only took a few clicks.

I'll point out that sometimes I've left other constraints on, such as trying to constrain using an angle, but also had the constraint for hard edges activated, and it has caused frustration a lot. If Use Constraints is not working properly, scroll through your menus to see if you have any other constraints activated which you can turn off.

One of the more useful situations to use this tool in is after decimating a mesh from ZBrush (as below), as the mesh is now triangulated, and selecting edge loops is now impossible. It is a complicated mesh for sure, and I'd like to cut the UV up based on the cavities of the mesh. After playing around with the angle settings, I've been able to find an OK setting for my constraints. I will, however, need to spend a little bit of time cleaning the cuts up.

 If you have any tips and suggestions, I'd love to hear them!


  • onionhead_o
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    onionhead_o polycounter lvl 12
    thanks for sharing the info. Haven't had much luck with the angle option but its nice to know it can be used in that way. I use the Select Contiguous Edges mostly for hard to select edges for triangulated meshes. Also the new 3d cut and sew tool is quite handy, it does shortest distance and grow loop as well. But the most useful one i find is the cut loop which will stop on existing uv borders.
  • Alex Javor
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    Alex Javor insane polycounter
    Cool thansk for sharing.

    I want to ask though, in the picture staircase mesh, is it common practice to take something like that into game? For enviro artist? Seems like inefficient topology. I realize retopo of that isn't going to be fun, but it shouldn't take more than 20-30 mins to get a much lower tri count with UV's that can be easily and cleanly unwrapped. Also could have nice topo in case you doing tessellation. I'm asking though cause i remember seeing in naughty dog art dump they had some polygon soup modular enviro pieces, but nwo that I doing a little enviro art I can't see the reason for this. Purely for speed?

     I would also recommend becoming very familiar with convert selection tools and marking menus for this as it can speed up workflow dramatically. If you feel like you have to manually select many edges, tehre is much faster ways to do some with in-built tools already.

    Personally I set convert to quad/edge/face to the 1,2,3 keys. Usually if you trying to isolate certain parts it can be very fast by selecting by another component and then converting. Combine this with paint select, lasso select, and camera based selection and basically being able to select whatever you want within a second or two should usualyl be possible.

    (not saying this isn't worthwhile tool, I gonna check it out myself for a couple of the things you mentioned, but some people may not be keen on third party stuff and if they can increase speed using inbuilt tools thats always good too)

  • Ashervisalis
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    Ashervisalis insane polycounter
    @Alex Javor Hey, this isn't third party stuff, this is already built into Maya! The decimated mesh is all up to the pipeline and limitations I guess. If you're sculpting a bolder, it doesn't really need to have property topology. If decimation master can get you to the desired poly count, and do it in a few seconds, why not? I'm not going to spend an hour re-topologizing a jagged bolder. But alas, you know how 3D artists are, there are going to be people with differing opinions on the matter!
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