Gaps visible between surfaces

[tauttvisz]

Why there are gaps visible between surfaces in my model? When shading is off everything looks ok, but when there is any kind of shading on, this happens.. Any way to fix this?

[ravenzep]

There is nothing to be fixed, in the sense that there is nothing wrong.

This is a feature of alias that is totally controllable, for for example when u have a lot of geometry on viewport and things become slow, so u reduce tesselation of objects so everythig is smooth. This is only a visual thing.

Anyway, go to the menu bar on top and chose OBJECT DISPLAY / DRAW PRECISION, and set it to say, 0.8. Now it will look a lot better. Right?

Another place where you can set this setting quickly is in your control panel (on the right).... Look for DISPLAY/QUALITY/DRAW PRECISION. Same setting as before in a different location. Set it to your preference. (0.8 values should work fine). This setting, is used to control your viewport display tesselation when using SHADE FAST (CTRL + RMB + SHADE FAST)

If you are using Diagnostic Shade toolbar, with multicolor shading, you will have a different setting for this, which is called tolerance, where you can set a value of 0.01 for example. This is just a different algorythm based on tolerance that does a similar thing to draw precision.

Hope that helped.

Have fun.

[tauttvisz]

Doesn't seem like draw precision would do anything, but it was set to 0,5 anyway. Tolerance though does work. Thanks!
Btw, maybe someone know how to render Alias models in Maya with V-ray? Geometry looks edgy, but this is only with V-ray, with Mental Ray geometry looks maybe not perfect but much better. 

[ravenzep]

Precision does the same for shading fast. The other method is a different thing.

Tesselate your models in alias with nurbs to mesh, before entering maya, and u ll have polygons.

Maya has a Approximation editor for this sort of things, but it s crap, and i never liked how it works.

[tauttvisz]

I was hoping to keep everything in NURBS. Doesn't tessellation to polygons mess up the geometry a little bit? And overall polygons without smoothing don't look good. I mean in Maya for smooth effect you use smooth preview (or whatever it's called, when you press 3 on your keyboard), but you can't really use it with converted geometry. Isn't there a way to render NURBS geometry? How do they do that in automotive and other products industry?

[ravenzep · Accepted solution]

Nah, it is not like that. You can define the level of tesselation you want, and it does not mess up anything at all.

You can retopologise if you want in maya too.....Which is doubling the work.

And you can use VRED or Keyshot, which is what i use, which will treat any nurbs geometry very very well, for rendering.

I would never render anything in NURBS in MAYA, no way. The cars you see in comercials are rendered in polygons, and most houses retopologise the nurbs data from manufacturers into polygons, with maya brilliant tools. That s the usual workflow, they dont render from nurbs, if using maya. Been there done that.

That 3 key  you are talking about, which is a non-persistent  mesh smooth, has nothing to do with it looking good or not. Actually i never use subdivision  surfaces when modeling in polys. what makes them look good or not are the NORMALS. Say, if you imported something into maya tesselated from alias, you dont apply subdivision in maya at all. That is a no way. Instead  you should achieve the level of desired tesselation in alias itself. I assure you it gives you insane dense meshes, so you need to strike a balance there. Use the option VISUALIZATION, in case you tesselate from alias, which yealds better results for rendering purposes. Like I said, and personally, the best workflow for rendering alias stuff is just to use one of the 2 render softwares i mentioned. Very fast workflow with no hassle and excellent output.

Hope that helped.