Hi guys :)

I’ve a question for you.. there is something strange in a work that I’m doing (and I don’t succeed to find a solution).
This is the screen:

Well, when I use “bevel” on the edges of this object I have strange defects on the surface, as you can see, and this problem appears in rendering, not only in viewport.

The object is really simple: I’ve tried to use weld, to eliminate some of the edges… but nothing! The only thing that I can do is to use “HardEdge” on the edges that I’ve to bevel but it creates discontinuity on the surface… (I’ve tried to modify also the values of discontinuity)

How can I do it? There is something that is not as I think it should be…

Well, thank you in advance :)

it’s quite common, happens because the object is low poly (has only one big polygon in the area where the problem appears)

You can redo the object with more polygons and after you bevel the edges you apply a smooth operator or you can use hard edges as you said or you can just duplicate the polygons that have this problem using CTRL+D but the result is similar when using hard edges.

I found today a temporary solution to this annoying problem.

The concept is to close the artifact in a little space, near the bevel. If you build an outline edge around the bevel, the artifact disapperar on the surface.
However, creating edges would be annoying and would slow down the workflow, especially with more complex objects.
So, I found this process:

- Select the Edge you want to bevel
- Right click and select Disconnect Components
- Bevel the edges just a bit more than desidered radius (this operation creates the outline I’m talking about)
- Now, select all the Boundary Edges and Weld them together.
- With the Edges still selected, Bevel them, now with the desidered radius.

Now, your model sould be correct

In this way, you don’t need to rebuild the model or made it too heavy applying tassellations. Even more, this way don’t stretch or spoil your texture projection (if the model already have it)

I’m not able to write a script to automatize this solution but I think it shouldn’t be so hard to script.
Anyone could script it?

Another way to solve this is to select the polygons which are badly shaded and run an Inset Polygons operator on them - creates extra polys but gets rid of the shading issues.

Adrian; it’s not just because it’s low poly, if you get your geometry right you can build beveled objects like this without adding much, if at all, to what’s already there.

Charlotte, either the inset poly solution, which will keep you a nice, smooth bevel, or mess with your automatic discontinuity settings, which may not keep things smooth on the bevel.

Quick explanation why; think about how flat polys on a sphere appear rounded. Same thing.

I’m going to write an article about this, it comes up a lot.

Hey guys, this is how i would go about this, I think the problem here Charlotte is the way you have built the geometry.  As said previously insetting the poly’s would help anyway I’ve done a little picture to illustrate.  But as with everything in 3D there is a dozen ways of skinning a cat (or polygon!) So I’m not saying this is the best way but its straight forward.

cheers

or you could use the TinyThickness -www.kim-aldis.co.uk -tool to add the depth and bevels. It has a ‘fix’ button to fix top face shading curvature.

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wow.. thank you guys! there are a lot of suggestions..! Thanks kim aldis for your explanations :) I’ve tried Loki’s method and the method of the inset. This one, indeed, resolves the problem of the shading but at the same time it creates problems on the objects that are already mapped. Instead, the method that Loki has recommended works well, also on the objects that are already mapped because it doesn’t create stretch on the texture projections. This is a screen.. in this way you can see the differences:

This is an interesting thread as a bevel is one of the simplest features to add to a model. However, it can prove tricky.

I have to say that an even more challenging bevel is window within a curved surface such a a sphere. I have tried many ways to obtain a clean surface and the best I have found so far is using Kim Aldis’ TinyThickness plug-in.

Also, a large amount of geometry helps as well.

One, thing always puzzles me is how do you quickly reverse or alter a bevel when modelling. I find it difficult to regain the original surface.  Any thoughts on this issue?

Regards,
Alan

In fact the inset method still isn’t quite right; shading on the longer bevels is still getting pulled out by their neighbours on the corners.

A trick, which I’ve not seen used for the best part of 20 years, is to flag surfaces which will be removed from normal calculation on other faces. Using this method you can get nice small rounded edges with only one face. This would require a custom operator but it does work very well

It’s a very interesting thread.

I’ve got problems with bevel too. I know there are many ways of doing something but what do you advise for modeling mechanical parts:
1) use sub-d and add many many geometry to keep it’s almost-hard edges
2) play with geometry aproximation, lower the angle value at which normals start to blend together and try to adjust angles on bevels
3) turn of (in geometry approximation) blending of normals, the geometry will be very hard and then add many bevels in places where I need to make some round corners

I’m modeling simple space ship and I can’t make some surfaces look like made of steel, flat but with subtle bevel around some edges.

Can’t attach images right now.