Raytraced bug: edge softening

Edge softening gives an odd shadow line along the edges:

And if I move an object to a layer that has no material assigned then the previous material appears still assigned to the object. Until I either assign the layer a material or swap to an other display mode and back again.

Edge softening gives crappy render mesh. I understand edge softening is supposed to be a visual gimmick. For proper results you should use fillets.

Unless you can convince @andy and @davideranen to make it give better meshes… :slight_smile:

The material part I’ll test later.

Well, the odd thing is that extracting the rendermesh and then unweld at 0 and weld at 180 gives a much better result, so I think it should be able to handle it better out of the box.


I agree it should do better. Incidentally we discussed this exact problem this morning in our office:-)

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Indeed! However, getting edge softening to work has value as follows:

Since Rhino is weak at fillets, often not an option inside Rhino. Must go to MCAD app to get the fillets in without failure. Boohoo.

Now that the data, with fillets, is outside Rhino, might as well render outside too, i.e., Keyshot, etc., as opposed to re-import with fillets. Especially when rendering simply for design evaluation. This whole ordeal is rather inefficient, though.

Played, briefly, with V6 WIP and Cycles. (focused on MacRhino) Has promise, especially for nice RT photoreal views, while designing. It is a lot slower than Keyshot to come into enough focus to move on, but staying in Rhino is a lot faster than moving to KS just to have a photorealistic look at design progress.

To avoid the aforementioned hoop jumps, and when fillets fail, functional edge softening allows one to remaining in Rhino when desiring an accurate look at progress. Valuable. Obviously, such is perpetual and ongoing.

Make sense?


I would be glad to see improvements of edge softening too. It’s a powerful, often used here. A great helper for rendering.


We have created a YouTrack item to keep track of progress on this issue:



Hi Nathan, I am pleased to say that WIP is so stable now that I dare use it in work scenarios and here is an example on why edge softening is important.

This sketch consists only of simple shapes with edge softening on it, that makes it very easy to scale the objects in both 3D and 1D and still get the same edge smoothness on the parts.

Edit: …hmm. image pasted as pure white so here cut and pasted with windows sissor tool.

There are multiple hickups that needs to be ironed out, but getting good results are easy and this image took 51 seconds to complete with 250 passes. 250 gives good enough results for this scene even in shadow areas.

Here you can see the difference between edgesoftening:

and fillet:

So if it is possible to make cycles handle edgesoftening nicer, withougt the dark line, then that would be very welcome.



Good news Holo, I improved edge softening a bit yesterday. It should look better in next week’s WIP. It’s still not perfect though, especially if the radius is large and the object close to the camera.

Keep in mind that the main purpose for edge softening is to add small highlights, not do actual filleting.

Here’s a peek at a large radius softening (not recommended) before and after fix.


Cool. Keep banging on each part of Raytraced, and report it. Together we make it great (:


p.s. I am working on merging upstream Cycles up until 2nd of June. Many improvements!

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Correct! At some point in the development process real fillets need to be inserted.

Edge softening most valuable during early design process when, for whatever reason, filets are not yet present. Especially with Raytraced mode, where the designer seeks active, realistic, in progress feedback efficiently, and where rendered knife edges are counter to realistic.

Thanks for the attention to this.

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RH-39563 is fixed in the latest WIP