Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => [Max] Resolved Bugs => Topic started by: pokoy on 2016-07-14, 10:14:04

Title: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-14, 10:14:04

The latest 1.5 DB shows some problems when SSS is used, see attached images. When using SSS the material displays facets, this didn't happen in 1.4.
Also, it seems that SSS is slower, mostly noticeable using maps in diffuse/reflection etc channel. Displaying a simple material preview takes 4 seconds with some maps for example, with SSS enabled (setting Absorption distance to >1) the time it takes to display the preview doubles.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-14, 11:00:37

Sorry, forgot to add that the facets only appear when using SSS with refraction, using fraction only works fine and doesn't show them, it's also rendering faster than with refraction.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: maru on 2016-07-14, 15:06:37

I don't think the faceting is something new, see:
https://coronarenderer.freshdesk.com/support/solutions/articles/12000012390-my-sss-objects-are-faceted-

But it would be great if you could check if there is any difference between the newest daily and any other builds (1.4? 1.3?) nonetheless.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-14, 16:27:49

Never came across this, probably because I didn't care to open the material preview in a bigger window - my bad.

Still, I'm seeing slower update times if SSS is based on refraction... I'm quite certain this was not the case before.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: Ondra on 2016-07-22, 16:41:14

Can you provide a scene/material sample where a significant difference (either in quality or speed) happens?

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-22, 17:08:29

This happened on a fresh simple scene, with a sphere with an SSS material - nothing complicated really.
The difference was noticeable between the two SSS modes - fraction and refraction - where the refraction mode was the one that took longer to update and render.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: Ondra on 2016-07-22, 17:17:09

still though, without solid evidence, there is no bug. It is perfectly normal that the different modes render differently, I was under the impression that it was not the case before - that would indeed be a bug

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-22, 18:44:18

Quote from: Ondra on 2016-07-22, 17:17:09

still though, without solid evidence, there is no bug. It is perfectly normal that the different modes render differently, I was under the impression that it was not the case before - that would indeed be a bug

I didn't test against 1.3, and as you say no hard evidence, more along the lines of 'this used to be faster'.
Maybe move to post to resolved and I'll keep an eye on this and report back once I have a more solid impression.

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: Ondra on 2016-07-25, 11:29:13

yep... it is nothing personal, just my experience that "feeling this used to be faster" disappears when compared with older version ;)

Title: Re: 1.5 DB 13-7-2016 - SSS Artifacts and slowness
Post by: pokoy on 2016-07-25, 12:34:28

Yes, probably safe to assume it's in the same category ;)
Thanks!