Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => [Max] Resolved Bugs => Topic started by: refa on 2014-04-14, 13:20:22

Title: Weird thing on Sofa
Post by: refa on 2014-04-14, 13:20:22
Hi all. I don't know how to describe my problem, but if you look at the surface of the sofa in the scene, there are few weird spots which left me clueless as to what it is and what cause it to happened.

I'm new to corona, and at the moment I'm pretty lazy to model my own scene just for that first test, so that's why I took the scene from the A4 Benchmark. I import the .obj file in max, and apply my own simple materials and lights setting to immitate the A4 Benchmark scene.

I attached together the material setting for the sofa. Render settings are left to default. Anyway, it was rendered at 4K for 7.5 hours with dual xeon, but single thread. Thank you.
Title: Re: Weird thing on Sofa
Post by: Ondra on 2014-04-14, 13:25:12
Can you post the environment tab in settings and the material on the plane behind window?
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-14, 14:41:14
Thanx for the fast respond, here's the settings.
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-14, 14:51:19
Sorry Keymaster, I misunderstood your request. Here's the environment tab in the render setting =)

Edit: I emailed you the scene file to keymaster@keymaster.cz hope u received the mail. thank you
Title: Re: Weird thing on Sofa
Post by: Ondra on 2014-04-14, 16:09:38
Note to self: file 3D_001.zip
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-17, 02:15:03
Keymaster?...
Title: Re: Weird thing on Sofa
Post by: Ondra on 2014-04-17, 09:27:38
refa?...
Title: Re: Weird thing on Sofa
Post by: romullus on 2014-04-17, 10:52:28
Keymaster?...
Since this scene isn't your creation anyway, you can put it on forum, so somebody with more experience would pick it up and take a look at what may be causing a problem. There's no need to waste Keymaster's time with "bugs", that most likely are inexperient user's fault.
Title: Re: Weird thing on Sofa
Post by: Ondra on 2014-04-17, 13:22:16
I will take a look at it eventually, right now I am busy implementing another important and big feature.

BTW: posting the scene here is not ok without the consent of its creator (Rawalanche)
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-18, 01:06:47
posting the scene here is not ok without the consent of its creator (Rawalanche)

That's what I thought in the first place. Thanx keymaster, I'll be patient.

you can put it on forum, so somebody with more experience would pick it up and take a look at what may be causing a problem.

Thanx romullus, that gives me an idea. I'll find a free time to model my own simple scene, merge in the same setting for lighting and materials, but without the same texture used by Rawalanche, and see if the same prob occurs. If so, I'll post and share the scene here. Thank you everyone.
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-19, 13:55:42
Hi everyone, for the purpose of the exercise I've come out with a scene, pretty much a copy of the original scene by Rawalanche. I don't know why but I have to copy the original interior layout to match the light-bounce. I don't think it's that important, but at least it discount one of the causing factor of the 'weird thing on sofa'.

I don't know the actual cause of it, but I can see that after rendering the sofa with various type of materials, I found that reflection cause it to happen. I can settle down with a reflection-less sofa, but for the purpose of debugging, I welcome anyone to come out with a solution of how would one use a material with reflection in such scene.

Here's the scene > https://drive.google.com/file/d/0B_ztQJVjoF_JdG9oc0R1YTgwVjg/edit?usp=sharing

P/S: Sorry for bad English. The whole scene is hand modeled by me, so there's no copyright infringement, I hope =). Thanx Rawalanche.
Title: Re: Weird thing on Sofa
Post by: romullus on 2014-04-19, 14:49:59
I looked briefly at your scene and discover that it was your glass material, that causes such weirdness. Your glass pane object has no thickness, yet material is set to solid. You must either add shell modifier to glass pane or set glass material as thin.
Nevertheless your scene contains many errors and wrong setups (enviroment, materials, geometry). I don't have time to look more closely at it, but i'm sure, someone will do it and will upload corrected scene here.
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-21, 14:19:06
Thanx romullus.

I set the glass material to thin and that solves it. But when I uncheck the thin option, and shell the glass plane instead, the same weird thing appear on the sofa. Why is that?. BTW,  what should I name/call this problem, for future preference. Thank you.
Title: Re: Weird thing on Sofa
Post by: romullus on 2014-04-21, 16:43:26
Well, there's something wrong with your scene. I got that bug too, when added thickness to glass. I merged all geometry into new scene, however, and bug dissapeared.
Now, few tips: don't use max's skylight, add CoronaSky map to enviroment tab, instead. Set diffuse level of glass material to 0. Keep CoronSun's intensity multiplier closer to 1.0 and adjust brightness of image with exposure in render settings (you can do that while rendering). Give your walls some thickness (with shell modifier).
Title: Re: Weird thing on Sofa
Post by: refa on 2014-04-24, 04:29:15
ic, thanx for sharing romullus, much appreciated. But walls need thickness? referring from the scene made by Rawalanche, the walls are all thick-less. and how does the wall thickness help in simulating light illumination (rendering)? illuminate me =)
Title: Re: Weird thing on Sofa
Post by: romullus on 2014-04-24, 09:00:34
Well, maybe there isn't absolute necessity in doing that, but it doesn't harm to develop good modeling habits ;]
Title: Re: Weird thing on Sofa
Post by: Ondra on 2014-06-22, 21:56:37
ok, this is exactly the same issue as https://corona-renderer.com/bugs/view.php?id=274