Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: krassihg on 2015-06-04, 05:46:47

Title: Strange Corona behavior
Post by: krassihg on 2015-06-04, 05:46:47
Hello,
I am new to Corona, it was working fine until recently. I made several render iterations of a scene and it was working just fine, and then on the next attempt to render, it started to fill the whole field of the render scene with those green dots, like it is rendering something else. Usually I can see the rendered image  after several seconds, but this time it takes forever and I didn't make any changes that could do this effect. What is going on?
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-04, 06:18:33
OK, so when I moved my view point away, to see a bigger picture, I see this. A "cloud" of green dots, very intense around the main objects in the scene. This cloud appears as a solid field of green dots when I am closer, like I am inside the "cloud".
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-04, 06:35:37
I changed Max Ray Depth  to a value 2, and that green "cloud" cleared faster, so I can see what is rendering, but it has nothing to do with the geometry of my scene...there are some weird planes crossing in space etc, but nothing of my objects. It was supposed to be an underwater scene, and it rendered fine before. I attached the current render and 2 previously rendered images.
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-04, 07:03:20
I deleted all lights, created a new scene and imported the geometry only, created a new Corona Sun and try to render. This is what I got...a jungle of entangled weird shapes, nothing like my little boat under water scene. ??? Any ideas?
Title: Re: Strange Corona behavior
Post by: romullus on 2015-06-04, 08:55:25
Does one or several of your materials use displacement? It could be set to wrong scale.
Title: Re: Strange Corona behavior
Post by: maru on 2015-06-04, 10:30:36
My guesses would be:
-damaged file
-bug
-displacement as Romullus suggested (though not likely - your displacement settings are high and this is low-poly)

One idea:
That strange geometry. It has a material. To what objects is this material assigned? Could you select these object/s by material and isolate them?
Title: Re: Strange Corona behavior
Post by: Ondra on 2015-06-04, 11:20:29
For the record the first images are UHD cache precomputation visualization
Title: Re: Strange Corona behavior
Post by: PROH on 2015-06-04, 13:13:22
Hi krassihg. Just to understand you correct: Are the two images "test3" & "test4" rendered with Corona? The reason I ask, is that if you haven't seen the "green cloud" before, then it doesn't sounds like they are rendered with Corona.

BTW - What Corona version are you using?
Title: Re: Strange Corona behavior
Post by: Rimas on 2015-06-04, 13:24:24
For the record the first images are UHD cache precomputation visualization
+1 I see this all the time. Green seems to appear on reflections/refractions primarily.
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-04, 23:59:05
Corona version:   Corona version: 1.00.02, Maxsdk version: 2015

Yes, all images are Corona renders.I just publish them for reference, as I said, they rendered fine the first several times.That is what puzzled me , because it was just  fine in the beginning, and I did not made any changes to the render settings. I played with the materials, yes, I was trying to get some caustics effect , but then I just plugged in a map in the refraction slot of the water surface material. I suspect the file is damaged, but what bothers me,is that the rendered geometry does not appear damaged before the render starts, only after a while. This is the first time I see this kind of monstrous deformation .
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-05, 00:02:28
@Maru
I can't select the material of that rendered crazy geometry, because it does not appear in my file ( model). It only appears after rendering.
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-05, 01:53:03
Two more images. You can see the scene in the perspective view port, and you can see what is rendered in the Corona Virtual Frame Buffer. I looked for a hidden geometry, nothing..this is all . A plane and a model of a ship.I deleted sea surface above.  One sunlight Corona. It keeps telling me that there is a second Sunlight and it will be ignored. I checked the materials for Displace maps and got rid of them. It still renders this nonsense.
 I will keep experimenting to find out what it is. The thing is, initially this model has been set up in Vray environment, then I imported it in this new file, it was giving me warning for a missing Vray dll or something, but I don't think it is affecting it, because it was rendering fine the first several times. I think it started doing this after I decided to use the global volume material, but I am not sure if this is the reason. I just wonder if other users have experienced something like this. Eventually I am trying to find out is it originating from my computer or setup, or it is a bug of Corona. I love Corona, by the way.
Title: Re: Strange Corona behavior
Post by: Rimas on 2015-06-05, 08:17:06
Have you tried resetting Xform of the model? Could potentially be a vertext scale/transform issue if it's an imported model. Just a hunch.
Title: Re: Strange Corona behavior
Post by: maru on 2015-06-05, 10:39:22
@Maru
I can't select the material of that rendered crazy geometry, because it does not appear in my file ( model). It only appears after rendering.
If it has a material indeed, you should be able to go into material editor, click get material, scene materials, and look for it (greenish thing).
Have you tried deleting objects one-by-one and seeing when/if it disappears?
Have you tried merging this scene into a new one?
Title: Re: Strange Corona behavior
Post by: juang3d on 2015-06-05, 12:23:12
One test you should do is to hide your boat, put a teapot of the size of your boat, and render it, put a default corona material in the teapot, untouched, this will tell you if the problem is in your shaders or in something else in corona, or in your geometry, but for what is worth, I think you have a problem with your shaders/geometry, as Romullus said, do you use displacement in any shader?

Cheers!
Title: Re: Strange Corona behavior
Post by: krassihg on 2015-06-09, 03:53:06
OK, thanks for the suggestions. I test it with the teapot, it rendered good. Then I did apply one default Corona material for all the geometry, and it rendered fine, so it must be some of my materials that is the culprit. It is amazing how a wrong material can create such a mess.
Title: Re: Strange Corona behavior
Post by: romullus on 2015-06-09, 08:21:15
I checked the materials for Displace maps and got rid of them. It still renders this nonsense.

To be absolutely sure that it's not displacement, go to Render Settings -> Common tab and uncheck displacement option.
Title: Re: Strange Corona behavior
Post by: maru on 2015-06-09, 10:04:47
This looks like a corrupted file or something similar. No chance to upload a file where this happens? Have you tried hiding objects one by one, to see with which object this is connected?
Title: Re: Strange Corona behavior
Post by: Ludvik Koutny on 2015-06-09, 10:12:19
My bet would be displacement too.