Topics

1

[Max] I need help! / Strange behaviour when exporting EXRs (Corona 4.0 issue?)

« on: 2019-07-05, 10:10:52 »

Hi Coronauts,

We have come across a strange issue when opening EXRs that have been rendered in Corona 4.0. At least it seems to be related to 4.0, as we had no similar issues before.

Descripton:

My task is to render a set-extension for a photographed set (large wood beams on the ceiling).
No problem so far: camera-matching, light-setup, shadow-cather - everything worked as always and Corona's IR makes it very easy to see if what I was doing acutalley feels right.

However, when I finally rendered the Hi res version as CXR, wrote the EXRs from the CIE and then loaded them into PS, they looked wrong colorwise. Not completely wrong, just a little bit off.

You can clearly see the seam where the wrong color of the EXR meets with the real image. The real image has a lot more red in it and seems to have a bit more punch:




No matter what we tried (writing EXR directly from VFB, using different PS-versions and setups, renaming CXR to EXR), nothing solved this problem.

The only "usable" workarounds are: using JPG (which is obvously not an option) or using the CTRL + C option from whtin the VFB in order to copy the image directly into the photo.

This is how it should look like:



The strange thing is: GIMP does handle these files very well.

So the problem might be related to Photoshop, but it is unclear in which way and since these problems only occured since Corona 4.0, there  also might be some causality on the Corona-side.

Has anybody come across a similar problem so far? It is really strange und we did not change any of our PS-versions or settings...

2

[Max] I need help! / Corona 3.0 Displacement Artifacts

« on: 2019-03-05, 10:09:08 »

Hi Coronauts,

in our company we just upgraded to 3.0 (including Hotfix) for 3ds Max and ran into an issue regarding the new displacement.
I tried to find a solution in the forum, but did not find any.

We always use chamfered edges on our walls in order to make them more realistic.
When using displacement, these chamfered edges will become the typical distorted geometry known from older methods of displacement.
I attached some images to show what exactly I mean.
I do not recall this issue from any project we did with 2.0.
So far this problem occured in two seperate scenes with different kinds of geometry, so it might be safe to say that it is a general problem.
Is there a quick fix for this problem?

3

[Max] I need help! / Output-gamma cannot be changed

« on: 2017-01-25, 14:24:12 »

Hey Corona-team,

as we do not make heavy use of render-elements anymore since using Corona, we did not bother much with making sure that all of them come out completely correct.
As of today we wanted to use the Reflect-element for composing and noticed that its gamma-value was not 2.2 but 1.0 despite having a working 2.2 in the Beatuy-pass.
Afterwards we became sceptical and noticed that only the Beauty-pass had the correct 2.2, all the elements have 1.0. This is just an issue when using the "save"-button of the Common-tab in the render-dialogue.
When saving the files directly from Corona VFB, the Gamma-value will come out correctly.

I tried different things concering the Gamma-value (using values of 4,4 in display, input and output gamma in the max-ini, disableing Gamma completely) but the phenomenom strangely stays the same:
The Beauty-pass has a working 2.2, the elements only 1.0, just like it would not be affected in any way by the modified Gamma in the ini-file.
It is very strange and I wonder if something gets overwritten by Corona internally, so that this happens all the time...


3ds max: 2017
Corona: 1.5

4

[Max] Resolved Bugs / [feedback] Corona VFB switches to black

« on: 2016-11-29, 10:22:28 »

Hi @ all,

I have encountered a strange behaviour in Corona 1.5 (1.5.1 and 1.5.2) with 3ds max 2017 SP 2.
I rendered a Hi-res image (4900 x 3500 px) and when starting the render process everything is fine. After 30 passes or so, some of the render elements (including beauty, lightmix and reflect/refract) turn black. When scrolling through the elements, they will be visible again, but will disappear after a second or so. When I try to save the .exr files, they will turn out completely black. I hoped that it would be just a display issue, but the image itself does not contain any information except black.

I already made a completely new file, tried it only locally, with DR and via backburner, it is always the same. There are only Corona-compatible cameras and materials inside the scene and the camera is not occluded by any other geometry.

Any ideas how to fix this? I did not encounter anything similar so far

5

[Max] I need help! / Strange behavior when rendering interactively

« on: 2016-09-30, 09:38:32 »

hey guys,

I am writing regarding a strange issue we came across during the last two productions, both times we encountered the same behaviour.

The situation:
In our studio, we do ArchViz (using 3ds max) and use a lot of High Poly props (Some scenes have around 15,000,000 polys in just one room).
So far, Corona could handle even this amount of polies even in interactive mode (and sometimes even with Hair and Fur enabled). Of course it took a while to get an image, but it was okay working this way and of course it is much better compared to Vray (we did not even bother using RT there, it was just too slow).

In the last production, I had to visualize a room with a lot of clothing. After merging a certain type of 3d-model from our stock (some T-shirts), I could not use Interactive mode anymore. Well, I could still press "Interactive" and Corona tried to start it, but no image came up. I looked at the task-manager and noticed a strange bahaviour (you can see a screenshot attached). Basically the processing power and the RAM go up and down, but the CPU never reaches a constant high, like when it is rendering. At the time I blamed the 16 GB of RAM and simplified the scene until I got it working again (that was not very fun, I had to check every prop, until I found out that the T-shirts were causing the trouble). The strange thing is, that the T-shirt material seemed to have caused this, although it was not very complex. I created a new one from scratch and this one worked again.

Anyways, yesterday we got an upgrade from 16GB RAM to 48 GB RAM and I was eager to see if I could get this scene working now. But still, it was the same issue, just without the Corona-warning, that I am running out of RAM. My collegue also encountered the same behaviour in another project which was completely unrelated to mine. If this problem was just on my machine, I would have blamed it on the file, but in this case, I am starting to get a little nervous. Is this something, anyone has come across so far?

We are using 3ds max 2017, newest SP and newest Corona Daily Build.
I also checked the file in 3ds max 2016, Corona 1.4, same problem...

6

[Max] I need help! / Corona AO Geometry issue

« on: 2016-03-16, 09:41:36 »

I have been working with Corona for a while now and usually I was able to solve most of the problems by searching the forum or trying things myself, but now I have an issue I do not understand.

I want to use CoronaAO to combine two materials. I used "Invert normals", to get some kind of used edges-look. As soon as I touch the Color spread option to get a more defined look, the AO starts appearing on literally every edge of the mesh. It also stays that way when using a texture in the Max distance slot. The geometry is low-poly with a Turbosmooth. I attached a clean test-scene render and even there it is visible. What am I missing? Is it normal that Color spread causes this effect or is there any way to get rid of it?

7

[Max] General Discussion / Corona Light Selects

« on: 2016-01-22, 09:38:39 »

Hi @ all,

there has already been a topic regarding this, but it has been dead for a long time, so I figured I might start a new one with a little more in-depth-discussion.

I am talking about the LightSelect-renderelements, which a lot of you might know from Vray.
For evereyone who does not know: It is a renderelement, which contains the direct illumination of a light-source (and just the light-source, not all of the lights combined).
It is useful for adding more light in Post-production, without altering the image as a whole.

I realised 3 projects in Corona so far and due to the very nice Interactive Rendering, we managed to set the intensity of the lights already in 3ds max, so that an adding of more illuminance was almost never a real issue.

Still, we will face some projects soon, in which the feature of having light-selects might again come in handy again.

Are there any plannings to implement this feature into Corona in the near future?
I would also like to know how you other guys handle this or if there is a work-around.

8

[Max] I need help! / IES in reflections and IDs behind glass

« on: 2015-12-09, 09:50:46 »

Hi Corona-friends,

I have come across some minor issues when doing the first official project with Corona.
So far it went really great and I had to do much less post-production, but there were two things that bothered me and I could not find a solution.

1:
When I render the WireColor to get my selections for PhotoShop, things that are behind glass do not work properly. They just get the color of the glass's Wirecolor. In the example there is a kitchen-situation behind the glass of the door and all the stuff behind the door just got the color of the glass-ID. Is there any fix for this? In Vray it was related to material-parameters in which I would have to make sure that the transparency also affects the ID-channel, but I could not find any option like this in Corona.

2:

When working with IES-files in Corona-lights I noticed that despite having the IES-file for light-distribution, the light still has a shape of its own. So you have the IES-light and on top of it there is always the shape of a sphere/plane etc. It did not bother me that much, except when it comes to reflections because you could always see the shape in it. Attached there is an example in which there is a bright round circle on the glass, which is the reflection of the light source. I could not find any way to turn the shape off, so that I would not have to get red of the shape in post-production.
Is there any way to turn the shape completely off or is this even a bug?

Thanks in advance!

9

[Max] I need help! / [solved]FairSaaS license at home and at work

« on: 2015-12-01, 14:10:29 »

I am not sure where to ask this, so I just take the General Discussion Board.
I have a simple question:

My company bought a FairSaaS in order to test Corona with all its features. So far we are very imperessed and will propably switch to Corona altogether at the beginning of 2016.
I would also like to use Corona at home when I am doing free projects, as I do not want to switch between Corona and Vray.
Is it possible to use the same license at home, e.g. when the workstation at work is turned off?

10

[Max] I need help! / Rendernode with long "Computing secondary GI"

« on: 2015-11-17, 13:35:25 »

Hey there,

I just started using Corona and so far I am very impressed.
Everything is much more streamlined than in Vray and even the rendering of large scenes starts in the fraction of the time that Vray used to start.
But here is also my problem.
I am currently rendering a A3-file with several render-elements via backburner on one of our rendernodes.
On the rendernode I excluded 3dsmax from FTH and I also increased the Virtual RAM to 40GB.
With these modifications I managed to avoid the "system is running low on RAM"-error and the scene seems to precompute much faster.
When the scene starts to compute the secondary GI it takes a reeeeeeally long time. Currently 32 minutes have elapsed and I do not even see any progress on the progress-bar.
On my local machine the secondary GI takes around 5 minutes and the scene will start to render.

Is there anything I can do to speed up the rendering on the rendernode? I searched the forum but could not find any matching solutions.

Specs of rendernode:

OS: Win 7 Ultimate
Processor: Intel Xeon x5680 @ 3,33 Ghz (24CPUs)
RAM: 12GB

Specs local workstation:

OS: Win 7 Prof
Processor: Intel Xeon E5-1650 v2 @ 3,50Ghz (12 CPUs)
RAM: 16 GB