Chaos Corona Forum
Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: jojorender on 2024-07-03, 13:56:31
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Hi all,
Is it just me or are many COSMOS materials still wrong? It’s mostly random IOR values, or (Maxtree’s) leaves with self illumination ticked on, etc.
I can never use assets out of the box, always have to check everything.
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IMHO A big part of Cosmos Material requires careful attention from who upload it into the library. I don't know if there someone who care the Quality Control. There many trees with IOR set to value 2 or similar.
I know that the library must be useful for Corona and Vray but there a lot of work to do into the material side...
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https://forum.corona-renderer.com/index.php?topic=42843.0
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Hello everyone,
Thanks for reporting things like this.
I'll forward this to a dedicated team so that they can further investigate this and improve the overall workflow.
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Hello @jojorender
Could you please try the following:
-Make sure your Cosmos Browser is up-to-date
-Try one more time importing the asset and see if the issue persists
Note: If there's a pending update for the material, please make sure to update it before importing it into your scene.
Additionally, you can try deleting the downloaded asset first, then downloading it again and importing it to your scene.
Please let me know if the issue persists.
Cheers!
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Your screenshot shows the same issue.
Why is the IOR value 1.0? This is obviously wrong.
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I checked other “new assets” (sorted by date) and their materials are also a mess.
Why does a tree trunk have the same IOR as air? Leaves with self illumination?
Given that we're paying for a subscription to access these assets, we expect them to be of high quality and free from such errors.
What steps are you taking to ensure that future assets are accurate and reliable?
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+1
I guess many are automatically converted from V-ray. But its pretty shoddy IMHO. It wouldn't take that long to check them properly for the Corona versions.
Many less experienced users will leave them as default. Or even use them as 'official' examples of how they should build their own materials. Both are poor outcomes.
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Hi all,
Is it just me or are many COSMOS materials still wrong? It’s mostly random IOR values, or (Maxtree’s) leaves with self illumination ticked on, etc.
I can never use assets out of the box, always have to check everything.
Many Chaos Cosmos assets (especially old evermotion) are simply outdated and have old shader setups: completely strange IOR values, no reflections, oversaturated, ultra-bright, or ultra-dark textures, etc. Just my opinion. You can check this by opening them using vray.
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I noticed that exports from Vectorworks to C4D also have very low IOR values when I convert these VW/Cinema materials. I need to manually change those. Maybe something in the Corona convertor is mixed up.
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Agree, i have the same experience. Outdated assets and wrong values.
Also the colors in viewport and material previews are incorrect.
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Please can you give specific names of models that are importing incorrectly, so that we can look into those - you don't have to list every example that you've seen a problem with, but one or two would be useful. As a note, Cosmos stores materials in its own unique format, so we need the examples to see if this is a problem in writing the Cosmos materials, or a problem with Corona reading from those Cosmos materials and creating the Corona settings. We don't want to second-guess which ones you are having problems with, so having the names of those in Cosmos will make sure we are on the right track! Thanks!
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For example these two. Look at the incorrect r-values. Often the glossiness is off as well at 100% without a map.
The usual manual corrections I have to do are incorrect glossiness, incorrect r-value and too saturated colours in case of people. These I correct with a gamma adjustment of 1.2. I have a feeling that the convertor is faulty. The CR scene convertor produces very low r-values I noticed.
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Thanks for the examples! I'm taking a look into it :)
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And I've taken a look, into the examples given which were the Mountain Alder 005 model (focusing on its Bark material) and the material on the 1964 Bill Standing model. The imports into Corona are correct based on the original source of the materials. If you import into V-Ray you may see a higher IOR, BUT V-Ray also uses a Reflection intensity value (a color) and any such Reflection value lowers the IOR in Corona because we do not have a Reflection value (we're more physically correct ;) ).
So, Bill is IOR 1.6 in V-Ray (the Reflection IOR is locked to the Refraction IOR, so the 1.6 value can be found in the Refraction IOR in the V-Ray Mat, even though refraction is not used), BUT it has a Reflection of black; that is, zero. The equivalent in Corona of "no reflection at all" is IOR of 1, which is how it imports.
The tree bark has an IOR of 1.52, but a Reflection of RGB 96, 96, 96, which is quite a dark grey and so lowers the reflection significantly. The IOR when loaded from Corona is 1.06, which reflects (pun intended) the low reflectivity that the material is meant to have.
Both materials render and look "okay" in Corona (and in V-Ray) - they are not the most fantastically detailed, accurate and realistic materials, but that is not a flaw in the conversion either when moving the model onto Cosmos nor when loading it into V-Ray or Corona; it is simply how the original materials are - fairly straightforward and basic. You may want to adjust them to give a look that you want, but on import those are not unusable or broken in any way.
Hope this helps!
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Thanks Tom,
I noticed though that these materials with very low IOR's look like crap. Weird is that some assets are converted with these low IOR's and others not. I had never seen any help manuals or references on how to work with Coronamaterials where the practise is to lower IOR values to 1 or less to obtain realistic results for 3D people, trees and so on.
I have most Maxtree corona assets and I have never seen any with these low IOR's other than those from Chaos Cosmos. Apparently Chaos does not use the Corona set up provided by Maxtree but converts the Vray ones. When I export Vectorworks files to C4D I notice that IOR's values are wrongly converted from C4D standard to Corona PB with IOr's 1 or less. The converter is broken for IOR values and reflectivity. Many of the Chaos 3D people assets are glossy like glass statues and do not look "okay" at all.
I use Cosmos as little as possible and only to convert assets in to the C4D asset browser to make sure I don't get a project rendered out with unexpected results.
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I too think there should be a fundamental look at how the corona assets are being created for the COSMOS asset browser. They often feel like automatic conversions without the level of care and oversight that I'd like.
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This is what the people look like straight from Cosmos.
The third from the left is Alexei and has a texture, roughness and bump map and a IOR of 1.54 and looks okay.
The zombies are:
Janna has maps for texture, glossiness, edge color and bump and a IOR of 2 and looks unrealistically bright.
Zeef has to live with just a texture map and looks unrealistically oversaturated.
Kaden has a texture, roughness and bump map and an IOR of 1.054 and looks unrealistically dark.
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Do note that there are no "Corona assets" in the Cosmos browser - they are universal assets, created once, then used everywhere. Unfortunately they are not all as physically correct in their set up as Corona materials are, as noted earlier some have a "reflection color" which is used to dampen the result which can only be calculated in Corona as a change to the IOR as we (correctly) don't have the concept of reflection color. The material conversion done to get things in to Corona is also universal, and not asset specific, so we have to apply the same rules to every object in translating its materials into Corona.
The only possibility I can think of there would be to have the original materials edited to not use something like reflection color and just use IOR, making the materials more physically correct, and done in such a way that when we read them they would arrive in a better state - and that would be a request to be sent in via ticket to the Cosmos team, as it involves changing the models at source. Thanks!
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Thanks Tom for your kind replies.
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Thanks for taking the time to reply Tom. I understand that they are Chaos and not 'corona' assets. But as they are the only material and asset library that ships with Corona since the native library was discontinued - I really feel that they should be adapted for use in Corona properly.
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I wouldn't disagree, I do think it would be worth a ticket (from users, to emphasize the importance of this) to request the source materials be reworked to be more readily compatible with all render engines. You can explain the problem being the use of Reflectance Color to "dampen" reflection strength without modifying the IOR, where Corona has to modify the base IOR as we (physically correctly) don't have reflection color - so if source materials were modified to simply use IOR with reflection color white, they should translate better. Perhaps better yet it can be a feature suggestion on the Cosmos board, as then it can be suggested once and then voted for :) https://chaoscosmos.ideas.aha.io/ for the portal, and if anyone does post a request, you can let us know here as then those interested can vote for it.
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I've added a 'idea' to the portal.
After downloading a coloured glass material form cosmos the other day I noticed that volumetrics weren't even turned on, so it was actually colourless. Such a simple problem that should be picked up by quality control.