Hi,
Im getting really weird (reflections?) along the edges of my objects. If you look closely at the coffee mug or the eggs youd see what I mean.Any ideas what might be going wrong?
Unfortunately it looks like this, so this would be expected:
Solution is to change material settings, for example reduce reflectivity.
Could another option be to revert back to the old default BRDF by ticking the 7. 2 legacy checkbox in the advanced rollout, you may get more predictable results.
If you are desperate for GGX without significantly changing material behaviour you could try the nested blend approach as described in this thread:
[https://forum.corona-renderer.com/ GGX - best way to recreate it for all metals, problems translating to Corona ](https://forum.corona-renderer.com/ GGX - best way to recreate it for all metals, problems translating to Corona )
You mean reduce reflectivity level, or the reflection color to a darker value?
It should have the same result.
Is this 1.0 version? Use UHD cache indstead of HD.
Is your problem too much noise or that it takes too much time? I can’t see much noise in this image.
Yea im using 1.0 demo version. Im new to Corona so I wouldnt know what the best balance between quality and time?
Generally, if you have some goal rendering time you would like to achieve, and you get bad results in it (for some reaseon), you can:
-ignore noise for now and see how many passes produce good edges of geometry and textures (or example if it’s 16 passes, or 32, or 64?)
-then use the lowest possible number of passes (let’s say 16)
-render 16 passes and see if there are any other problems (noise?)
-if there is noise, this most likely means you need to increase sampling settings, either GI/AA value or LSM
This is just an example. If you don’t care so much about rendering time, you can simply set no time/pass limit and just wait for the image to refine.
Maybe this guides will be helpful:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516729
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516731
Something is wrong with your image, there’s almost no contact shadow. Check your material settings and or HDRI quality.
Render settings are also wrong. If i’m right, there’s no enclosed enviroment in your scene. In that case you don’t need such high GI samples. Set GI vs. AA to 8 and LSM to 4.
Your liquids are modeled incorrectly. Look here how to properly do this in Corona: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515618-how-to-model-a-liquid-in-glass-in-corona-
Also you’re getting too lowperformance out of your CPU. Might be due to bitmap paging. Read this: Warning!!! Disable bitmap paging! - Corona for 3ds Max :: General - Chaos Forum
Thanks a bunch man very informative. However, what is there to be checked in my materials tho? what might be preventing the contact shadows?
Thanks for the links. Tho, do you have any idea why im not getting contact shadows out of my materials?
Hey guys, heres a quick update, I remodeled the liquid based on the link that romullus provided but the milk renders kind of odd looking as if its outside of the glass.
P.S: I rendered the scene with a different HDRI which is quite high res (200mb in size) but still im not getting any contact shadows! 
This is correct. See http://upload.wikimedia.org/wikipedia/commons/9/9d/Presidents_Choice_-The_Decadent,_chocolate_chip_cookie,_with_a_glass_of_milk.jpg Your glass is very thick, that’s why it’s even more apparent.
Contact shadows - I think it’s more dependent on light than on materials unless your are using an incorrectly set up bump map.
well as far as light goes, im using an HDRI in the environment slot, thats pretty much it. Is there anything to do to get decent contact shadows without doing it in post?
Hi. Try this:
-
Check how HDRI behøves with default corona materiale. Make a small box on top of a bigger box, both with default material. Are there any contact shadows? If not, you need more light. If yes, then go to next point.
-
How is the table material made? Shadow catcher or a Wood-material? How does it behave without bump/normal map/displacement? Any kind of self illumination?
Hope it helps
There is shadow. But if you want it to be more distinct, make sure that yor object don’t touch ground very firmly. Either lift them a notch, or give a small chamfer to outer edges of those boxes.
File size of HDRI tells almost nothing about its quality.
So how do I tell if an HDRI is high quality or not? Any personal favorite website you may wanna suggest where I can get decent HDRI ?
This will get you going:-
Perhaps when setting up lighting / playing with HDRIs, start with all objects using the same simple Corona material.
This will help you understand light and shadow interactions better.