The Dark Side of Corona Bump | 3ds Max

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Yo guys, today I'll be diving deeper into Corona Bump mechanics, because there are a few things that can cause headaches! Luckily ‪@RenderRam‬ has a solution!

[@joonior1985]

There is an option to disable texture filtering globally, for all textures/maps. You must turn on Development/Experimental Stuff rollout (in System tab > System Settings). In the new rollout that pops in Performance tab You must find Basic Configuration group and set Texmap Filtering from "All but opacity" to "None".

[@RenderRam]

Usefull info! ❤

[@tradstown]

Thank you for information! Interesting, why Corona Devs did it, what for... I think they have to make a video explanation of this "jokes"

[@RenderRam]

@@tradstown after this video got released, there's a heated topic on corona forum called "Corona Bump is so broken", you have dev's side of the story there also

[@tradstown]

@@RenderRam thank you! Also, Displacement i broken as well. I wrote devs, they even try to do some with their displacement and after they inform me, that they can't fix it... maybe it will be good next video idea for your channel 😉 I can give you some information about bugs of displacement. Maybe video on KZbin make them move wit these bugs to fix them finally...

[@RenderRam]

@@tradstown sure i'd love to check it! send it to [e-mail]

[@delicfilip5822]

Corona investigator hehe good catch my friend

[@ThomasMiller3D]

Interesting. I ran into an image filtering-related issue with V-Ray once. It was a large scene of an industrial site with very specific landscape. The foliage of some of the plants looked as they should up close, but completely disappeared when far away. I even tested it using IPR and the foliage would slowly disappear the further away the camera was. Lowering the filtering of the opacity map of foliage got rid of the problem. It's good to know that image filtering is an issue, as that might be one of the things I'll check when troubleshooting shading problems. Thanks for sharing!

[@RenderRam]

I haven’t tested, but I’ve heard vray reacts the same way

[@josemarf.junior8752]

Wow! I had no idea about this in corona! I've seen a video where you give this super tip of using the bump to get more spread out and beautiful reflections and I couldn't make it work in corona like I did in FS. In the studio where I'm working they use corona, and I've always noticed a lot of difference between what I see in the interactive and in the final render, maybe it could have something to do with that filter, because in Fstorm I don't feel that difference.

[@RenderRam]

Well, now you can get it to work like in FStorm, that thing was bugging me A LOT, It is still possible to do it in Corona tho, but you constantly need to check your final resolution zoom to get things to look right

[@elzacg]

Super i jako korisno👏👏 Samo nastavi👍

[@jackob7]

Thank you.

[@ynadle1111]

youre the best. thank you for explaining this!

[@adamgr1984]

Lets hope someone from Corona team will see this material too.

[@poison4u]

Thanks A ton!

[@Lupaz77]

Did you try a different noise map and also plugin it into a corona bump converter?

[@RenderRam]

Tried with corona bump converter, no luck This happends with height map, normal map, procedural maps

[@WaspMedia3D]

Awesome tip!

[@E_Clip]

I've never had this problem before and I almost never lower the blur and leave it at 1.0 except in rare cases when I want more sharpness out of a particular map (usually rough/gloss). Your wall shader didn't produce that mirroring effect (but then again you were not showing it at a glancing angle so dunno if its actually there but not visible due to rendering it head on), the black splotches could be from a map that has too much contrast in the small details perhaps? Your black desk puzzled me though. Could it be that your black desk shader didn't have rough/gloss map? I've tried to replicate your result and I get the same mirroring effect when I zoom out only when my shader has 1.0 gloss or 0.0 roughness. Once I introduce some specularity that mirroring effect goes away and I dont have to change the filtering of the bump map.

[@RenderRam]

Hi thanks for the constructive feedback! So the thing is that bump is causing this issue no matter what at all times, bump is constantly shifting, no matter if you use glossy to cover it up or any other feature, if you dominate your blurriness of material mostly with glossy, you won't notice the bump thing that much, but again, bump will still produce a shifting result. As tested with other engines in the video, they don't react like that, that's where my confusion started, because if I have a rough/blurry material, I'll try to push blurriness/roughness mostly with bump, and then add glossy to fill in the gaps, you can check my Glossy vs Bump workflow video here: kzbin.info/www/bejne/jWW6Z5uIeN2Ibdk Because in reality, rough materials start from little bumpy details which I try to physically make with bump, and then deal with microbumps trough glossy map. I find that to produce the most realistic and accurate results

[@E_Clip]

@@RenderRam Oh I see, well thats a different thing then. I've used the same method too, but on rare occasions for metallic surfaces and usually for closeups so maybe that's why I haven't noticed it. In any case, great catch! I tried to see if this happens only on greyscale bump maps, so I did it with a normal map, but the mirroring effect is still there with blur 1.0. Lowering it to 0.01 disperses the reflections just like on the greyscale maps, however it does look a bit different especially when blur is 0.01. I will link the results in a new post under this, if you dont see it, youtube deletes it because of the links. Then I did another experiment with the Corona Physical (the previous tests were on the Legacy shader), but the result was the same as the legacy shader. Basically, I tried to rule out all the variables I could think of, but the result is always the same. Then I tried with different blur values and I dont notice too much difference between the lowest value of 0.01 and 0.1 in terms of quality, but it didnt have any effect on the render times either, in fact 0.01 rendered a bit faster So I guess it doesnt really matter if you drop it down to the lowest value.

[@johnny5132]

thanks for this -great to know. Always wondered why things looked blurred out!!! I was thnking of learning Fstorm - how does it hold up in large exterior scenes? i realise for interiors it does well but large, ram and texture heavy exteriors, can it handle it well?

[@RenderRam]

Depending on amount of memory that you have, it handles instances and textures well. Don’t think you should have any issues if you have about 16gb of memory. If I remember correctly, fstorm’s geometry record is about 350mil unique poly - not instances - unique polys, and it took only 16gb of ram Try it, you can download it, and without paying you’ll have watermark, it has a great scene converter

[@johnny5132]

@@RenderRam thx for the response. I'll have to try and find the time. Do you have a preference over which engine you use for interiors v exteriors?

[@RenderRam]

@@johnny5132 my “native” engine is FStorm, there I feel like home, just because I’ve been working in it since the beginning. When it comes to results, appart from this little bump thing, I feel comfortable in both and can’t really say which is better

[@mayankprajapati7350]

i don't understand to keep bump blur 1 or to keep 0.1

[@Ricardo-de9ju]

What would be the render time cost for that? Honestly, Corona is amazing when we are talking about quality and precision, but render times is becoming a real problem when we watch render engines using GPU, the difference in time is ridiculous. Honestly, I have many doubts regarding the future of this software.

[@fadisoueidi4127]

hmm very intresting. this happened to me in one of my renders where the wall would show such blotches it was driving me insane. I hope this will fix it. thank u very much. cheers. by the way very nice chanel all your vids are short and straight to the point.

[@IllGib]

It have the same issue for baking textures, but seems impossible to solve somehow. I "bumped" my head against for days, it simply blur the bake relative to the distance from the camera, but i don't know if it's been fixed alredy. I messed a bit when i tried to get a full light baked diffuse to feed some models in Unreal, and they ended all horribly blurred, like super small images scaled up. For blur i usaually go 0,25 where i need the details, i read that 0,001 it's kind of overkill and really not reccomended.

[@RenderRam]

I believe everyone has a sweetspot for this, all depends on the needs, that’s why I suggested not to put it everywhere, and it is good to experiment to balance speed vs quality

[@ivanvtorov4432]

Hmmm-kinda weird behaviour/was it all time along you were using corona even on older releases?i actually never noticed such terrible difference like on the table you ve just shown...

[@RenderRam]

Started using corona on version 7, it was there, Corona for C4D also has that “anomaly” Haven’t tested Corona 9 yet, but haven’t seen anything about filtering in update notes

[@hamidsalami7022]

Hi. thanks for explaining this! definitely something that corona team should be aware of. is that happens only for bumps or same happens with normal map?!

[@RenderRam]

Hi, I tested all kinds of maps, procedural, height, normal, all have this issue

[@hamidsalami7022]

@@RenderRam ​ Did you find this issue in vray as well?!

[@RenderRam]

@@hamidsalami7022 i haven’t used vray for a long time, so didn’t test it there

[@hamidsalami7022]

@@RenderRam I see. I will test it and let you know if there is the same issue with vray!

[@koberko]

One important question; why use Corona in first place?

[@tradstown]

I realized, that this issue with procedural maps in Corona Renderer in general, not with bump only. You could see the same artifacts (looks like clipping of map during render) with gradient map, when you using it as mask for some reason. My conclusion is set 0.01 blur for all ONLY procedural maps. Other maps you can use as usual (blur from 0.01 to what you need). I think you should update this video and name of the video because this issue not for bump. Thank you for the video!

[@RenderRam]

Hi, thank you for the comment! if you go to 04:13 min in the video, you can see the same effect happening with a bitmap texture plugged into a Corona bump, I encountered this issue with every type of map, procedural, bitmap, normal, all have the same effect unfortunately. About this affecting other map slots apart from bump, I also noticed it in Opacity, but I haven't noticed anything worth mentioning with other map slots (so far). Thank you for support and happy renderings!

[@tradstown]

@@RenderRam Thank you for reply! Now we know more thanks to you! Together we can realize many things in CG. Have a nice renders as well!