How create a towel(material)

[akkoxe]

I need create a towel. If i use bump, results are not realistic, look pls in attachment.
if i use hair and fur or scatter, my PC say me "good bye" and crash 3ds max. 32gb ram
If i use displasement-results is not good if pixel size or pc crash if world size (i try 0,5 mm)
How you create towels, realistic towels for closeapp? Tnx

[maru]

Is the image your result, or a reference? Because I would say the towels look pretty ok. If not bump, I would recommend hair and fur or scatter. It should not crash. Are you getting any errors before the crash?

[akkoxe]

its my, i want make closeapp, show towel and mirror. But if i bring close towel i have result like it. http://img14.deviantart.net/caae/i/2007/188/a/d/towel_material_by_stoo_stock.jpg (but no small fuzz)
but wand like it http://www.jin-sky.com/assets/images/terry%20fabric%20towels%201.jpg i try do it H&F(like carpet on floor, i do it H&F, but in carpet only 30 poligons). In small area - its working. But all towels - its crashed. because more poligons on towels i think. =)

[Juraj]

Displacement for small details is almost unusable, even if you have the performance it will progressively take, you will be waiting tons of time before the render, for something that doesn't look exactly amazing.

Micro-disp is something that Vray's 2D model (texture-space) model works much better, it doesn't receive correct lighting between details, but it's fast.

Towels are nightmare... best studios still use photography in Photoshop.

I keep towel models "thick" and rounded. And then use heavy bump.

[FrostKiwi]

I recall a Corona Studio struggling with towels aswell and finalizing a model they use now non stop somewhere in the forum. They sell that on turbosquid, might wanna forum search.

Edit:
Ahh found it.
https://forum.corona-renderer.com/index.php/topic,10820.msg69103.html#msg69103

Maybe buy one of their models and look how they did it or politely ask OP.

[Christa Noel]

towel detailing gaves me a headache too but once it solved good points to my scenes, it steals customers attention but very heavy and hateful. like juraj said, displacement is a NO for towels.
hair n fur is the best way to reach the good quality result like those photo reference. or you can try coronascatter.
but if it is crashed 3dsmax, you should report it.

[maru]

Here is my attempt. I baked normal maps of a plane with hair and fur applied. It still doesn't look that great on closeups, but I'm pretty proud of it anyway. :)
In the closeup I enabled some additional displacement to create the effect of uneven edges (simple noise map, 4px displacement size so that RAM does not suffer that much).
Scene: https://www.dropbox.com/s/8sui3nbbrzljukj/towel.zip?dl=0

[FrostKiwi]

It still doesn't look that great on closeups, but I'm pretty proud of it anyway. :)

This is really sexy!
Nobody is going around with a magnifying glass looking at towels anyways, like in the last image ;]

[Christa Noel]

It still doesn't look that great on closeups, but I'm pretty proud of it anyway. :)

This is really sexy!
Nobody is going around with a magnifying glass looking at towels anyways, like in the last image ;]

yes saires, nobody won't do that, but about 2-3 years ago a client asked me to create additional shot that closeup to a granite material of vanity table with many accessories above it including the folded towel.. and my towel didn't look that sexy :D

[PROH]

Hi Maru. Thanks for sharing your towel material. I think this is the best towel material I've ever laid my hands on :) Are we allowed to use it in private or commercial projects?

Another (maybe stupid) question: How did you bake the normal maps - is this done with Corona texture bake or did you use a max-script or external program?

If it's Corona, I think a tut about doing this would be great.

Best regards

[romullus]

@PROH: you don't even need to bake such objects. Just add CGeometry_NormalsShading render element and render elements only from top projection. That's it. Just remember, if you want to use normal map aquired this way in 3ds max, you have to invert green channel first.

@maru: towel looks great. Wonder how it would stand in strong sunlight? Shadow terminator issue could be amplified by much.

[PROH]

Hi Romullus. Thanks for explaining. I'll try this method out - it's much simpler than I thought :)

Thank you.

[selant]

I need create a towel. If i use bump, results are not realistic, look pls in attachment.
if i use hair and fur or scatter, my PC say me "good bye" and crash 3ds max. 32gb ram
If i use displasement-results is not good if pixel size or pc crash if world size (i try 0,5 mm)
How you create towels, realistic towels for closeapp? Tnx

akkoxe its not directly about the subject but i really really like the way you light the scene. can you give some clues about the balanced lighting, how many light sources did you use ?
Especially i like the area below the sink, the wooden cabinet with the towels.. The light seems and reflects so realistic there.. Hope to know much about it.. Thank you!

[maru]

As Romullus said - I just placed camera over a plane and rendered the normals element. I didn't know about the flipping green channel thing, though, so the results might be incorrect (look pretty ok though). :S

I think I attached the scene which was used to bake the maps.

You can use the scene, maps, materials in any way you wish - commercial too.

[maru]

Hmm I just checked with different settings of the normal map and it looks like "flip red" produces the correct result. So the previous ones are bugged, but look... better? :)

yes, the terminator is strong in this one...

update: my scene is probably messed, normally green channel should be flipped

[PROH]

Yes, flipping green channel is definitely NOT giving the best result in this case.

IIRC there was issues with Normal maps prior to max 2014 - but they should have been fixed in v 2014 and newer. So just wondering.. is "invert green channel" an old habit, or does it still count?

[romullus]

In 3ds max, unlike in most other apps, one still has to invert green channel. At least up to max2014, but i doubt it will be ever changed/"fixed". There is probability that Ondra had change how CGeometry_NormalsShading is rendered - i posted such request long time ago, but it was declined. Maybe he changed his mind? :]

[maru]

He changed it so that now you need to flip red channel, he thought you won't notice.

[romullus]

Well, i didn't :] *

* it's just a joke, one still has to invert green channel of normal maps aquired through Corona's RE.

[CASA_MT]

Towels are really still an issue sometimes.
I think for medium distances good textures and sometimes displacement can work very well. We try to avoid having towels in a clos-up and if so, we tend to blur them a little by placing them in a defocused position. This softems the spikey displacment-parts a little. The blue-ish towel in the attachment is an example for this.

I think when it comes to really close camera-positions, there is no other way than to use some sort of scattering.
I tried a quick test with cloth-plane and scatterd towel-fibres with a sliglty transluscent material to get some kind of softness. Of course the towel itself could look nicer, but I just wanted to get a quick idea of how the fibres might look like and I think it does go in the right direction. Maybe this can be an inspirition on how to deal with extrem close-ups.

[Juraj]

Looks good :- ) Wasn't brave to do much scattering lately but this seem like really sound idea.

[cecofuli]

Origial idea =)

https://forum.corona-renderer.com/index.php/topic,1337.msg10011.html#msg10011

[romullus]

Yes, flipping green channel is definitely NOT giving the best result in this case.

IIRC there was issues with Normal maps prior to max 2014 - but they should have been fixed in v 2014 and newer. So just wondering.. is "invert green channel" an old habit, or does it still count?

Out of curiosity did quick test and it clearly shows that "invert green channel" advise is correct. Maybe there's something messed up in maru's scene? Didn't tried to look at it yet.

In attached pictures: left - geometry, right - plane with baked normal map.

[PROH]

I see... very interesting. So Ondra didn't change it after all :)

Since there's so many different opinions/workflows that doesn't fit well together, I think it could be useful with some sort of "how to normal maps the correct way"-tut, that show one consistent workflow for both making and using normal-maps with Corona.

Thanks for following up.

[romullus]

That red channel flipping was just a joke (will add notice to my post to prevent further confusion).

As for normal maps, it's not that complicated. Usually you have to flip green channel if map was baked outside 3ds max (or aquired through Corona's RE). 3ds max's render to texture (RTT) outputs "correct" normal map, i.e. you don't need to flip anything. Didn't check Corona's RTT yet.

[PROH]

I know the "red channel" was a joke. Should maybe have used this ;) instead.

Regarding workflow, then it's more confusing than complicated, since flip/not flip depends on various things. Hope I get some time to dive deaper into this myself.

Thanks

[maru]

Yep, my scene is probably messed. I used shell modifier which could have resulted in flipped normals. If not that, then maybe I flipped normals intentionally for some reason, sorry I don't remember. However if you are creating any similar maps, it should be fairly easy to tell which setting works fine - just place some directional light source close to your object and observe how shading changes.