Author Topic: Corona hair bunches hair around guides  (Read 1670 times)

2020-03-05, 13:46:07

JPeters

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Hi There,

Last week I started on a project using corona hair driven by various texture maps for density/length/kink/fizz etc. and I'm running into an annoying issue.
If you look at the image you can see that it creates clusters of hairs for some reason near the guides, rather than spreading the hairs out "evenly".

Corona 5 hotfix 2
Cinema4D R21
Distribution = Polygon Area
Cloning = Off
Density is controlled by a greyscale texture from MARI (linear) and levels are 8.

I've fiddled with pretty much all settings but none seem to want to spread out the hairs more evenly.

Also I did try the "minimum spacing" but this just reduces the number of hairs in a cluster while vastly increasing the render times so it's no option really.

Anyone got experience with this?
« Last Edit: 2020-03-06, 09:54:45 by JPeters »

2020-03-13, 16:09:12
Reply #1

Beanzvision

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Hi, I'm not able to reproduce that here, does changing the distribution to something like "polygon center" have any effect? Are you able to share the scene via our private uploader?
https://corona-renderer.com/upload
Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us

2022-01-17, 23:40:01
Reply #2

jojorender

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If you look at the image you can see that it creates clusters of hairs for some reason near the guides, rather than spreading the hairs out "evenly".
Hi JPeters,
I'm running into the exact same issue. Spend a lot of time playing around with settings to no avail.
Did you find a solution for this?
I want to add a cat with short fur to a scene, but poor kitty looks like a cancer patient.

@ corona team
Does corona hair render clones? Hair object> Hairs> Cloning. I see no difference, only render time goes up.

2022-01-18, 12:16:52
Reply #3

Beanzvision

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@ corona team
Does corona hair render clones? Hair object> Hairs> Cloning. I see no difference, only render time goes up.

It sure does!

Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us

2022-01-18, 15:17:29
Reply #4

jojorender

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Thanks Beanz,
I should have made a simplified setup for testing like you did. I guess on the cat, clones and actual hairs bunch up so much that I couldn’t see the clones.
Any ideas how to distribute hair more evenly between guides? Polys are tris, UV mapped, tried with/ without density map.
The cat looks like a toy. When I make the hair thinner for more realism, I see the skin, adding more hair/ clones doesn’t help, just clumps more.

Will send you the cat model when I get to it. Maybe you can have a look?
Thanks!

2022-01-18, 17:27:58
Reply #5

Beanzvision

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It's getting there, I'm sure we can make it look a lot better. Please feel free to send us the file via support@corona-renderer.com and you can also mention me in the ticket. Thanks in advance :)
Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us

2022-01-24, 07:19:37
Reply #6

jojorender

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Hi beanz,
finally uploaded the file 1643004080_CAT-CORONA-HAIR.zip.
Lowering the softness (seems counterintuitive) helped a bit, but still needs help.
The cat has 150000 hairs x 6 (clones) = 900k . That’s a lot of hairs, but maybe not for a cat?
When you get a chance, please take a look and let me know what can be done to distribute the hairs more evenly.
Thanks!

Added screenshots of the hair settings I used for this image. See beanzvision adjustments and result below.
« Last Edit: 2022-01-25, 18:16:01 by jojorender »

2022-01-24, 14:01:27
Reply #7

Beanzvision

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Thanks for uploading. I will check it out as soon as I can.
Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us

2022-01-24, 15:50:25
Reply #8

Cinemike

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The cat has 150000 hairs x 6 (clones) = 900k . That’s a lot of hairs, but maybe not for a cat?

... that the average cat is sprouting around 40 million hairs—give or take a few million depending on the breed ... (Google)
Which is a sign that cats don't give a sh*t about the poor guys that need to render them as 3D representations.

2022-01-25, 01:14:45
Reply #9

jojorender

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Which is a sign that cats don't give a sh*t about the poor guys that need to render them as 3D representations.
lol ...these selfish bastards!

2022-01-25, 12:48:58
Reply #10

Beanzvision

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Hi Jojo,

I've had a look at your scene and these are my updates.
- Increased hair count from 150000 to 200000.
- Lowered hair segments from 12 to 6.
- Lowered hair guide segments from 10 to 5.
- Changed the root to ''polygon area''.
- Decreased clones to 3 and changed root to .01cm
- Hair thickness changed root to .01cm and tip to .01cm.

Personally, I feel it looks much better and should at the very least, survive the winter ahead ;)



I hope that helps.
Bengamin Jerrems l chaos-corona.com
Chaos Corona Support Representative l contact us

2022-01-25, 18:20:55
Reply #11

jojorender

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Hi Beans, thanks for your feedback.
You are right, makes no sense to have these many segments on short hair like this.
So, effectively you lowered the hair count to 600K, but still looks fuller.
I’ll check out the different “root” options further.
I noticed the battle scar with missing hairs. In that position is no guide. Checking guide distributions and using ‘add guide” tool before grooming (yeah, these lazy 3d cats don’t even groom themselves) seems pretty important for final look.
I added screenshots of the hair settings to my earlier post, might help somebody else…