Hi, i need help! I'm doing some test with houdini fur tools, but when i go to render i take images with a lot of noise.

I tried Micropolygon, Raytraced and PBR with the same results, i have two spot light (a key anf a fill light with 1 and 0.6 intensity) and i'm rendering at 720p. Pixel samples 8x8, but i've tried to change all settings with no results.

I post an image to specify what i mean, the beard is very noisy, an when i compose the animation (a simple turn table) the result is very bad.

Can someone help me?

try using shadow maps and you can use the blur in them to smooth the shadows,
if you are using area lights you can increase the samples,
and you can increase the pixel samples in the mantra node,

depending how thing your hairs are, you might need to increase the pixel samples, some times, you can even increase the with of the hair, and the width will still be smaller than a pixel. so be carefull with that.

I'm using spot light, now i'm tring with shadow maps and with 2 click looks better and takes less rendering times

Do you think that i should use area light? And what render engine do you advice?

Thank you very much!

well, now I have much less noise, but the problem persist during the animation of turn table.

Tips? I've to activate DOP and Motion Blur?

Deep shadow maps 512 x 512 and blur them

Rob

circusmonkey
Deep shadow maps 512 x 512 and blur them

Rob

Thanks Rob for the reply.

I'f i blur the shadow the results is very bad, and render time jump to sky!

With this settings:
Shadow blur 0
Resolution 2048x2048
pixel samples 8x8
depth map motion blur enabled
and others to default

I obtain a good render (last image), the problem is during the turn table animation in wich noise disturbe the quality and i don't know how to reduce it.

I tried to reduce the noise value in render settings from 0.05 to 0.01 with no results.

Any tips?

I'll post the render with 512x512 with blur soon.

Very different result and render time like 6-8 time slower with blur 0.1

with blur 0.01 i obtain a darken render for the face, and a beard similiar than without blur.

Tips?

Do you have transparency on your fur shader? If you have you need to play with transparent samples in the mantra sampling tab.

If you hairs are too thin you are going to need more samples, try to increase your thickness to see if it helps with noise longer thin tips can be a issue.

And for the shadows I prefer to use area lights the results are better and much easier to setup but render time is a little longer but is where I got the best results, there is a technique that can help with that but it needs setup you can take a look here:
http://www.sidefx.com/index.php?option=com_content&task=view&id=2694&Itemid=132 [sidefx.com]

I hope that helps.

Cheers.

I'm already using 8x8 pixel samples, even increasing to 16x16 i have minimal or no improvements.

Which render engine you advice? The posted results are obtained with raytraced engine.

I'm trying to replace spot light with area light, i'll post new render soon.

Use always PBR the new hair model works really well with that, i even used it with enviroment lights, and like I said check the thickness.

Thank you very much for your answers and advice. I set the scene with the area light. The settings are:

Sampling quality: 1 (higher value don't give me better result)
Depth Map shadow
All default and
Blur 0.01
512x512
samples 2x2
and even for these three, higher value doesn't give better results.

Mantra PBR
Tilesize 16
pixel samples 8x8
Min Max rays 1-9
Noise 0.05
Transparent samples 8

Any higher settings doesn't give me tangible changes.

I also increased the thickness of the beard from 0.007-0.015 to 0.015-0.02 with no better results..

luix93

circusmonkey
Deep shadow maps 512 x 512 and blur them

Rob

Thanks Rob for the reply.

I'f i blur the shadow the results is very bad, and render time jump to sky!

With this settings:
Shadow blur 0
Resolution 2048x2048
pixel samples 8x8
depth map motion blur enabled
and others to default

I obtain a good render (last image), the problem is during the turn table animation in wich noise disturbe the quality and i don't know how to reduce it.

I tried to reduce the noise value in render settings from 0.05 to 0.01 with no results.

Any tips?

I'll post the render with 512x512 with blur soon.

Hi, using a 2k shadow map is not correct and the wrong approach. If your going to blur a shadow map you go small, even 256 x 256. and blur. I designed a lighting rig for Fur that reads in a HDR , and then placed instanced lights in dome. each light sampled the HSV values of the HDR
and also located the brightest averaged pixels in the HDR to place a key light.
Check out the panda on my site http://www.circusmonkey.com.au/circusmonkey/Gallery.html [circusmonkey.com.au]

At the time of doing this the fur shader needed re engineering to work with PBR. So do test as PBR is way faster now. Try rendering with a small blurred HDR map in a .rat format. Ray trace bias settings will be important .

Rob

circusmonkey

luix93

circusmonkey
Deep shadow maps 512 x 512 and blur them

Rob

Thanks Rob for the reply.

I'f i blur the shadow the results is very bad, and render time jump to sky!

With this settings:
Shadow blur 0
Resolution 2048x2048
pixel samples 8x8
depth map motion blur enabled
and others to default

I obtain a good render (last image), the problem is during the turn table animation in wich noise disturbe the quality and i don't know how to reduce it.

I tried to reduce the noise value in render settings from 0.05 to 0.01 with no results.

Any tips?

I'll post the render with 512x512 with blur soon.

Hi, using a 2k shadow map is not correct and the wrong approach. If your going to blur a shadow map you go small, even 256 x 256. and blur. I designed a lighting rig for Fur that reads in a HDR , and then placed instanced lights in dome. each light sampled the HSV values of the HDR
and also located the brightest averaged pixels in the HDR to place a key light.
Check out the panda on my site http://www.circusmonkey.com.au/circusmonkey/Gallery.html [circusmonkey.com.au]

At the time of doing this the fur shader needed re engineering to work with PBR. So do test as PBR is way faster now. Try rendering with a small blurred HDR map in a .rat format. Ray trace bias settings will be important .

Rob

I really love your panda!
With blur i'm using 512x512 maps, not 2k, but the noise problem persists.

This is not the only test i'm doing, but in everyone i have that problem, and most of the noise is in the area with more density.