View Full Version : MR+Shave and a Haircut -> Rendering Fur with Hair primitives

09 September 2009, 03:23 PM
Hi everyone,

I've been reading this forum for quite a while and it's only here it seems people respond to shave and a haircut.

Using Maya 2009, Shave and a haircut's Mental Ray hair primitives:

I have 2 issues that I've been trying to sort out:

1) Self-Shadowing and Geometry shadow seems to have no effect when I'm using Hair Primitives.

Here are the settings I'm using:
I have 3 spotlights illuminating Fur. I added Key Light to shave->shadow attributes->Add to selected lights. So the shadow reads fine on the background plane.

On my spotlight I have:
- Depth Map Shadows turned on
- In MR shadow map - detailed Shadow Map
- resolution 512
- samples 40
- softness 0.04

in Render Globals:
- Scanline
- No Final gather or Raytracing

And it all seems to work fine, however attributes in Shave such as self-shadow and geo-shadow don't work anymore which results in a quite a flat image. When I turn to Buffer mode, it seems to work fine though.

Does anyone know solution to this problem?

2) I am trying to sort out a render pass system.
This is easy in Buffer Mode - but unsuported in mental ray hair primitives.

I need to:
output the character mesh + output the hair with a hold out of the character.
As this is hair/fur (a LOT of hair/fur)I am trying to avoid a Render Layer (ie: render everything twice) scenario.
I notice 2 undocumented shaders that look suspicious...and can't find the info anywhere, even the shave site:

Can any one help here ?

Thank you so much!

10 October 2009, 11:20 PM

did you tryed to set in MRAY globals to use RASTERIZER instead of Mental ray or scanline

10 October 2009, 06:35 AM
use resterizer as vmarines said. its alot faster.

PS: puppet shader hairTK + resterizer + detail shadowmap,
cut down a 5min per frame render to 1min for me.

10 October 2009, 02:17 PM
On my spotlight I have:
- Depth Map Shadows turned on
- In MR shadow map - detailed Shadow Map
- resolution 512
- samples 40
- softness 0.04

try this tetsing, create ur hair node on a surface (sphere), Create a light but use 2048 or 4096 resolution depth map, softness .001

now try another one but no softness (.000)

set the shadows to details shadows on the lights or in the mental ray render in quality tab

set the camera very close to the surface do a render

remember set to RASTERIZER (no SCANLINE neither RAYTRACE) this will have huge render times)

hope this can guide you

12 December 2009, 02:13 AM
Did you end up working out a solution to your pass rendering? Id be interested to know what you decided on?

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12 December 2009, 02:13 AM
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