Tag Archives: Yeti

The case of the missing Yeti fur

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In this case, a client complained that Arnold wasn’t rendering Yeti fur. I asked him to try with a simple sphere, and to send me the log (at verbosity level Warnings + Info).

This what I was looking for:

00:00:00  1222MB         | there are 1 light and 2 objects:
00:00:00  1222MB         |       1 persp_camera
00:00:00  1222MB         |       1 skydome_light
00:00:00  1222MB         |       1 utility
00:00:00  1222MB         |       1 lambert
00:00:00  1222MB         |       1 driver_exr
00:00:00  1222MB         |       1 gaussian_filter
00:00:00  1222MB         |       1 polymesh
00:00:00  1222MB         |       1 list_aggregate
00:00:00  1222MB         |       1 MayaShadingEngine
00:00:00  1222MB         |       1 renderview_display

So, what’s there? Well, the important thing is not what’s there, but what’s not there.

There’s no procedural. If Yeti was installed properly, there would a procedural node. The Yeti extension exports a procedural node when MtoA translates the scene.

That means the PATH or MTOA_EXTENSIONS_PATH wasn’t set up properly. I always use the Yeti module file for that.

[MtoA] Mapping textures to Yeti hair

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Like MtoA, Yeti exports UV coordinates in the uparamcoord and vparamcoord parameters, and you use these to map textures in the aiHair shader with the Uparam and Vparam extra attributes.
yet_uv_3

For example, if you plug a texture into the Rootcolor and tipcolor
yet_uv_2
then you can use uparamcoord and vparamcoord to map that texture onto the hair:
yet_uv_1

Tip If you enable Expand Procedurals and export an ASS file, you can see what parametes Yeti exports:

### created by pgYetiMayaShape
curves
{
 name pgYetiMayaShape_|pgYetiMaya|pgYetiMayaShape|scatter01_pSphereShape1_grow01
 num_points 621 1 b85UINT
# ...
 points 4347 1 b85POINT
# ...
 basis "catmull-rom"
 mode "ribbon"
 min_pixel_width 0
 visibility 255
 self_shadows on
 matrix
 1 0 0 0
 0 1 0 0
 0 0 1 0
 0 0 0 1
 shader "initialShadingGroup"
 opaque on
 id -1230660816
 declare curve_id uniform UINT
 curve_id 621 1 b85UINT
# ...
 declare uparamcoord uniform FLOAT
 uparamcoord 621 1 b85FLOAT
# ...
 declare vparamcoord uniform FLOAT
 vparamcoord 621 1 b85FLOAT
# ...
 declare surf_s uniform FLOAT
 surf_s 621 1 b85FLOAT
# ...
 declare surf_t uniform FLOAT
 surf_t 621 1 b85FLOAT
# ...
 declare length uniform FLOAT
 length 621 1 b85FLOAT
# ...
 declare fur_id uniform FLOAT
 fur_id 621 1 b85FLOAT
# ...
 declare surf_n uniform VECTOR
 surf_n 621 1 b85VECTOR
# ...
 declare filename constant STRING
 filename "C:/Users/StephenBlair/Documents/maya/projects/Support//yeti/tmp/yeti_combExample_pgYetiMayaShape_1886244453_1.fur"
 declare mtoa_shading_groups constant ARRAY NODE
 mtoa_shading_groups "initialShadingGroup"
 declare frame constant INT
 frame 1
 declare verbosity constant INT
 verbosity 1
 declare density constant FLOAT
 density 10
 declare width constant FLOAT
 width 1
 declare threads constant INT
 threads 0
 declare min_pixel_width constant FLOAT
 min_pixel_width 0
 declare mode constant INT
 mode 0
 declare imageSearchPath constant STRING
 imageSearchPath ""
 declare samples constant ARRAY FLOAT
 samples 1
}

[MtoA] The case of the scene that crashed Maya

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In this case, Maya crashed as soon as you loaded a certain scene.

What was the problem? Yeti couldn’t get a license, and then when MtoA loaded the Yeti procedural, that was it: crash.

We found the problem by checking the Maya log that we got with the -log command-line flag:

maya.exe -log %TEMP%\maya.log

The solution was to set RLM_LICENSE so Yeti could get its license (or unset MTOA_EXTENSIONS_PATH so that the Yeti extension wasn’t loaded, or move the Yeti module file so Maya wouldn’t find it).

This is what we saw in the log:

[Wed Nov 05 18:08:13 2014] Yeti 1.3.14: Yeti v1.3.14, built on Oct 10 2014 at 20:52:13
[Wed Nov 05 18:08:13 2014] Yeti 1.3.14: (c) 2010-Present Peregrine Labs a division of Peregrine Visual Storytelling Ltd. All rights reserved.
[Wed Nov 05 18:08:13 2014] Yeti 1.3.14: ERROR pgLicenseCheck - License system could not get a valid server handle, error: Can't read license data (-102)
No such process (errno: 3)
00:00:00 WARNING | [mtoa] Extension pgYetiArnoldMtoa(C:/solidangle/yeti/Yeti-v1.3.14_Maya2014-windows64/plug-ins/pgYetiArnoldMtoa.dll) requires Maya plugin pgYetiMaya, registering will be deferred until plugin is loaded.
the data object was unable to read its value : (0) no error
the data object was unable to read its value : (0) no error

****
* Arnold 4.2.2.0 windows icc-14.0.2 oiio-1.4.14 rlm-11.1.2 2014/11/03 15:27:54
* CRASHED in QResource::locale 
* signal caught: error C0000005 -- access violation
*
* backtrace:
*  0 0x000000002c8b7a20 [ai            ] AiArray                                           
*  1 0x000000002c8b9f80 [ai            ] AiArray                                           
*  2 0x000000007722b940 [kernel32      ] UnhandledExceptionFilter                          
*  3 0x0000000077343398 [ntdll         ] MD5Final                                          
*  4 0x00000000772c85c8 [ntdll         ] _C_specific_handler                               
*  5 0x00000000772d9d2d [ntdll         ] RtlDecodePointer                                  
*  6 0x00000000772c91cf [ntdll         ] RtlUnwindEx                                       
*  7 0x0000000077301248 [ntdll         ] KiUserExceptionDispatcher                         
>> 8 0x0000000067840147 [QtCore4       ] QResource::locale    
...
...and so on and so on...

[MtoA] Pimping your Yeti module file

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Here’s a variation of the Yeti module file that adds the bin folder to the PATH, and plug-ins to MTOA_EXTENSIONS_PATH:

+ pgYetiMaya any C:\solidangle\yeti\Yeti-v1.3.14_Maya2014-windows64
PATH +:= bin
MTOA_EXTENSIONS_PATH +:= plug-ins

MtoA uses MTOA_EXTENSIONS_PATH to find the Yeti extension for MtoA, and Arnold uses PATH to find the Yeti procedural.