View Full Version : Optimize Causes Black Renders

02 February 2006, 07:45 AM
alright, i'm working on an eye in maya 7, finished it up and everything, i'm happy with the results, and like i usually do at the end of a phase, i'm going through cleaning up all the junk that isn't necessary. i ran "optimize scene size" with everything selected (it's a very simple scene), because that was pretty much the easiest way to do most of it. the problem is, when it was done, the front of the cornea renders black, rather than transparent. the reflections still seem to show up, it's just no longer transparent, and it has changed color.

i restored to a previous save, and went through each option in the optimize scene size, and figured out it is the "delete unused render nodes" option, which is the same as the "delete unused nodes" in the hypershade.

now the easy thing would be to just go from the earlier save, and just not use that option. however, that's no way to learn. somewhere down the line, something like this is going to come up, and if i know why this is happening, i can avoid it and/or fix it.

using maya 7
rendering in mental ray, it comes up black, renders fine in maya software
doesn't seem to change any settings on the shader
only affects that one shader
the affected shader has transparency, reflection, and refraction, with ramps mapped to the first two to simulate the fresnel effect.
not using any 'bad' files in mental ray, just regular rgb/8 tiff files

02 February 2006, 09:11 PM

it's so hard to find good help these days.

02 February 2006, 10:54 PM
Delete unused nodes command will delete all nodes not connected to any shader network or all nodes which are connected wrong, so Maya dont understand can happen if you have some MR nodes which you forgot to connect to SG or connected the wrong attributes on them....Sometimes it happens to me when i have a single shader connected to a pair of SG groups...Also its a good habbit of mine to not to delete all unused unitility nodes manually onу by one, searching for them in different tabs but to wash out all of them at once with "Deletу Unused Nodes" command...As long as you know that all your nodes are connected properly you dont risk to loose them since they will not be affected by this command....

Hope it helps a bit

Hmm and about your black render in Mental Ray some more info on your you use Maya shaders or MR ones?

03 March 2006, 04:53 PM
edit: so much for that.

03 March 2006, 05:49 PM
alright, got a little update here. i basically have two shaders: the eyeball cornea, and the iris. the first shader is the one that goes wonky, and i can't figure out what it's deleting/changing.

i'm using the maya shaders, rather than the mental ray ones.

my network (i don't know where to look for that spiffy little plugin that gets a screengrab of your hypershade network)

bump 2D
low level noise
eyeball bump file
color ramp
color inputs
file input
transparency ramp
color input (1)
falloff ramp input
surface sampler info-facing ratio input
reflectivity ramp
falloff ramp
surface sampler info-facing ratio input

if someone knows what that plugin is called that records all your shader network connections, let me know and i'll use that to post a more detailed description. in the mean time, if you PM me, i'll send you the shader network (minus the images, sorry, i'm not that nice)

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03 March 2006, 05:49 PM
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