Mental Ray contours

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

THREAD CLOSED
 
Thread Tools Search this Thread Display Modes
Old 05 May 2009   #1
Mental Ray contours

Hello CGSociety! (obviously, this is my first post)

I need some assistance with a project I'm currently on and maybe develop a technique to avoid this in future. So, what am I trying to do is displayed in the following image:

You can see that further away the bridge gets completely "contoured" to black. I'm using distance and normal contrasts to detect edges. If I increase the value in distance I can clear out that but then I get a lack of edges in other places, inside the tube, for example.

I tried to google it but had no luck.
 
Old 05 May 2009   #2
I think it's the distance contrast. Only use the normal contrast, and I think it will be better.
 
Old 06 June 2009   #3
Yes, that would get rid of that nasty black area, but then some of the other contours would be lost. This image fails to illustrate the problem clearly, but if you would look really close inside the bridge you would see structural features that are parallel and do not trigger the normal contrast. It seems that Mental Ray calculates distance in some weird, non-linear way.

Not to worry though -- it is a still image so I can fix one frame . What I am looking for is a permanent solution (custom contrast shader maybe).
 
Old 06 June 2009   #4
That is most likely because your normal contrast attribute, angle, is too large. From what I see that is a quite shallow angle, so your setting needs to be something low for that to register. At least that might be it .
 
Old 06 June 2009   #5
I modeled the segments, I know that the faces are parallel. Normal contrast - won't work here. I think that a UV contrast with some sneaky UVs should work here. This is only a temporary solution, I could need to texture models.
 
Old 06 June 2009   #6
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
__________________
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
 
Thread Closed share thread



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
CGSociety
Society of Digital Artists
www.cgsociety.org

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump
Miscellaneous

All times are GMT. The time now is 12:49 AM.


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.