Beer glass scene creation
This course contains a little bit of everything with modeling, UVing, texturing and dynamics in Maya, as well as compositing multilayered EXR's in Photoshop.
# 61 16-03-2008 , 07:32 PM
DJbLAZER's Avatar
Registered User
Join Date: Jun 2004
Location: Gothenburg, Sweden
Posts: 1,318
I just read through quickly about your problems...

Are you rendering with a displacement? Or a normal map as bump? What color space is the image in - 8 or 16 bit? That contour you're getting in the render is a typical problem when rendering displacements with an image with too few colors.

# 62 16-03-2008 , 07:45 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
hey - thanks DJbLAZER - i'm rendering with a normal map as bump.

I'm not sure what color space the image is in - how would i check that and change it if necessary?

# 63 16-03-2008 , 08:00 PM
DJbLAZER's Avatar
Registered User
Join Date: Jun 2004
Location: Gothenburg, Sweden
Posts: 1,318
Don't know in ZBrush since I have'nt used it much, but open the file in Photoshop and check Image/Mode in the menu and see if it's 8,16 or 32.

# 64 16-03-2008 , 08:33 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
thanks mate - i had a look in ps and it was set to 8 bit, so tried 16 bit, but i'm still getting the same results...user added image

# 65 16-03-2008 , 08:53 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
i've noticed that when i set my display to high quality, then my normal map looks fine in the viewport - it's only when i try to render with mental ray or software render that it looks crap.

whaaah - what am i doing wrong??user added image

# 66 16-03-2008 , 11:07 PM
NeoStrider's Avatar
Registered User
Join Date: Jun 2004
Location: Cleveland, Ohio (USA)
Posts: 1,541
honestly arran i think the effect kinda works for the jacket, it makes it look like it's made of wet plaster... or something similar, which could work for the texture of a ghost's overcoat...


Accept no substitutions.
# 67 16-03-2008 , 11:16 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
and if i knew what i was doing i met let it be...user added image

but i really need to solve this. i think i need to get js_normalmapper to work, but so far i can only get it to render black at best.

# 68 18-03-2008 , 11:14 PM
LauriePriest's Avatar
Moderator
Join Date: May 2003
Location: London
Posts: 1,001
the contouring issues is your bit depth, you need to be outputting at 32 bit tiff or somthing from z brush, converting the image to 32 bit later on will not help at all.

The hardware normal mapping will be doing things very differently so read up on the nodes and what data types they support. Some nodes may not handle low bit depth etc.

There is an gamma offset value you need to remember which is important to get from zbrush but i forget where to find it, i havnt used it for a while, it basically ensures that with the floating point image maya is looking at the correct value range.

# 69 19-03-2008 , 04:53 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
thanks LauriePriest - yeah - i've been using a 32 bit tiff from zbrush.

i'm pretty sure that the normal map is fine - i can see it in the viewport and in zmapper. i think mental ray is just rendering my normal map as a bump map cos when i used the normal map as a bump, it renders the same.

so i'm not sure if there's something wrong with my bump2dnode. is there something i have to switch on to turn on tangent normals?

i'm wondering if it's a problem in maya 7 - i've seen a few people with the same problem.

i had a look for the gamma offset value in zbrush, but didn't have any luck.

still stuck. user added image

# 70 19-03-2008 , 09:44 PM
LauriePriest's Avatar
Moderator
Join Date: May 2003
Location: London
Posts: 1,001
it may be an alpha offset value, i made some notes from an excape lecture on it ages ago ill check for them in the office tomorrow.

# 71 19-03-2008 , 11:06 PM
DJbLAZER's Avatar
Registered User
Join Date: Jun 2004
Location: Gothenburg, Sweden
Posts: 1,318
Arran, if the tiff file you open in photoshop is in 8-bit then there's your problem... since you said that you're "using a 32 bit tiff from zbrush".

# 72 19-03-2008 , 11:10 PM
GioChrono's Avatar
Registered User
Join Date: Apr 2004
Location: Tunbridge Wells, UK
Posts: 354
either way an 8-bit file should be fine for a normal map any way. I use 8-bit jpgs, it shouldn't create a problem.

Your using version maya 7?

Can you post an image of your shading network?

Gio


Gio

Creator of The Talos Project

# 73 20-03-2008 , 03:16 AM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
LauriePriest - thanks, i appreciate it.

DJbLAZER - yeah, i'm confused - when i hover over the file in zbrush it says 32 bit - but in ps it says it's 8 bit.

GioChrono - yea, maya 7. here's my shading network. i'm sure there's something i'm missing.

haven't had much of a chance to look at this, but i did manage to find a bumpnode for maya 7 on highend that let's me render the normal map, though only in maya software.

Attached Thumbnails
# 74 25-03-2008 , 02:04 PM
arran's Avatar
Registered User
Join Date: Dec 2005
Location: Brooklyn, NY
Posts: 3,708
still not having much luck- it seems that everything i touch at the moment ends up breaking. last night my lcd started messing up. I'm pretty sure that my video card is damaged as i can't seem to adjust any of the settings. i tried reinstalling it and looking for drivers but no luck. so at the moment i'm debating whether to try to put a new one in myself (i'm not much of a handyman) or get someone else to do it. I'm also trying to decide whether i should get a geforce instead of quadro to save myself a bit of money - i'm not sure how different they are. hopefully i'll have some updates soon...

Attached Thumbnails

Last edited by arran; 25-03-2008 at 02:06 PM.
# 75 25-03-2008 , 02:38 PM
younglion's Avatar
Registered User
Join Date: Jun 2005
Location: t-dot
Posts: 646
ohh man that sucks hopefully you get this problem solved

Posting Rules Forum Rules
You may not post new threads | You may not post replies | You may not post attachments | You may not edit your posts | BB code is On | Smilies are On | [IMG] code is On | HTML code is Off

Similar Threads