Mental Ray / Transparency

# 1 25-11-2009 , 12:43 AM

Subscriber
Join Date: Apr 2008

Location: NY

Posts: 61

Okay, what I'm looking to do is create a black mesh waste basket. My problem is, the color black makes things transparent so the black mesh texture I'm using wont be seen.

If I wanted a white basket or a red basket, no problem works fine, but because the texture I want to use is black, against the black background it doesnt work. I'm sure there is a workaround, any ideas?

I'm using targas. Maya 2008 and I want to render it in Mental Ray.

Quote

# 2 25-11-2009 , 01:30 AM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

If that's the case then you may need to adjust the colors to make a separate texture for transparency.

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 3 25-11-2009 , 01:34 AM

Subscriber
Join Date: Apr 2008

Location: NY

Posts: 61

Thanks for the reply GecT. That was one of the things I tried doing. I tried inverting the colors and plugging that into the transparency and I did not have any luck. I think I tried every combination possible, but maybe I'm missing something.

Quote

# 4 25-11-2009 , 05:19 AM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Worked fine for me. Personally, I would just use the mia_material and plug my transparency map into the cutout opacity channel (its in the advanced section).

Attached Thumbnails

Click image for larger version

Name: cutout2.jpg
Views: 278
Size: 159.9 KB
ID: 43321

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 5 25-11-2009 , 05:39 AM

Technical Director
Join Date: Feb 2004

Posts: 2,988

You don't need to create another texture. Use the reverse utility node. Connect the out color of the texture to the input of the reverse node. Then the output to the transparency.

Originally posted by GecT
Personally, I would just use the mia_material ...

Originally Posted by

I don't think an mia material would be necessary for this application. The added complexity and features would probably go unnoticed.

Imagination is more important than knowledge.

Last edited by NextDesign; 25-11-2009 at 05:43 AM.

Quote

# 6 25-11-2009 , 06:56 AM

Subscriber
Join Date: Apr 2008

Location: NY

Posts: 61

GecT, wow, thank you for that! I will try it first thing tomorrow!

Quote

# 7 25-11-2009 , 03:16 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Originally posted by NextDesign
You don't need to create another texture. Use the reverse utility node. Connect the out color of the texture to the input of the reverse node. Then the output to the transparency.
I don't think an mia material would be necessary for this application. The added complexity and features would probably go unnoticed.

Originally Posted by

Didn't even think of the reverse node as I don't use it a lot. But I have to disagree about the mia_mat comment. I consider it to be a general shader so I use it for pretty much everything, hence the "personally" preceding my statement, whether jjmacky88 was familiar with that shader or not, it was to let him know the option was there.

Originally posted by jjmacky88
GecT, wow, thank you for that! I will try it first thing tomorrow!

Originally Posted by

No problem. Let me know if it works out.:blush:

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 8 25-11-2009 , 08:11 PM

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

Originally posted by GecT
I consider it to be a general shader so I use it for pretty much everything.

Originally Posted by

Personally I agree.

"No pressure, no diamonds" Thomas Carlyle

Quote

# 9 25-11-2009 , 09:51 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Originally posted by gster123
Personally I agree.

Originally Posted by

That's my swiss army knife woot! Ok seriously, I have pies to bake.

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 10 26-11-2009 , 03:44 AM

Technical Director
Join Date: Feb 2004

Posts: 2,988

I stay away from them as I pretty much stick with software, and do a whole lot of tricks. I find it easier to control it that way. I can also submit it to a render farm without worrying about MR licenses. I also the find mia material more confusing, as well as slower to render.

Imagination is more important than knowledge.

Quote

# 11 26-11-2009 , 05:46 PM

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

If you submitting to a farm why would you be bothered about MR licences, surely its up to the company to provide the licences for you to use, IF they want you to use MR, if the company dosent want you to do the bulk of the work with MR then thats up to them, softwares your only option.

It's not that confusing, just spend a little time with it, the results IMO make it worth the little extra render time it takes.

Then again if you use software most of the time it wont really bother you with MR materials anyway.

I prefer to use MR over software, not that I cant use software I just find MR a lot more versatile, without needeing to resort to tricks.

On a side note if its not a mia I generally use blinn's for everything.

"No pressure, no diamonds" Thomas Carlyle

Quote

Mental Ray / Transparency

Posting Rules Forum Rules

Similar Threads

Topics

Free Courses

Full Courses

VFX News