SimplyMaya Forums

Welcome to the forum, feel free to ask questions here.


SM Forums / Maya Questions / Dynamics & Special Effects / Mental Ray rendering multicolored sprites as one color! Why?

Dynamics & Special Effects Maya Particles, nDynamics, Fluids, Rigid Bodies & General VFX

Join the conversation. Reply to post
 
Thread Tools
20-08-2012, 06:20 AM   #1
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
Mental Ray rendering multicolored sprites as one color! Why?
Hi folks.

So I'm trying to get mental ray to render a bunch of STATIC particles that are no longer dynamic. I have assigned a lambert shader to them, with a sequence of seven images, generated randomly at creation via a SpriteNumPP expression. They are shown correctly in the viewport (see first image). These colors are assigned from an image sequence - NOT from rgbPP, and that's how this has to remain.

Now, when I do a Hardware render, the colors are correct, but when I do a Mental Ray render, the colors are all the same (see second image). The color that they will have seems be the current image sequence color, which is not what I want...I want the sprites to keep their various colorations that they show in the viewport. My guess is that MR is reassigning the current frame's image file (see third image) to ALL of the sprites, but I don't know why...

Anyone have an idea about this?
Attached Thumbnails
Click image for larger version

Name:	multicolored sprites.jpeg
Views:	669
Size:	161.1 KB
ID:	52138   Click image for larger version

Name:	same colored sprites.jpeg
Views:	667
Size:	131.1 KB
ID:	52139  
Attached Images
 
  Reply with quote
20-08-2012, 07:40 AM   #2
honestdom
The Nurb Herd
 
honestdom's Avatar
 
Join Date: Oct 2007
Location: London
Posts: 2,381
What happens if you render another frame?
  Reply with quote
20-08-2012, 05:30 PM   #3
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
They will all look the same in the viewport (multiple colors) regardless of the frame number, because their dynamics have been turned off. Static field of particles.

But if I render a different frame with MR, they will all be colored the same - directly related to the lambert assigned to them, and the image sequence they are based on. In that example, they are all a yellow color, because that particular image in the sequence is the yellow one. If I scrub one more frame and do another MR render, the color will change because the image sequence will cycle to the next in line.

I want the MR render to look like the first attached image.

Last edited by scentmental; 20-08-2012 at 05:42 PM.
  Reply with quote
20-08-2012, 09:21 PM   #4
daverave
The thin red line
 
daverave's Avatar
 
Join Date: Aug 2009
Location: England
Posts: 4,472
Not sure if this link is any use..............dave

http://forums.cgsociety.org/archive/.../t-606259.html
__________________


Avatar Challenge Winner 2010
  Reply with quote
20-08-2012, 10:31 PM   #5
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
Quote:
Not sure if this link is any use..............dave

http://forums.cgsociety.org/archive/.../t-606259.html
Thanks for the reply, dave.

That's the exact technique I've been using. I got it from a gnomon pixie dust sprites tutorial. It works well...just not when using mental ray to render. Mental ray seems to ignore the colors of the sprites, and just assign the current frame's image to all of them.

I'd use hardware rendering, but I also need to use depth of field, and HR doesn't support DOF. I can't use software render because it won't see sprites.
  Reply with quote
20-08-2012, 10:47 PM   #6
honestdom
The Nurb Herd
 
honestdom's Avatar
 
Join Date: Oct 2007
Location: London
Posts: 2,381
The only reason I asked what happens on another frame is to see if your image sequence was working.
Without posting the scene it might be hard to figure out what's wrong.
  Reply with quote
20-08-2012, 11:26 PM   #7
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
@ honestdom:

Appreciated! The image sequence is working from what I can tell. I'm attaching my .ma file with a sequence of three images. This is a stripped down scene, with only the elements needed to troubleshoot this problem. If you could, please load it up, scrub a few frames to generate particles, and see what happens when you try to render with Mental Ray.

I'm using Maya 2013 by the way.

Thanks!



edit: Just realized that the attachment didn't go through...here it is
Attached Files
File Type: zip spriteColorProblem.zip (581.3 KB, 42 views)

Last edited by scentmental; 21-08-2012 at 03:29 AM.
  Reply with quote
21-08-2012, 06:54 PM   #8
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
Checking in. I haven't figured this out yet - mental ray still renders all sprites as the same color instead of a mix of the three colors supplied by the image sequence.
  Reply with quote
21-08-2012, 07:03 PM   #9
Gen
Super Moderator
 
Gen's Avatar
 
Join Date: Dec 2006
Location: South FL
Posts: 3,514
Mental Ray doesn't support spriteNumPP, even as late as version 2013, just a heads up.
__________________
- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::
  Reply with quote
21-08-2012, 07:56 PM   #10
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
Quote:
Mental Ray doesn't support spriteNumPP, even as late as version 2013, just a heads up.
Well that's a disappointment. Thanks for clearing this up for me. I guess I'll have to figure out another way to get the effect I want.
  Reply with quote
21-08-2012, 09:08 PM   #11
daverave
The thin red line
 
daverave's Avatar
 
Join Date: Aug 2009
Location: England
Posts: 4,472
Try another way using instances, I have managed to get some thing to work in mental ray see link, this is using 1 emiter and the colour in is black and white................dave

http://forums.creativecow.net/thread/61/856294
Attached Thumbnails
Click image for larger version

Name:	Instance.jpg
Views:	649
Size:	22.7 KB
ID:	52149  
__________________


Avatar Challenge Winner 2010

Last edited by daverave; 21-08-2012 at 09:10 PM.
  Reply with quote
21-08-2012, 10:48 PM   #12
scentmental
Registered User
 
Join Date: Aug 2012
Posts: 22
I will, daverave...thanks!
  Reply with quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Batch Render not rendering... Miralina Maya Technical Issues 1 04-04-2014 12:25 AM
Extremely confused, Batch rendering issue! mouseyflash Lighting & Rendering 0 04-04-2013 11:06 PM
What happened to the Mental Ray? SilverFeather Maya Basics & Newbie Lounge 10 07-12-2011 12:13 AM
Why Maya? haka Maya Basics & Newbie Lounge 21 10-11-2007 11:14 PM
rendering hair with mental ray aanton Lighting & Rendering 2 03-10-2005 11:19 AM