composite problems PS

# 1 29-01-2012 , 03:32 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

Ok,

did the AO render and then the colour render in Maya...saved as PNG and brought them into PS to make a composite image. All is good UNTIL I flood the background with my black colour and then I get this bloody white line all around the image....should I be making a mask first or some other Warlock magic????

cheers bullet

Attached Thumbnails

Click image for larger version

Name: Openbay_Combined copy.jpg
Views: 245
Size: 205.8 KB
ID: 50328

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 2 29-01-2012 , 03:53 AM

Subscriber
Join Date: Oct 2011

Posts: 139

might be that the images aren't aligned properly?

EDIT: Have black background already in place, to see the contours better. Hold CTRL when you bring AO on top of the regular image and it will make it snap to the edges of the screen, you can also use keyboard arrows to move the AO layer pixel by pixel.

Last edited by nov2011; 29-01-2012 at 04:02 AM.

Quote

# 3 29-01-2012 , 04:07 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

did that nov......its even there without the AO...just the colour image and the background have the halo....bloody thing...thanks mate...will try one more time with your clues

cheers bullet

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 4 29-01-2012 , 04:31 AM

Subscriber
Join Date: Oct 2011

Posts: 139

I just looked over my old model and I have exactly the same thing happening. The problem is that the OA has this edge on in some spots, and also the AO render is a pixel off from the original render. I don't know what caused it.. maybe that's just AO or maybe cause I didn't use render passes, I just rendered my scene twice..Try re-rendering using passes, or you can try using a gray background - then the line won't be so visible.. Sorry I can't be of more help..

If it's just one image you're rendering you pick magic wand, click outside the AO layer, select inverse (so now the model is selected), use eyedropper tool, pick the color right next to the line and re-color the white line. It will take a mintue..

Quote

# 5 29-01-2012 , 04:37 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

Yeh I have it in most too mate. I have a whit background for the AO...I will try changing it too black for the colour render...I render twice too as I have never used passes and probably wouldnt get it right LOL. Done the line thing too but the picker is picky LOL...so is the wand...I will try the aforementione background change

cheers bullet

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 6 29-01-2012 , 04:46 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

got it nov...I expanded the pixels by one then hit flood on the remaining line...might have lost some edge quality...but at least no Halo LOL

Attached Thumbnails

Click image for larger version

Name: Openbay_Combined copy2.jpg
Views: 247
Size: 199.0 KB
ID: 50329

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 7 29-01-2012 , 08:01 AM

The Nurb Herd
Join Date: Oct 2007

Location: London

Posts: 2,381

Hey bullet, you get this because you need to premultiply your alpha. I'm afraid I don't know if you can in photoshop. Its not really a good program for compositing. Maybe it happens because you rendered as png? I would say that the alpha being unpremultiplied is definitely the problem tho.

Quote

# 8 29-01-2012 , 08:45 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

thanks dom...I will have to look into that. PS is the only program I have LOL. I got it eventually but jeez what a pain!!! damn composites LOL...and they arent even for me bahahahahaha. I do need to sort it though...less render times and they look nice when they are done. I even have a little program that I used to add some spec to it outside of maya which was nice

cheers bullet

Attached Thumbnails

Click image for larger version

Name: Openbay_Combined_Spec_Added.jpg
Views: 234
Size: 205.7 KB
ID: 50330

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 9 29-01-2012 , 09:24 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

is this what you meant dom???

cheers bullet

https://www.digitalartform.com/alphaChannel.htm

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 10 29-01-2012 , 10:32 AM

Subscriber
Join Date: Jan 2004

Location: Bolton - UK

Posts: 2,457

The edge problem is most probably the "premultiply" option is switched on in mental ray (render settings> mental ray tab > quality > Framebuffer) Just turn it off.

Edit:, See here for more info

https://www.pixelcg.com/blog/?p=498

This problem used to drive me nuts on the "virtual city" challenge

Last edited by tweetytunes; 29-01-2012 at 10:36 AM.

Quote

# 11 29-01-2012 , 10:48 AM

Lifetime Member
Join Date: Feb 2010

Location: Australia

Posts: 4,255

hey Tweety!!!! cheers mate....learning learning LOL. How have you been man? dig the new bot by the way...and NICE score on the ebay!!!

cheers bullet

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Quote

# 12 29-01-2012 , 10:55 AM

Subscriber
Join Date: Jan 2004

Location: Bolton - UK

Posts: 2,457

Im cool thanks.

Slowly setting in to the new life, just trying to get some of it back - starting with Maya hehe

I learn something new every-time I turn Maya on - means I forget a lot of stuff as well but those the breaks.