Wednesday, October 10, 2007

The mia_lens_bokeh shader.

Todays mental ray experiment focuses on lens artifacts
such as chromatic aberration, scratches and blooming/glare.

First of: chromatic aberration.
Chromatic aberration is an artifact often seen when using
low end or wide angle lenses. Due to the colors different wavelengths
and the differing index of refraction on the lens, the color spectra
gets separated, mostly on high contrast parts of the image.
( for a more correct explanation take a look at this wikipedia page )

One way to produce this effect is to use the new
bokeh shader shipped with Maya 2008 (mia_lens_bokeh).
The result produced this way will not be at all physically correct
but will give a similar look to the rendering.

Ok, lets see some example.

Top image image taken with a higher quality lens producing no chromatic aberration.
Bottom image taken with a wide angle lens producing substantional chromatic aberration.

Next let's look at the result we get from our bokeh shader

Notice that we only get the effect on the out of focus regions.
This is due to the use of the bokeh shader which is a depth of field shader.

The setup to get this result is really quite simple.
What you need to edit on the shader is the following:
  • Check the "Use bokeh" check box
  • higher the bokeh samples (or the image will render black)
  • load a color map texture in the "Bokeh" slot
The texture used in the rendering above is a really crude RGB map
that look like this.

Thats all on chromatic aberration for now.


Joey said...

please tell me where I can get this shader ? Thank

Anonymous said...


When ever I surf on web I never forget to visit this website[url=].[/url]Plenty of useful information on Frankly speaking we really do not pay attention towards our health. Let me show you one truth. Recent Scientific Research points that closely 70% of all USA adults are either obese or weighty[url=].[/url] So if you're one of these citizens, you're not alone. Infact many among us need to lose 10 to 20 lbs once in a while to get sexy and perfect six pack abs. Now the question is how you are planning to have quick weight loss? You can easily lose with with little effort. Some improvement in of daily activity can help us in losing weight quickly.

About me: I am writer of [url=]Quick weight loss tips[/url]. I am also health expert who can help you lose weight quickly. If you do not want to go under painful training program than you may also try [url=]Acai Berry[/url] or [url=]Colon Cleansing[/url] for effective weight loss.

Anonymous said...

If you wish for to obtain a good deal from this paragraph
then you have to apply these techniques to your won weblog.

Here is my blog:

Anonymous said...

Have you ever considered writing an ebook or guest authoring on other websites?
I have a blog based on the same subjects
you discuss and would love to have you share some stories/information.
I know my subscribers would enjoy your work.
If you're even remotely interested, feel free to send me an e mail.

my web-site: Revolyn Weigth loss

Anonymous said...

Way cool! Some very valid points! I appreciate you penning this post and the rest of the website is also very good.

my web site: Diet plans to lose weight

Anonymous said...

Great blog you've got here.. It's hard to find high-quality writing
like yours nowadays. I seriously appreciate individuals like you!
Take care!!

My web-site: mouse click the next page

Anonymous said...

Heya i'm for the first time here. I found this board and I find It truly useful & it helped me out a lot. I hope to give something back and help others like you aided me.

my webpage; Diet Patch Review

Anonymous said...

Very nice post. I absolutely appreciate this site. Continue
the good work!

My web page; Green Coffee Extact

Anonymous said...

It's very straightforward to find out any matter on net as compared to textbooks, as I found this piece of writing at this web page.

Feel free to surf to my blog: Best Supplements To gain Muscle

Anonymous said...

Hi there to every body, it's my first pay a visit of this webpage; this webpage contains awesome and genuinely fine stuff in favor of visitors.

Also visit my website: Nuvocleanse Diet

Anonymous said...

Rеmaгkablе! Ӏts іn fаct
аwesome pаragraph, Ι hаve got much сlear іdеa regarding
from this рiecе οf writіng.

my web blоg ... Cheap Sarongs

Anonymous said...

I know this web site gives quality depending articles and other data, is there any other web site which
provides these things in quality?

Take a look at my blog ... acai ultra

Anonymous said...

I every time spent my half an hour to read this web site's posts all the time along with a mug of coffee.

My web site - Ultra Slim Patch Weight Loss Program

Anonymous said...

Highly energetic post, I loved that bit. Will there be a part 2?

My web page pure green coffee reviews

Anonymous said...

Howdy! Do you use Twitter? I'd like to follow you if that would be ok. I'm undoubtedly
enjoying your blog and look forward to new posts.

Look at my weblog ... Buy green coffee

Anonymous said...

Yes! Finally someone writes about line of credit.

Here is my page :: money

Anonymous said...

If you are going for most excellent contents like myself, simply
pay a quick visit this web site everyday for the
reason that it presents feature contents, thanks

my webpage: dark circles under eyes

Anonymous said...

Wow, marvelous blog layout! How long have you been blogging for?
you make blogging look easy. The overall look of your website is magnificent, as well as the content!

my website ... Buy Rejuvenex

Anonymous said...

Fabulous, what a web site it is! This blog gives helpful data to
us, keep it up.

my website -

Anonymous said...

Awesome article.

Look into my homepage ... Personalloan

Anonymous said...

Keep on working, great job!

Here is my site ...

Anonymous said...

In fact no matter if someone doesn't know then its up to other visitors that they will assist, so here it takes place.

my weblog ...

Anonymous said...

You really make іt seеm so eаsy with
youг presеntаtіon but I find this
tоpiс to be actually somеthіng that I thinκ I would never understanԁ.

It seems too complex and vеry brοad for me. I am looking forward for your next poѕt,
Ι will try to get the hang οf it!

Also visit my web pagе :: car insurance

Anonymous said...

I was rесommеnded thiѕ blog bу my cousіn.
I am not sure whethеr this poѕt is written by him as no
one else know suсh detaіleԁ abоut
my difficulty. Yοu аre wonderful! Thanκs!

Revіew my page :: coffee pure cleanse dr oz

Anonymous said...

I got this website from my friend ωho shared with mе on the topiс of this ωeb ѕite and
now thіs time I аm visiting this web pаge and reаding very informative articles at this time.

Нere is my ωebpage :: veloura & bellagenix

Anonymous said...

That is the time that you will be able to use the brave frontier hack generator and 2014 for stone and gold to maximize your gaming experience.

Feel free to surf to my blog post ... brave frontier hack no survey no password