ambient occlusion without plugins

[mike_sul]

hi guys / gals...

 

is it possible to create an ambient occlusion pass without using any rendering plugin .. i.e. using the standard scanline renderer

 

for exterior and more specifically interior views ..

 

thanks

[Ernest Burden III]

That depends on the software. Which one are you asking about?

[rivoli]

starting from the assumption you're using max (can be wrong, just a deduction based on how many max users frequent cg architect): ambient occlusion can be very easily simulate by a huge dome light surrounding your scene. this light is usually a spherical (or semi spherical) array of spots. there's a script called e-light by ronnie olsthoorn that will do the trick for you, it can be found here:

 

http://home.wanadoo.nl/r.j.o/skyraider/e-light.htm

[mike_sul]

oops .. forgot to mention i am using 3dsmax

 

will the dome concept of lighting work for interior scenes as it does for extrior scenes ...

 

if elight is a possibility , isnt it similar to skylight light type in 3dsmax :?

[Fran]

Hi Mike,

 

If you are using Max 6, you can do this with mental ray and a dirtmap shader. You have to download the shader and configure max so that it will recognize it. If this sounds like something you want to pursue, do a search of CGArchitect for "dirtmap".

 

If you are using Max 7, it comes with a mental ray dirtmap shader already.

[mike_sul]

thanks fran ..

 

do you mean to use mental ray without using gi or photon maps , etc..

because the basic idea of this post, is to be able to create ambient occlusion without resorting to time consuming gi techniques ..

 

as we all know MR is an expensive piece of software when it comes to rendering speeds..

 

so if we can rely just our pure old scanline renderer..

[pixelperfectg]

You could also use a single skylight with FG to create an AOCC pass. Make the skylight pure white and then adjust the FG falloff amounts to something like 0.0 and 5.0 (these numbers will vary depending on the scale of your scene). I'm attaching a quick test render using this setup.

 

Jeff

 

(render time was a little over one minute)

[Fran]

thanks fran ..

 

do you mean to use mental ray without using gi or photon maps , etc..

because the basic idea of this post, is to be able to create ambient occlusion without resorting to time consuming gi techniques ..

 

as we all know MR is an expensive piece of software when it comes to rendering speeds..

 

so if we can rely just our pure old scanline renderer..

 

Yes. The whole point of an AO pass is to fake GI, or use it to enhance a GI pass with low settings and high filtering. Here's a link that explains it. I found it in 5 seconds via search.

 

http://www.cgarchitect.com/vb/showthread.php?t=5940&highlight=dirtmap

[abicalho]

Just a reminder that MAX 7 ships with an Ambient Occlusion shader for mental ray.

 

Alexander