simulated global illumination plugin


#21

Seems really useful. However, I’ll have to come back to this if I ever upgrade my CPU… Darn, and I thought Simbiont Darktrees were slow… Got get me wrong though, it seems like a very cool shader, but it takes like 30 minutes to get a 200 x 200 px image on my poor excuse for a PC :smiley:


#22

Originally posted by JamesMK
…but it takes like 30 minutes to get a 200 x 200 px image

Sounds like the lovely AMIGA days when a single image
needed hours and days. No joke, I had an image that
needed 3 days to render. Sometimes I can barely believe
how fast todays computers are. But they are never fast
enough :slight_smile:

cheers, Bob


#23

yea its not fast but I guess the point is that its faster than radiosity.


#24

jiii you totally got the point…
i mean that image i did still took a while to render but with radiosity i wouldn’t have bothered on this machine!!


#25

Yep, its a nice radiosity fake.

The cool thing is you can bake it to spare even more
time. I just tried it and it works. Very nice for animations
or games.


#26

perhaps its my machine then, which is no longer up to par with todays beasts, but i think it is rendering the AO WAY faster than radiosity and even a dicloner fake…im lovin it


#27

Well, of course, compared to radiosity this thing is really flying even on my machine… I’ll save it for the final render of, er, something!


#28

Thanks stew and anobrin! :beer:

a little question: if turn the COFFEE version to C++ version, will the C++ version speed up the rendering?


#29

Wow, this sounds extremely useful! I’ve been looking for alternatives to raytracing for my animation project, looks like this could be it!

Thanks bobtronic for the tip about animations!

Can’t wait to get home and play with this! :slight_smile:

Pate


#30

I played a little with this plugin now and I really like it.
You can get some nice results with carefully tweaking
and compositing. This is a little test I made:

http://home.snafu.de/bobtronic/misc/ao_01.jpg

Only one lamp, cool

thank you stew

Bob


#31

From what I read, speed was one of the main motivations for AO. It has been used in a couple of feature film productions, where Radiosity is just too slow. Though I think many productions use a shadow mapped version of it and bake it to textures.


#32

ILM were the ones to develop the Depth Map Based Ambient Occlusion Lighting setup in PRMan. It is fast and it can produce image based lighting like with HDRI. This setup was used in HULK.

for every object, you render a pass or texture map which determines how much ambient light hits any given point on a surface. This level of ambient light is independent of the actual light source used to illuminate the scene. The ambient light is then calculated by applying an environment map of the scene into which the object is to be integrated. This ambient light is attenuated by the previously rendered ambient occlusion pass.

A further development of this technique is that of the “average light direction vector” usually refered to as a bent normal vector. This is an additional pass in which the R, G, and B values of the image do not represent physical colour but instead are used together to make a vector which the surface shader uses to “bend” the currently shaded point’s normal so that it “looks at” the position on the environment map from where the majority of light came from during the ambient occlusion render pass.

You can read more about it from the following link

http://www.andrew-whitehurst.net/amb_occlude.html


#33

heres my latest render with the plugin on a hypernurbs model i created a few months back

I LOVE this plugin!!!:buttrock:


#34

This is a wonderful thing :thumbsup:

Did a quick composit with AO and a regular raytrace render (method can be found here on CG talk, just search on ‘ambient occlusion’)


The overexposed look to create a white background was done on purpose using levels in PS.

Total rendertime of both passes 640x360 <15min :). High-quality radiosity renders (as on my site) took several hours. Although you cannot really compare the quality ;).

I rendered 50frames of an AO-pass at 400x225 in under two hours. Unfortunately the flickering is too bad but even with double rendertime and acceptable flickering you won’t here me complain.


#35

You can reduce the noise by
a) increasing the number of samples for AO
b) increasing the AA samples in the C4D render settings

I am considering adding an option to a future version that will let you trade noise for aliasing by disabling the jitter.


#36

Originally posted by stew
[B]You can reduce the noise by
a) increasing the number of samples for AO
b) increasing the AA samples in the C4D render settings

I am considering adding an option to a future version that will let you trade noise for aliasing by disabling the jitter. [/B]

Did some optimizing on the car (lowering hN subdiv) without losing quality at this resolution.

AO-pass 640x360: 4min36sec
Raytrace pass 640x360: 1min20sec

I’ll try upping AA and AO-samples :).


#37

Originally posted by stew
[B]You can reduce the noise by
a) increasing the number of samples for AO
b) increasing the AA samples in the C4D render settings

I am considering adding an option to a future version that will let you trade noise for aliasing by disabling the jitter. [/B]

Stew, thanks for the plugin. Would a transition from COFFEE to C++ improve the speed, and is that practicable?

Nick


#38

I’m busy typing a short tutorial:

-usage of the AO-shader
-simple three-point-lighting setup
-rendering two passes and compositing them in photoshop
-settings and some tips

That were used getting this result:

GREAT shader Stew :applause:


#39

That looks great handige, what was your final rendering time?


#40

Well it’s done, boy is typing html tags boooring :scream:

http://www.shademaster.nl/peter/ao-tutorial.htm

Please give some me feedback :).

tjnyc: you can find the answer in the tutorial

Stefan be happy to use my image or tutorial on your site :).