AO or dirt map?

[kuui]

for faking GI i'll rather use AO, as AO gives every point kinda a basic brightness AFAIK, something dirt doesn not do (which is the difference between the two).

also you can render the AO pass out once and composite it with any rendering that uses the same camera. it's slow but you need to render it only once.

[SteveB]

Hi - would you mind elaborating on this process? I havent tried this method before and wouldnt know where to start?


Steve

[Simon Wicker]

what do you guys think the differences are and when would you use one over the other?

hi strat,

you have to use the AO shader for this kind of thing because the Dirt shader ignores your Geometry AA settings (so the edges of the objects in your scene will all be ragged in the dirt pass).

cheers, simon w.

[AdamT]

You can use the dirt shader, but it takes some work. You'll have to bake it first. What I've done before is save the scene under a new name, connect all the objects I want "dirted", apply and bake the dirt shader. Render a material pass and add slight blur in AE to reduce grain. Multiply the dirt pass over the full render in AE.

[Blur1]

Guys, is there a default AO shader supplied with C4D now? I just bought R9 and haven't found it in the shader list. I thought you had to use ambiente or the dirt shader.

[AdamT]

The dirt shader is an AO shader--just not a very good one.

[lllab]

just download the free ao shader from bobtronic, if you play with the settings it has good speed, add a little blur and composite.

i do that all time, one ao pass, one atmospheric pass, one image pass, often one s&T pass-
works very well animated and still.

cheers
stefan

[Blur1]

Right so there is no other AO shader except the ones I was already using. Just checking.

[STRAT]

heers for the responses fellers. i guess AO is the correct route then. it's just painfully slow compaired to dirtynutz thats all.

[nycL45]

Fascinating upper class lesson. Thanks.

Lower classmen, it is your assignment to come up with the what, why, when, where and how for the following:

...also you can render the AO pass out once and composite it with any rendering that uses the same camera. it's slow but you need to render it only once.
...connect all the objects I want "dirted", apply and bake the dirt shader. Render a material pass and add slight blur in AE to reduce grain. Multiply the dirt pass over the full render in AE.
...one ao pass, one atmospheric pass, one image pass, often one s&T pass-
works very well animated and still.

You have one year from today to complete the assignment. Those failiing to do so will be subjected to punishment selected and meted out by the aforementioned upper classman.

Good luck.....

[Simon Wicker]

heers for the responses fellers. i guess AO is the correct route then. it's just painfully slow compaired to dirtynutz thats all.

which version of the shader are you using? there is an old coffee version and a new compiled C++ version - the new compiled version is faster.

cheers, simon w.

[STRAT]

which version of the shader are you using? there is an old coffee version and a new compiled C++ version - the new compiled version is faster.

cheers, simon w.

you couldn't obige us with a new link here please m8? only i be mostly a lazy sod :p

[lllab]

search the net for bobtronic, there is also ambiente2, written in c++
( i think its www.bobtronic.de or something)

cheers
stefan

[Simon Wicker]

you couldn't obige us with a new link here please m8? only i be mostly a lazy sod :p

here:

http://www.bobtronic.de/plugins/

click on the ambiente2 link in the cinema 4d 8.5 list.

cheers, simon w.

[VestanPance]

You can also get the V3 beta here:

http://www.bobtronic.de/files/plugins/beta/ambiente/

[STRAT]

ta guys, that v3 is light years faster :)

[pid]

hi bobtronic,
is there a change to get a mac version of AO. V3?

cheers Pid
Berlin

[STRAT]

unfortunately, the AO shader is completely useless for large archi scenes. it doesnt even come close to doing it's job. the results it renders are completely unusable. i've had to go back to the dirt shader :(

[Simon Wicker]

unfortunately, the AO shader is completely useless for large archi scenes. it doesnt even come close to doing it's job. the results it renders are completely unusable. i've had to go back to the dirt shader :(

a description of the problem rather than 'it sux' would allow people a chance to diagnose the error.

cheers, simon w.

[STRAT]

ok, problem description comming up :) -

here's the original scene so you can see whats what. just a small scene to try it out on -

http://www.nikclark.com/strat/test01.jpg





here's the same scene with a quick dirt map pass. looks pretty decent and very usable for shadow comping in photoshop.

http://www.nikclark.com/strat/test02.jpg






here's the AO material pass. not only is it extremely messy, but i cant even extend a decent spread on the shadows.

http://www.nikclark.com/strat/test03.jpg






here's an AO close up. whats going on here? all tried and tested with high samples too. i get this same effect on every archi scene i've tested.

http://www.nikclark.com/strat/test04.jpg

[STRAT]

ok. problem identified. it's a bug.

i model at a scale of 1 c4d unit = 1 mm. so in effect all my models are life sized. and thats the problem. a typical archi scene is WAAAAY to big for the AO shader to work properly.

then i selected the whole scene and scaled it down by a hundred or so. and it worked allot better. not funny patterns. but no consistancy. if i slightly scaled up or down the scene a touch again i'd get different rendered results yet again.

any chance this bug can be fixed to give a standard result?

[Ernest Burden]

I have used the dirt shader, but just the channel one, not the one you bake into UVs. It has worked well, but seems as slow as GI would be. Combine that with some S&T linework and you have a beautiful, but uselessly slow, output.

I'll have to try Bob's new AO.

[STRAT]

the trouble i find with the dirt shader isn't nessessarily the speed, but the face normals. you must make sure all your normals are pointing in the correct direction else you'll get a fair few 'black' spots. it takes a fair bit of fiddling to get it nice.

the 3rd edition of the AO shader is pretty sweet, if they can fix the scaling bug. no need to fiddle with face normals with that.

i wish i had s&t too :(

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