FG Question

[Jackdeth]

If you make the chair a little incendecent with orange , it will "emit" that color and bleed it onto the floor.

Also, if you look at the glowyness of the image, I would bet that some photoshop work was done on it.

Its always a mistake to try and get a render flawless out of 3D. Most people underestimate the power of very simple 2D fixes to make things look instantly more real.

There is no such thing as cheating if all you want to do is make pretty pictures... Use every tool you can....

[lazzhar]

Jackdeth you're right. But the guys using Final Render are always showing this picture just to say that FR is better than MR. I cannot beleive that it's a simple rendering.
In my pictures (2nd) I used tons of passes, and every thing is rendered in seperate layer. the orange on the floor is coming from a DirtMap conected just to the shader of the floor.
Anyone tryed to do similar picture in MR?

[brunner]

lazzhar, where can i find the full FR image? (or that tiny bit is the whole scene?:) )
or even better, care to post or email the scene? It doesn't seem to be too tricky to do it..just a bit of playing with photon attributes

[lazzhar]

Here is the full picture:
http://www.finalrender.com/products/images/fr_stage1/gallery/grey-orange1a.jpg

[sebast1an2]

hi lazzhar.. you have to use global illumination, not final gathering! fg is a MR-only feature which is computed "one way", techniques like skylight etc. are based on photon emission...

:wise: ;)

[lazzhar]

Yes Sebast, I've just used FG.
But in GI you have to use a light source emitting photons. How to do that in such scene where there is no light direction ? Or we have to use an array of lights?
Thanks.

[sebast1an2]

hmm, you can use a single, large scaled rectangle area light...

[sebast1an2]

p.s.:

Originally posted by lazzhar
JBut the guys using Final Render are always showing this picture just to say that FR is better than MR. I cannot beleive that it's a simple rendering...

final render is definitly not better then MR, but it seems to be that
FR has one single feature that MR doesn't have... a guy from cebas/FR has something posted in the mentalimages mailinglist:

------------------------------------------------------------------------------
This statement is not fully correct, finalRender is NOT using GI calculation methods based on Photon mapping. We
do use similar photon based approaches to render Caustic Light effects. finalRender can use HDRI-Images as accurate area light sources in one single rendering pass, including the creation of caustic effects, created by those images. mental ray can not do this right now as the GI part usually needs some Photons to shoot into the scene. However, I never tried FG alone which
could work somehow.

regards

Edwin braun

Cebas Computer GmbH
-------------------------------------------------------------------------------

sounds bad for MR, but iv'e read that there comes a new, photon emmiting skyshader and some other awesome features in
maya6!!!:bounce: :applause:

[brunner]

with enough skill, one could write a shader that does exactly that:rolleyes:

I would try, but i'm not sure that it's an appropriate task for a first try at writing shaders :)

[sebast1an2]

hi, brunner.. sounds good, but there comes this feature with maya6 and the release seems to be not far away;)

[TomD]

Originally posted by lazzhar
Yes Sebast, I've just used FG.
But in GI you have to use a light source emitting photons. How to do that in such scene where there is no light direction ? Or we have to use an array of lights?
Thanks.

When I need photons in a scene (or just testing the GI) I set the intensity of the light('s) to 0 and let the light emit the required photons.

[Emmortal1]

Could you post the scene file, I'd like to fiddle around with it.

Emmortal

[lazzhar]

I tryed using GI and it seems a good idea to combine GI and FG.
I'll post the scene tomorrow Emmortal1.

[moblur]

Hey all,

Just wanted to give you guys a new technique for lighting skylight (lit from all directions) technique with photons (GI). Create a sphere as usual, apply a regular lambert shader with the required color settings, no self illumination (incandesence) or ambience. Set the dome's global illumination properties to recieve and emit (bounce) photons. Now place a spotlight pointing up into the skydome, with a large cone angle. Have the light emit photons. Turn on global illumination and final gathering and hey presto, you now have photons bouncing into your scene from all directions... I have had some great results this way... hope the quick explanation is clear enough.....

[anoe_nomus]

Originally posted by sebast1an2
p.s.:



final render is definitly not better then MR,
------------------------------------------------------------------------------

sounds bad for MR, but iv'e read that there comes a new, photon emmiting skyshader and some other awesome features in
maya6!!!:bounce: :applause:

MR simply does not offer what other renderers such as brazil have to offer, and YES FR is much better/faster than MR
.... FYI, a port of brazil is in the works for Maya. so MR will be history,:hmm:

[sebast1an2]

Originally posted by anoe_nomus
FYI, a port of brazil is in the works for Maya. so MR will be history,:hmm:

that's totally bullshit! mental ray will never be history... cause this was:

Originally posted by sebast1an2
...sounds bad for MR, but iv'e read that there comes a new, photon emitting skyshader (>>FOR MENTAL RAY!!!) and some other awesome features in maya6..

conclusion: mental ray offers every feature that exist, except this little difference to FR, cause MR can't compute image based caustics... o.k. and exactly this little disadvantage had been solved with a photon emitting shader for maya6! so where is the problem with mental ray? and i swear FR isn't faster if you use the right settings with mental ray...:bounce:

[Jackdeth]

Really? Maybe Weta and ESC should be told of that.

What MR offers is stability and a proven track record doing giant films that looked amazing. Is it missing a few features....maybe. But shader TD can whip almost anything out of it, and it already works with maya. That won't mean I will turn a blind eye to brazil.... but a rendered has to be soild and tight before any studio can embrace it.


...but I do dig brazil look.... :p

this is only good news for us.... Lets keep them all on thier toes...

[sebast1an2]

hmm, could someone list the fatures of brazil???

[brunner]

YES FR is much better/faster than MR
.... FYI, a port of brazil is in the works for Maya. so MR will be history,
Do you have any solid arguments, or you're just trolling us?

All this "my software is bigger than your software" BS reminds me the kids fighting "my dadyy kicks your daddy ass".

Anyway, i'm pretty sure you have no ideea what you're talking about.

[lazzhar]

Here is the file if someone is interested to render a scene like the FR one.
http://lazzhar.port5.com/oldimages/frfg.zip

Here is the rendering as it is.

http://lazzhar.port5.com/oldimages/frfg_tmp.jpg

Let's show them that MR kicks FR ass ;)

[AniMo]

lazzhar all your images and file links are down :(

[lazzhar]

I'm sorry my host is down, i've downloaded all my files to my computer till i find new host.
sorry again.

Edit:I've moved to a new host and changed the links above.

[brunner]

I fiddled with the scene a bit..
I wasn't trying to make a perfect scene, just to mimic the look.

[lazzhar]

It's very nice brunner,How did you do that?
You see the coloor bleeding on the left wall? how to get rid of this effect?

[brunner]

I put an area light in each opening, a big sphere outside so i don't waste the photons, GI and FG.
I've upped the FG rays to 5000, because i didn't have the patience to sit down and tweak it. :blush: As i said, it's more of a test than a finished scene.

I usually adjust the bleeding using the photon shader applied to the material. In dgs_photon's case, less diffuse.

The scene: http://brunner.f2o.org/roomFR.mb

[sebast1an2]

hi brunner, i have downloaded your scene...looks nice but:
"5000 (!!!) FINAL GATHER RAYS???" are you stupid? :applause:together with GI are only 1000rays more then enough...:hmm:

[Jackdeth]

Not if its animated...... FG flickers alot at 1000. Even 5000 won't cut it sometimes.....

[sebast1an2]

yeah it flickers a lot at 1000... but there are some other settings to solve this problem.. not the number of fg rays!

[brunner]

well, i surely didn't want to waste my time trying to imitate another image and tweaking the FG, so i took the short way. Increased the rays.

The point was that mray CAN do that look. that's it. game over.

[sebast1an2]

not at all... till the release of this GI-skysphere shader for MR/maya6 is finalRender a little bit in front of MR... cause this "real world setup" where i'm searching for is definitly not possible together with FG, which is only computed "one way"...

but maya6 kicks ass:bounce:

[ckas]

quick animation test to see if mr flickers...........




http://www.burg-halle.de/~st1074/fishEye.mov


http://www.burg-halle.de/~st1074/fisheye01.jpg

[TomD]

ckas,

impressive :drool: even frame by frame it tied my sense of direction into a moebius knot :surprised

With how many FG rays did you render this animation?

[lazzhar]

Very nice,
Could you tell us how did you do that?
and the Eye Fish? how to do that? a shader?

[LucentDreams]

pardon me for being so naive, but why are you doing a camera animation to test for flicckering, any system nowadays should be able to prevent flickering of camera animation, throuw a couple of objects around in a scene where the same is relatively still and see if theres flicker thats where the real test should be, and trust me I"ve seen Final Gathering flicker plenty.

[Jackdeth]

Thats not always the case. For the film work that I'm doing right now I had a GI test that flickered badly with simple objects...but looked great with the full rez! It turns out that the hard edged cubes caused a problem that my smooth high rez objects didn't have.

And you can always stop the flickering...but at what cost? No one can afford 1000000 FG rays to make it perfect. So its all about shot-specific work arounds....

[sebast1an2]

Originally posted by Jackdeth
..And you can always stop the flickering...but at what cost? No one can afford 1000000 FG rays to make it perfect. So its all about shot-specific work arounds....

hmm, did you never tried the min/max-radius option???

[Gremlin]

I'm no pro, but I took a shot at recreating that scene with MR... i didn't feel like modeling the chair (kinda lazy) so I added spheres instead. (I spent 2 hours tweaking the settings, it was a good learning experience, since i'm not that familiar with mental ray...)

http://www.alouba.com/mentalray_test01.jpg

I didn't know how to do it in maya, so I had to up the color saturation in photoshop. thats all the post that was done on it! :D
anywho, who you all like it!
Cheers
:beer:

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