Mental Ray/GI Joe rendering
 

I've noticed that many people get a really nice fuzzy/matt finish on their models, and they seem to be using either GI Joe of Mental Ray. I have mental ray, but still cant get that lifelike matt look.

How exactly do I achieve this look?

I am hoping that one of the guys such as brian or brian LOL - can do a little walkthrough on this as it would help a lot. I get a lot of mails asking this question...

Most seem to be able to set it up and get the GI dome and then are not quite sure on futher render settings, like where they go next ...

If I have time Ill try to do one but I would much prefer someone who uses it all the time :D

Thats who I was mainly referring to, the models look so lifelike, or like real sculptures, its incredible.

I just ant get that quality on my renders!!

not exactly sure what you want, but this is the way i light:

main light (spotlight):
cone angle: 60
penumbra angle: 20
dropoff: 5

use depth map shadows (important for that fuzzy look)
dmap res: 512 or higher
filter size: 4

try that :)

I think it might be usefull to do like a

1. open your model
2. press your GI button
3. apply the following settings.
4. bla bla
5. bla bla

so it takes you through nem... right to the end

get me?

This should get you started. It's my old thread with loads of tips from Brian.

http://forums.simplymaya.com/showthr...&threadid=3533

here ya go :) i was going to do this earlier but i was busy with my biology, but 5 easy steps to soft shadows without the use of GI Joe or mental ray, just maya :)

1. model a simple scene, i have a plane, sphere and a cube and position them like below

2. create a spotlight, and with it still selected, in any viewport click on panels>look through selected and position the spotlight so its like the image below (this just allows you to see shadows easier, you can put the light anywhere you want)

3. with the light still selected, hit CTRL+A which will bring up the attribute editor and use the following settings for the light:

cone angle = 40 (this is how far the light will reach, the size of the light cone if you will :))

prenumbra angle = 20 (this is the distance from the edge of solid light to the point where theres no light at all, how far it fades basically)

dropoff = 5 (this is the intensity at which it fades the light edges

check the box that says use depth map shadows

dmap resolution = 400 (this is what i would define as blurriness, the lower the number the blurrier the shadow)
dmap filter size = 4 (i think this is the quality of the shadow blur, if you turn it down it looks crap)

3a. If you look through the spotlight again you'll see that it has changed, this is because you've changed its attributes :) (you can also do it with the show manipulator tool)

4. Now open up the render globals (which is two buttons to the right of the render button in the status line) and make sure anti-aliasing quality is set to production

5. now you hit the render button and voila :) soft shadows :)

i know you've been asking about GI Joe, but you can get soft shadows without GI Joe, if you want soft shadows on a character (like shadows on a characters neck caused by its head or something), this method also works, just model something complex and you'll get what you get with GI Joe (well, almost, GI Joe is global illumination, theres a difference)

I use this method mainly for ground shadows, but for self shadows (like on a character) i would use GI Joe, which is amazing cos you can use both methods (dmap shadows and GI Joe) together and itll look amazing, trust me :)
i can do another short tut on GI Joe if you want, but you'd have to provide the model cos i cant model :(

heres one with a white background, now you can see the dropoff of the light on the plane, see how it fades into black?

two more :)
the building shows how it can implemented with GI Joe (not too well, but you can see the shadows and that)

the bear shows character self shadowing without GI Joe

Hey thanks, that was very helpful, I am actually getting some nice looking scenes now.

But another problem I am having is that I cant get GI Joe installed properly. Does anyone have a link to the download and a good tutorial?

Thanks

http://www.3dluvr.com/pixho/

this is the site of the creator of gi joe, you can download it from there and theres a tut on there on how to download it

Thanks again, check out my first render using your technique! :)

My first ever proper Maya render! Yay.

hey that looks prettty cool :)
if you use the technique above with GI Joe, i reckon thatd look pretty amazing

or if ur lighting stuff that doesnt require GI, you could try three point lighting

I'm really new with all this, I cant even get GI Joe to work.. lol. Its not easy to load like mental ray.

Three point lighting?

oh ok, sorry
im not that big on the installation of GI Joe, i had a few problems with it when i installed it, try the link NitroLiq posted earlier

three point lighting:
basially, this is a very simple but important lighting technique, i cant remember the xact names, but you have a main light which casts shadows (using the technique above) then you have a back light which would light the scene from the back (low intensity) and a fill light coming in from the side (low intensity again) it just fills the scene up with light like its natural lighting (but of course GI Joe does this anyway but sometimes you can achieve the same effect using 3point)
if you give fill light a slight pale orange colour, and the back light a violet colour it wud look pretty good, like the sun and mmm :)
its hard to explain, try doing a search for it on the web, im sure you'll find something

Hey thanks for the fast reply :)

When putting in three point lighting, which is the best light to use for each? Right now I'm just using a spotlight for shadow projection.

spotlights, i use spotlights to light all my scenes, sometimes i use point lights, i hardly ever use any other lights :)

in one of the old issues of 3dworld there was a video about 3point lighting, you might wanna take a look at that as what i said earlier probably wasnt entirely accurate, actually, ill take a look at the vid now for you, ill post back :)

3 point lighting:
use it as a basis for scenes, you can always add more ontop of it :)

create a spotlight (main light). the main light should be more elevated above the scene than the other three lights (like the sun). change its colour to "eggshell" like. This light should have a high intensity so the other lights dont over power the scene. use the same light attributes as above to test out the light, you can change everything afterwards :)

create another spotlight, this is the secondary light source. change the colour to "pumpkin orange". this light should be comin in from the opposite direction than the main light. this light adds "mystery" to the scene. low intensity. use the light attributes stated earlier

create another spotlight (fill light). because we've already got 2 warm lights, we want to balance the scene out with a purpley colour (dark purple so its not too bright). position this light between the two other lights low intensity. use the light attributes stated earlier, altho you dont have to use a shadow in any of the lights apart from the main light.

the light colours can be changed to what you like (buti like the colours above).
dont forget, you can always add more lights to the scene to fill it up as needed, it really is all about experimenting :) 3 point lighting is essentially 3 lights at different angles :)

this is a really fast lighting method compared to global illumination and will give you almost the same effect (if used correctly)

Nem, is right. You can get get great results just starting with 3-point lighting and going from there. The render time is much quicker. The problem is, people see some great renders and hear that the person used GI_Joe then all of a sudden think it's going to be the end all solution to make beautiful renders so they have to have to check it out. I did the same thing.

One thing that makes me curious is if you have mentalray for maya, why do you need GI_Joe? GI_Joe is a script to compute pseudo global illumination. Mentalray with Final Gather is the real deal. Render times can be a little long depending on the amount of rays used but the results can be worthwhile. You might want to look at these tutorials:

Global Illumination in Maya (with MentalRaya 1.5)

Caustics and surface scattering with mentalrayFinal Gathering in Mentalray

Mentalray - Faking HDRI

Caustics in Mentalray for Maya

Various mentalray tutorials

i think a lot of people go with GI Joe because:
1. they dont have maya 4.5 (i dont, thats why i use GI)
2. they see other ppl using GI Joe, like you said
3. and thats all i can think of :)

mental ray is also weird because its not part of maya if you get what i mean, its an external program called in by maya, whereas GI Joe is an actual mel script

That's true but I'd think if you're going to spend the time to learn an application as deep and intensive as Maya and you have a great renderer such as MR, that'd be a given to delve into it deeper. I can understand though if you're not running 4.5. GI_Joe is definitely quicker to get up and running with. I still use it from time to time.

i can understand that :)
one thing really really annoying about MR is you cant render things like fur, paintfx etc, but you can with GI_Joe because thats just a lighting system, not a renderer :)

for those just starting with maya, stick with it until you learn a lot more about it before jumping in with two feet into a pool of unknown substances that could eventually drown you :)

Hey guys perhaps one of the biggest reasons why ppl prefer using GI_Joe over MR is because of the render speed. MR is so damn slow in comparison when it comes to GI.

Nem u say u hardly ever use anyother lights other than spots. I think alot of ppl approach it this way too. Only thing is, its probably not the best attitude to have when it comes to lighting for specific purposes. For example, directional lights are best used for outdoor scenes when u r trying to represent sunlight. When u use point lights, as in ur example...the angle of the shadows arent correct cos u find u have to position the point light so far away from the scene in order for it to light correctly. So the shadows kinda appear flat. Its a lot harder to create accurate sunlight from a point light.

But u r spot on (no pun intended lol) about using the 3 point lighting system as a basis to work from.

Lighting I think is the most important factor in making ur work move from adequate to top notch. If u have a great light setup, it improves the quality of ur render output no end :)

And yes...I think ppl should practice with creating their own light setups rather than just diving headlong into GI_Joe and what have u. It bodes better for the future. GI_Joe rocks tho!

Great examples in this thread Nem - top man!!

Thanks everyone, I cannot beleive the number of great members on this board ready to help out.

Nem, I'm going to try your tutorial on 3 point right now.

And Nitroliq, thanks for that. I saw some GI Joe renders and thought I needed it, but I'm getting close results with mental ray now, just the render times are quite slow.

Okay, here's the scene with 2 point lighting.

and now with 3 point lighting, I love the new mysterious feel to it :)

A close up 3 point render, 1024X768 using Maya Software render.

It actually looks really nice now, Im getting a few artifacts with the floor lighting though, the same as you were getting in Brians GI rendering thread. Notice the shaded lines on the ground?

Any way to get rid of this?

hmmm, weird, try turning the dmap filter size up

Well, I upped the Dmap from 400 to 500 and that helped a lot, but to get completely rid of the artifacts I need a Dmap res of 700.

Thanks for pinpointing that problem so fast!

there are so many settings to play with when it comes to lighting. i was actually talking about the dmap filter which you had set to 4, but if the dmap res works, then stick with that :) but u wud lose softness if u turn the res up

Ahh, I'll toy around with that now.

Okay, I wanna jump in here now. ;)

I'm still working on my renders of my first short film and tho they don't totally suck yet, I'm having trouble getting that GI look I'm really going for. With the picture I added below, I'm using RealFakeGI shaders, GI Joe and various lights in the scene suggested from a book I bought called the Maya 4.5 Handbook. I love the room layout and the way Adam Watkins mentions using Area lights above my sconces to reflect the creation of "bounced" lights. For the sconces themselves, I'm using Point lights.

I have three spotlights above three poster frames and I'm not sure using Nem's techniques on all of my lights in the scene would work for good GI lighting. I'm kinda frustrated here because I know I'm on the right track... I just ain't connecting here. ;P Do I need to get rid of all of my RFGI shaders and just use GI Joe or get rid of GI Joe and use the shaders with Nem's technique? Can I do this and get a bit of an eerie feel to my scene.. unfortuneately, it's an indoor scene. :( If you guys and gals have any good suggestion, please holler! :)

Thanks a mill!
Russell

i wudnt use realfake with GIJoe because they both do the same thing, just use GIJoe
and i only tend to use mytechnique when i need to case long shadows, for everything else i just use GI Joe

Hmmm... okay, I got rid of RFGI and made a few changes to the dmap settings and this is what I came up with. I still think the lamp is too bright but over all, I think i like the darkness in the scene. Should I up the Intensity of the GI Joe setup?

Russell

BTW, a good setting for dmap resolution and filter are 64 and 3 respectively. :) Just FYI...