PDA

View Full Version : Challenge #1: Fruit Bowl - Tutorials & Breakdowns


jeremybirn
01-14-2006, 09:54 PM
Now that a lot of you have scenes with all your lighting & settings in it, how about sharing how you did it with the rest of us?

A tutorial could show how you approached lighting your lighting challenge scene, in whole or focusing on any tricky or interesting part of it.

A breakdown could just show what the different lights did, just showing their position and the scene lit by each light in isolation, and also breaking down before/after any key effects like occlusion or GI or SSS. If you did compositing, showing the raw passes would help.

Once we get a web gallery going of challenge entries, we can link to them off of that gallery. Contact me if you have an interesting breakdown or tutorial and want hosting for it, they'll all get linked off the challenges gallery.

-jeremy

Samo
01-14-2006, 11:15 PM
Well, that is my simple yet effective 3P lighting setup.



Key light from a supposed windows at the right behind the scene, blue color simulating blue difusse skylight passing through that window. Arealight.

http://img366.imageshack.us/img366/5873/render1k9qg.jpg



Fill light, left and below the camera angle, simulating a hot light source, like a fireplace. Point soft light.

http://img366.imageshack.us/img366/3319/render1f0wt.jpg



Rim light, I'm not that sure about this one, contaminates the fruits models a bit... but on the other hand separates fruits from the background. Arealight.

http://img293.imageshack.us/img293/4336/render1r9gw.jpg

Scene setup:
http://img293.imageshack.us/img293/9467/setup2bx.jpg


here the result:
http://forums.cgsociety.org/showpost.php?p=3029781&postcount=93

ACamacho
01-16-2006, 11:14 AM
There's not much to breakdown in my shot. But hopefully you guys will get something from it.

Occlusion Pass:

http://www.angelcamacho-torres.com/files/fruit_OCC.jpg

Key:

http://www.angelcamacho-torres.com/files/fruit_key.jpg

The SSS type of effect is done through the shader (ramp)....which is why the banana is glowing. :)

Fill:

http://www.angelcamacho-torres.com/files/fruit_fill.jpg

RimLight:

http://www.angelcamacho-torres.com/files/fruit_rim.jpg

The rims were done through a "hack" that one of my friends had come up with. While I can't show his exact setup (it's math driven), I created a light that uses a different setup and works the same way. Basically it's a ramp driven by a samplerInfo Node plugged into intensity of a spotLight (or any kind of light). You get nice rims and don't have to fiddle with light placement too much.

One of the things I missed from switching from Max to Maya was the Gradient Ramp. I know that Maya has a ramp also, but the one in Max had an option to have a light drive the gradient. Everyone who uses Maya probably already know this.....but I found that if you use a surfaceLuminance node plugged into a ramp (with a clamp node in between), it creates this effect. I can post a picture of both the rim and ramp network if anyone is interested.

Well anyway, here is the final result after tweaking the color and added slight grain:

http://www.angelcamacho-torres.com/files/fruit_comped.jpg

Here is a viewport grabof the setup:

http://www.angelcamacho-torres.com/files/fruit_wireframe.gif

yohann
01-22-2006, 12:51 AM
Well... I imagine my scene in the controlled situation, like a studio. I started defining my key light with a golden color:

http://www.yohann.com.br/3D/lc/r_KLight.jpg

Now the next step was the fill light, i work shadows with a litle resolution... a variation between 70 and 150 and 3 or 4 for Filter Size. Speculars light off.

http://www.yohann.com.br/3D/lc/r_FillLight.jpg

So i started work with specular, i think the specular is very important for light compose and add more details in scene, to work independent of diffuse light have more control and many possibilities. So my intent was creat a refcletor with blue gel, with a so weak intensity what is only possible see your bright reflected by objects.

http://www.yohann.com.br/3D/lc/r_SpecularControl.jpg

Observing the scene light i creat too a Rim light but based in ambient reflection like a radiosity but more strong.

http://www.yohann.com.br/3D/lc/r_RimLight.jpg

For to fonish one more light to disconnect the background of all scene, in this light there is a mask painted in photoshop in Colors Light slot to cut the light, made a singular disgned for the background.

http://www.yohann.com.br/3D/lc/r_BackgroundLight.jpg

The light setup:

http://www.yohann.com.br/3D/lc/fruit_bowl_lightsM.jpg

The final render [Maya and Photoshop (only for mask light and fabric texture)]:

http://www.yohann.com.br/3D/lc/fruit_bowl_yhnn_02.jpg

Thanks for all. And more one time: sorry for my bad english. :)

Samo
02-03-2006, 02:26 PM
Hi Jeremy, I'm quite interested in seeing your fruit bowl breakdown. Thanks in advance.:)

jeremybirn
02-04-2006, 11:32 AM
OK, here we go. The final image:
http://3drender.com/challenges/Fruit_test4.jpg

Here's the master layer (ie. all the lights visible at once) in wireframe:
http://3drender.com/challenges/fruitbowl_breakdown/lights.jpg

Here's a perspective view of the reflection environment, shown with hardware texturing: a sphere with a room image, and a card for the window, the card is set much brighter to represent sun filtering through closed blinds:
http://3drender.com/challenges/fruitbowl_breakdown/reflections.jpg

I rendered this image at 2400x3000 for print use ;) so you can really see all of the detail in the reflections. Here's a full-res crop of a cherry:
http://3drender.com/challenges/fruitbowl_breakdown/full_res_crop.jpg

-jeremy

jeremybirn
02-04-2006, 11:34 AM
Here are the beauty pass and "truth" pass - I know those are strange names, but the truth pass has the area light right where the window surface in the reflection is positioned, the beauty pass has it cheated more to the side so it shapes the fruit a bit more. Instead of doing light linking for the two key light angles, I just rendered passes for the two positions and blended them with a layer mask in Photoshop.

http://3drender.com/challenges/fruitbowl_breakdown/beauty.jpg | http://3drender.com/challenges/fruitbowl_breakdown/truth.jpg
Beauty | Truth

I was actually tempted to do a third key angle for the plums in the back, because when frontally lit they tend to look more like flat circles than fully defined spheres, but I kindof liked the "starry night" type texture on the plums as the background of the fruits and decided to leave them with just the beauty pass shading.

http://3drender.com/challenges/fruitbowl_breakdown/plate_spec.jpg
Two of the lights labelled as rims above were really spec lights linked to the plate, to bring out the metal flake pattern in Master Zap's carpaint shader.

http://3drender.com/challenges/fruitbowl_breakdown/rims.jpg
rim pass

http://3drender.com/challenges/fruitbowl_breakdown/fog.jpg
fog pass

http://3drender.com/challenges/fruitbowl_breakdown/gi.jpg
GI pass

http://3drender.com/challenges/fruitbowl_breakdown/occlusion.jpg
occlusion pass

http://3drender.com/challenges/fruitbowl_breakdown/ambient.jpg
ambient pass

http://3drender.com/challenges/fruitbowl_breakdown/bg.jpg
bg layer

http://3drender.com/challenges/fruitbowl_breakdown/bg_ambient.jpg
bg ambient

That's all I rendered as full images. When doing photoshop work, I went back and rendered crop regions of specific fruit areas for fixes that got pasted in: there was a reflection fix where there had been a gap between the cloth and the hemisphere being reflected that needed to be filled in, I rendered a chrome version of the apple and orange to get more reflection and comp some extra glossiness on them, I redid the end of the banana with a new transparency mapped texture that I was glad was a fix layer because it wouldn't have worked in the occlusion pass, I did a separate pass to build in more of a banana reflection in the left side of the plate, probably a few other quick things bouncing back into Maya just for partial images. That's about it.

-jeremy

swag
02-04-2006, 02:28 PM
wau jeremy thats a great breakdown ... can you tell a bit about the gi pass how you do this pass and what is the composite math - thanks :thumbsup:

jeremybirn
02-04-2006, 02:46 PM
wau jeremy thats a great breakdown ... can you tell a bit about the gi pass how you do this pass and what is the composite math - thanks :thumbsup:

There's a checkbox in Maya 7's render pass attribute editor, under Render Pass Options, for rendering a Global Illum pass. It gives you the GI without any of the direct light. (You could also render once with GI on, once with it off, and difference them to get the same thing.)

A straight "add" is the most correct way to composite it, although I think I used "screen" because it's more gentle.

-jeremy

Alfredo G.
05-07-2006, 04:52 PM
Key:

http://www.angelcamacho-torres.com/files/fruit_key.jpg




How did you get this painterly effect with the key light? The curtain in the background looks like a fresco... Really cool effect, your finished result is my favorite so far.

silvia
05-11-2006, 12:34 AM
Jeremy, can I ask you how you got the fog pass and the GI pass?
Thank you.

jeremybirn
05-11-2006, 06:17 PM
Jeremy, can I ask you how you got the fog pass and the GI pass?
Thank you.
Scroll up a bit for the answer about the GI pass.

The fog pass just has a black shader applied to all the objects and is lit only with a Maya spotlight with dmap shadows and default Light Fog.

-jeremy

silvia
05-11-2006, 06:57 PM
Sorry, you are right, I missed the GI pass. Thank you for explaining the fog pass, I never heard of it before.

gerardo
05-12-2006, 05:28 AM
I don't see any fog effect in his render, so I guess he is using this pass (fog pass) as alpha for his ambient pass to fake some SSS effect (it's cheaper and very effective). If we use RPFs, PSDs or some format that store IDMaterial buffers, we can adjust this effect per surface; which is an interesting technique, I think. Although I'm just supposing he has used it in this way :)



Gerardo

PLxKARL
09-07-2006, 02:14 AM
Hi Angel,

Really nice work. I'm interested in seeing a picture of both the rim and ramp network that you said you could post. Also if its not much trouble, could you explain how did you get that noisy effect on the cloth, just with the key light? Thx.

Karl

ACamacho
09-11-2006, 01:16 PM
I apologize for the late reply. Work work work :)

Anyway I posted a breakdown of my candle image in the new lighting challenge.....kinda addresses the rim light and light gradient workflow:
---------------------------------------------------------

Wanted to show the rim light pass because I have gotten some requests on how I achieved the "painterly" look in my fruit bowl entry (and it's also here albeit more subtle) and the rim lights in general. It's actually very simple to create:

Rim Light:

http://www.angelcamacho-torres.com/..._mayaSW_rim.jpg (http://www.angelcamacho-torres.com/files/challenge/candle_mayaSW_rim.jpg)

Shader setup:

http://www.angelcamacho-torres.com/...ader_screen.jpg (http://www.angelcamacho-torres.com/files/challenge/shader_screen.jpg)

This is the basic setup and by no means do I take credit for both of these (good friend of mine had shown me the rim technique although his is a bit more complex). I add a multiply node before I plug the rim into the surfaceShader to kind of act like an intensity value. I try not to use the light gradient by itself but combining it with my file/2d/3d texture through a layered texture node.

----------------------------------------------------------------------

I got the "fresco" look in the render by screening the gradient on top of a fractal through a layered texture. That's the basic setup but of course you could try the other blending modes or just piping the fractal into one of the color inputs for the ramp. The latter gives a little more control on where you want the fractal to end.

Hope this helps and I can upload a scene file for you if you want.

-Angel

PLxKARL
09-11-2006, 04:09 PM
Scene file would be really helpful. Thx.

CGTalk Moderation
09-11-2006, 04:09 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.