Challenge #1: Fruit Bowl - Tutorials & Breakdowns

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  01 January 2006
Challenge #1: Fruit Bowl - Tutorials & Breakdowns

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
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Jeremy Birn
Author, Digital Lighting & Rendering, 3rd Edition

Last edited by jeremybirn : 01 January 2006 at 12:26 AM.
 
  01 January 2006
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.

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

  • 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.


Scene setup:



here the result:
http://forums.cgsociety.org/showpos...81&postcount=93
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Last edited by Samo : 01 January 2006 at 12:18 AM.
 
  01 January 2006
There's not much to breakdown in my shot. But hopefully you guys will get something from it.

Occlusion Pass:



Key:



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

Fill:



RimLight:



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:



Here is a viewport grabof the setup:


Last edited by ACamacho : 01 January 2006 at 12:21 PM.
 
  01 January 2006
Well... I imagine my scene in the controlled situation, like a studio. I started defining my key light with a golden color:



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.



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.



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



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.



The light setup:



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



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

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Yohann da Geb

Last edited by yohann : 01 January 2006 at 02:05 AM.
 
  02 February 2006
Hi Jeremy, I'm quite interested in seeing your fruit bowl breakdown. Thanks in advance.
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  02 February 2006
OK, here we go. The final image:


Here's the master layer (ie. all the lights visible at once) in wireframe:


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:


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:


-jeremy
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Jeremy Birn
Author, Digital Lighting & Rendering, 3rd Edition

Last edited by jeremybirn : 02 February 2006 at 01:26 PM.
 
  02 February 2006
Pass Breakdown

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.

|
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.


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.


rim pass


fog pass


GI pass


occlusion pass


ambient pass


bg layer


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
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Jeremy Birn
Author, Digital Lighting & Rendering, 3rd Edition
 
  02 February 2006
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
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  02 February 2006
Originally Posted by swag: 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


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
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Jeremy Birn
Author, Digital Lighting & Rendering, 3rd Edition
 
  05 May 2006
Originally Posted by ACamacho: Key:






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.
 
  05 May 2006
Jeremy, can I ask you how you got the fog pass and the GI pass?
Thank you.
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Sy.

www.silviapalara.com
 
  05 May 2006
Originally Posted by silvia: 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
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Jeremy Birn
Author, Digital Lighting & Rendering, 3rd Edition
 
  05 May 2006
Sorry, you are right, I missed the GI pass. Thank you for explaining the fog pass, I never heard of it before.
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Sy.

www.silviapalara.com
 
  05 May 2006
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
 
  09 September 2006
Hey,

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
 
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