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| | Synthetic Imaging Combining 3D models with photos, or crafting fully synthetic images using modeling and rendering software | 
01-02-2008, 03:53 PM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | 3D wine glass This is the latest 3D still I made in my exploration with photo-realistic rendering in Maya. It's a straight render with no Photoshop work. | 
01-02-2008, 05:16 PM
| | Senior Member | | Join Date: Jan 2006 Location: chicago
Posts: 703
| | | Re: 3D wine glass looks nice..how does Maya define photo-realistic?..does maya offer any depth of field controls or does that have to be done in photoshop? | 
01-02-2008, 06:18 PM
|  | Moderator | | Join Date: May 2004 Location: Goiânia, Brazil
Posts: 1,536
| | | Re: 3D wine glass The reflections and refractions look very good , but you can see why folks usually use a black matte background for showing off glasswork. The way it is, it's pretty hard to make out the empty glass. Try darkening the tiles (a lot).
Also the close-up camera distorts the shapes and detracts the viewer.
Nice work.
Rô | 
01-02-2008, 09:10 PM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass Quote:
Originally Posted by pixelzombie looks nice..how does Maya define photo-realistic?..does maya offer any depth of field controls or does that have to be done in photoshop? | Maya itself doesn't define realism, really...it's the renderer. Maya native renderer is mediocre; however, it's now a truly complete 3D package ever since it incorporated Mental Ray in version 6.5. Mental Ray's a very powerful renderer that's able to render all things in the psychical world and their properties. Its nodes and attributes are almost overwhelming and certain input values need to be very specific in order to achieve the looks you're after. For instance, I had a tough and frustrating time to get the glass to look the way it looks now just because my refraction index value was only .4 off from the refraction index value of glass in the real world. Its limitation is really the users knowledge. The image is very focus overall, 'cause I used a very simple camera with default setting. Maya does have DOF capability and that's what I'm trying to figure out how it works. It's a slow process...and I'm still working on the lighting setup for the car from my other post. Quote:
The reflections and refractions look very good , but you can see why folks usually use a black matte background for showing off glasswork. The way it is, it's pretty hard to make out the empty glass. Try darkening the tiles (a lot).
Also the close-up camera distorts the shapes and detracts the viewer.
Nice work.
Rô
| I actually used darker tiles for my first render, but I prefer the lighter version somehow. I'll include it here, so you can compare. Good point, I used a 35mm lens for that shot. It looks more proportional at 70mm. I'll post a render when I get that done. | 
01-03-2008, 12:30 AM
| | Member | | Join Date: Jun 2006 Location: Berlin
Posts: 41
| | | Re: 3D wine glass Which lightning setup do you have used? normals spot light or global illumination? | 
01-03-2008, 08:04 AM
|  | Moderator | | Join Date: May 2004 Location: Goiânia, Brazil
Posts: 1,536
| | | Re: 3D wine glass Quote:
Originally Posted by pixel_monkey ...DOF... It's a slow process... | For a one-off image it's a lot quicker to render out a depth map and use that in Photoshop to control a lens blur.
OK, it's postwork - but, to me anyway, postwork is a perfectly valid part of the process.
Rô | 
01-03-2008, 04:36 PM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass Quote:
Originally Posted by Yoolan Which lightning setup do you have used? normals spot light or global illumination? | This scene is illuminated by a single spot light that emits photons, hence the caustics you see on the surface of the tiles. No GI was needed. Quote:
For a one-off image it's a lot quicker to render out a depth map and use that in Photoshop to control a lens blur.
OK, it's postwork - but, to me anyway, postwork is a perfectly valid part of the process.
Rô
| I can just do the DOF in Photoshop with no problem. Since I'm doing this in 3D, I might as well learn how to do it within the program and take advantage of the 3D environment to achieve more accurate result. The rendering part shouldn't take long at all. I was referring to the "trying to figure out how it works" part being a slow process, especially when doing it accurately. | 
01-07-2008, 02:04 AM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass Well, rendering DOF with Mental Ray in Maya proved to be difficult to control and I just couldn't get any decent result out of it. What I did here was rendered out a Z-depth map and used it in post for the DOF. I put the Z-depth map in the Lens Blur filter in Photoshop and the result turned out a lot better than what I got in 3D. | 
01-07-2008, 08:08 AM
|  | Moderator | | Join Date: May 2004 Location: Goiânia, Brazil
Posts: 1,536
| | | Re: 3D wine glass The only thing you have to watch out for when doing DOF this way is dealing correctly with transparencies.
As you can see on the depth map, the left wine-glass is all white, but what we actually see at the top of the glass is the background and not the glass.
Mind you, it's the sort of thing only a nitpicker would worry about  , and I only saw the sharp background there because I was looking for it!
Rô | 
01-07-2008, 12:49 PM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass You do have an eye for this sort of stuff. It does look like an additional alpha channel on top of the transparent objects is needed for this kind of render. Other than that, the depth map works great on shaded objects and I can actually able to control the amount of DOF I want in real time. | 
01-12-2008, 10:26 PM
|  | Senior Member Patron | | Join Date: Feb 2007 Location: GrandPrairie.TX
Posts: 409
| | | Re: 3D wine glass Your right about seeing only background in the top of the glass, Ro. That's something that I have noticed that you get when you render an object like this. I usually fix these problems in Photoshop.
Pixel monkey, did you use the lathe modifier to create the glass? That's how I usually do it. | 
01-13-2008, 02:00 AM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass Dave, I used a reference image of the glass and traced the profile with a curve, then I revolved the curve 360 degree in the Y direction. All necessary adjustments were made via the control points on the curve. | 
01-13-2008, 06:25 AM
|  | Moderator | | Join Date: May 2004 Location: Goiânia, Brazil
Posts: 1,536
| | | Re: 3D wine glass Quote:
Originally Posted by pixel_monkey ...I used a reference image of the glass and traced the profile with a curve .... | Just another nit-pick.
In my ..er.. limited experience with wine glasses the bottom of the glass wouldn't be so flat.
Not that this in any way detracts from your render - but you would probably get a few more interesting reflections / refractions in the base.
Rô | 
01-13-2008, 08:49 AM
|  | Senior Member Patron | | Join Date: Feb 2007 Location: GrandPrairie.TX
Posts: 409
| | | Re: 3D wine glass Yep, that's how I would do it, although I use 3DS. To rotate the spline in 3DS, you would use the lathe modifier. If you are interested, you can look at some of my other work here: http://www.davesdfr.com. Look for the 3D section in the gallery.
I'm afraid that I'm not familiar with Maya, although I understand that they are similar.
You might want to check out this site. http://www.3dbuzz.com/vbforum/sv_home.php
Some really cool stuff there.
I thought that I would try a version of this. This is 3D Studio, no Photoshop.
Last edited by Dave.Cox : 01-13-2008 at 11:45 AM.
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01-14-2008, 01:32 PM
|  | Senior Member | | Join Date: Jun 2007 Location: Los Angeles, CA
Posts: 206
| | | Re: 3D wine glass Rô,
I started off with a thicker base, but I didn't like the way it reflected and refracted with the surface so I thinned it down. I might like the thicker base better if I put the glass in a photographic environment with an actual environmental map for the glass to reflect upon. That's what I'm working on at the moment, but with flowing liquid this time.
Dave,
There's no lathe modifier in Maya. It has something called the shape deformer, and a whole bunch of other deformers and modifiers, but none of them is necessary for a simple glass primitive. I find that I get more control over the shape by pulling vertices on the curve.
I used to frequent 3dbuzz a lot more often than I do here. I like it back in the days when they gave you generous space to upload your demo reel in your user profile and when you sent them a blank CD-R with a pre-paid envelop, they sent you back some good tutorial vids...those were the days. Like highend3d and cgtalk, I haven't been there in a while. I'm just fortunate that I have quite a few friends working all over LA from gaming to CG movies. They constantly provide me with some great learning materials and keep me in touch with 3D.
One of the biggest challenges that I encountered with rendering the glass and liquid was finding the correct refraction index value for each of them and having them interact with one another to get them to look the way they look now. I'm not sure how the material shaders work in 3dMax, I used the value of 1.5 for the glass and 1.33 for the liquid. They are all based on real world values. I also used an extra material that interacts with the glass and liquid right at where they meet. In the real world, you won't be able to see the thickness of the glass at all when it's filled with liquid. Check out The Gnomon Workshop or Digital Tutors, they have some great rendering DVDs...at least for Maya. |
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