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Cgi retouching courses or schools

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  #1  
Old 01-24-2014, 06:00 AM
Isedo Isedo is offline
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Cgi retouching courses or schools

Hi all, I work a lot of years in the digital imaging industry but I always want to improve my skills. I'm totally self made so now I have some free time in the coming months and I'd like to take some academic courses about GCI mixed with retouching. In special way the car advertising field.

Is out there some very very good school or courses, also online about this subject? As told before I'm able to do almost everything with Photoshop and Im not bad with 3D but still, I'd like to walk again the learning path and discover some maybe missing points or just fix something trough a good course which really explains how to approach this kind of images:

http://www.plgr.cz/images/136/388-pl...ceback_001.jpg

I'm quite sure I know how to do this image but if you know what i mean, I just want to enjoy the learning thing from someone who does this for real without any "test and maybe".

Thanks to all who can help
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  #2  
Old 01-26-2014, 06:47 AM
klev klev is offline
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Re: Cgi retouching courses or schools

Dealing with rendered images isn't that different. Given the clipping on that jpeg, I'm guessing you saved it from something that the render was initially output to some linear float format with an extended stop range. Typically the person who created the render would render out either alphas or some kind of matte per color to help in separating things. It can be done per object, per material, whatever. You should look for material on Nuke and linear workflow. Some of it applies to photoshop, although photoshop's tools are severely limited at 32 bpc unless CC changed that. In either case you would have to resolve any clipping issues before you can deal with it at 16 bits per channel in photoshop.

Apart from that it's just an issue of car details. This render does seem to be a little bit off, but white paint is difficult to render without custom shaders.
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  #3  
Old 01-26-2014, 08:34 AM
Isedo Isedo is offline
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Re: Cgi retouching courses or schools

Thanks so much for your answer but in this post i'd real like to know if there is any good core or school that is focused on this. Do you know any?
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  #4  
Old 01-26-2014, 11:17 AM
skoobey skoobey is offline
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Re: Cgi retouching courses or schools

Well there are really a couple parts of materialization you should work on.

First it's the mapping has be as exact as possible to allow for smooth transitions. In that case you're do one who is modifying displacement maps, and their properties in photoshop and checking that they fit the 3d model well.

Then there is the other side of work, which can be done in Nuke as an example of 3d motion pictures where it's actually more efficient to blend little imperfections after the whole thing has been rendered, then to make it perfect form the get go (making areas smooth on video, making textures blend instead of looking choppy etc).
And, of course there is the retouching itself, as the rendering works in realm of physics and won't produce impossible colors, shadow, lack of shadows, contrast, lack of contrast etc etc... this is where you actually retouch, and this is done after the video has been edited, or when all of the images have been rendered out.

As for still images... it involves a lot of compositing, especially on cars, and yes, good 3d artists know to provide you with masks for each panel. You basically merge best lighting situations to a car that is at the same angle for all of them, and often you add shadows to the given surface the car is supposed to be situated in, as well as puting additional reflections of the surroundings on the car, and placing them in a flattering way.

Then there is the merging of interior and exterior renderings, and sometimes merging a shot of a person driving with rendered exterior, or rendered interior...

Basically just like any other product retouching except the occasional part where you have to correct for the 3d imperfections.

Photoshop still sucks as a serious 3d software.
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  #5  
Old 01-26-2014, 12:35 PM
Isedo Isedo is offline
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Re: Cgi retouching courses or schools

Hi Skoobey,

Thanks for the answer. What you mean with smooth transitions? Why we are talking about displacement maps? I mean, for what? Are u referring to the reflections on the car?

That can be done directly in the 3D render using some HDRi Map or i'm not getting your point maybe. Can u explain?

Now NUke is a compositing software but I'm pretty sure, since this image is a still image, it's all done in Photoshop using Multi pass from the source 3D software.
We are not talking about video but still images here. ;-)

I know how this images are done and I can get very close to that look by my self. What I'm asking is to know if there is any specific school or course which is focused on this. Why? Becouse I just like to go further in my skills and just see if I'm missing or can improve something.

Bytheway thanks for your post and sharing your knowledge.
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  #6  
Old 01-26-2014, 12:49 PM
skoobey skoobey is offline
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Re: Cgi retouching courses or schools

Often, especially in motion rendering you get sudden edges where you don't want them, due to the plains not fitting 100% right with movement, and it's less time consuming to fix it in post, rather than fix the elements, as you fix them, and it causes problems in the next movement, so you just fix it in post.

Everything in 3d needs a displacement map in order to be rendered/materialized.

Reflections are in fact a reflection of the global environment and light sources set for the render. Both of which can be turned off selectively in the render process. This stands for both still and video (which is also a bunch of stills).

Yes, but you make maps and textures and everything for each material, not just a global HDRI that is being reflected on shiny surfaces of the rendered objects.

When you have something directional such as wood, it is a bitmap that is imported into a 3D program, and you need to match it across curved panels. Get what I'm saying?

The best way is to land a job at an agency. If you admire someone's work, just go ahead and ask them.
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  #7  
Old 01-26-2014, 01:34 PM
Isedo Isedo is offline
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Re: Cgi retouching courses or schools

Yep, getting that and I agree.
Agree also with the agency thing but I'm not that young now to do an internship. I work as freelance so now with some spare time in next months I'd like to fix some details maybe taking some course but I'm pretty sure there not one around about what I'm looking for.

It's a matter of time, hard work and practice.
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  #8  
Old 01-26-2014, 02:45 PM
klev klev is offline
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Re: Cgi retouching courses or schools

Quote:
Originally Posted by Isedo View Post
Thanks so much for your answer but in this post i'd real like to know if there is any good core or school that is focused on this. Do you know any?
Schools typically teach principles. This is not a principle. It is a specialized subject that applies to a small subset of people within a given field. Are you comfortable working on cars? They would be a difficult subject for me. There's nothing inherently different whether it's from a render or photo though as long as you have strong foundational skills. You'll still balancing densities and trying to show off specific details.

Quote:
Originally Posted by skoobey View Post
Everything in 3d needs a displacement map in order to be rendered/materialized.
Are you sure you're using the correct term there? A displacement map in that sense means something that scales vertices along their normals after subdivision. It does not have to be explicitly mapped. I don't think he would even benefit from doing that on a vehicle due to how much its a smooth surface. I wouldn't consider it unless you were doing some close up work. If you were doing an interior it could make significantly more sense with some of the fabrics and things. Texturing in 3d is really its own topic though. While I guarantee it wouldn't focus solely on vehicles, you can find courses in that. I don't know whether it would really help the OP. As you suggested the best way to learn a set of good working practices would be to work in a shop that regularly handles this sort of thing.


Quote:
Originally Posted by skoobey View Post
Then there is the other side of work, which can be done in Nuke as an example of 3d motion pictures where it's actually more efficient to blend little imperfections after the whole thing has been rendered, then to make it perfect form the get go (making areas smooth on video, making textures blend instead of looking choppy etc).
And, of course there is the retouching itself, as the rendering works in realm of physics and won't produce impossible colors, shadow, lack of shadows, contrast, lack of contrast etc etc... this is where you actually retouch, and this is done after the video has been edited, or when all of the images have been rendered out.
You have a distorted view of how renderers work sir. I used Nuke for reference because it can properly detail with compositing linear passes, although it's possible to just work with a beauty pass and a set of alphas and mattes, none of which are that difficult to tack on. Edit: I also used it for reference because searching for material on Nuke might turn up something more useful that could be leveraged in photoshop, in spite of the mismatched workflows.

These are things that are typically supported out of the box. The other stuff is more an issue of lighting. When it comes to compositing a vehicle to an outdoor environment, a latlong hdri would be used for realistic reflections. You don't have to set it as an environment map. That is something entirely different. An environment map is just a final sample. If raytraced, it would sample once from the environment map if a given ray doesn't trace back to a specific light source within its set depth limit. I mention raytraced because vray and mental ray are common for this sort of thing. In this case it's more likely that the latlong map is used for irradiance cached global illumination. That is not a completely accurate method. You could get closer by using a rebuilt scene and mapped hdri textures, but it's not practical outdoors. The issue of shadows is that it's difficult to get those deep shadows in such a system without using practically all direct light. It's a detail of the system, not due to the laws of physics.
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  #9  
Old 01-26-2014, 03:54 PM
skoobey skoobey is offline
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Re: Cgi retouching courses or schools

Perhaps I wasn't precise enough what is used when it comes to the interior, which uses a lot of textures, as it needs to, from plastics, leathers, fabrics, stitching, wood, metals, inscriptions... and the outside of the car is mostly smooth with a couple of metals here and there, and it is mostly chrome/textureless.

We used Nuke as a post production tool, and everything was modeled in maya.

From the couple of car's that I've put together, I can say, that artists render a car with and without reflections, with some of them on/off etc. It's basically compositing, just like any other photography of a product.

That Skoda posted in the example has at least been rendered as we see it, and from bellow to give that reflection. Wing and bumper are Probably separate render as well. And wheels are pretty much always done separately. I don't know why do they alway send them separately? Anyone has an answer to that?
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  #10  
Old 01-26-2014, 04:23 PM
klev klev is offline
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Re: Cgi retouching courses or schools

Quote:
Originally Posted by skoobey View Post

We used Nuke as a post production tool, and everything was modeled in maya.

From the couple of car's that I've put together, I can say, that artists render a car with and without reflections, with some of them on/off etc. It's basically compositing, just like any other photography of a product.
Does that mean you have a new job? Now I want to hear about that. I didn't go into with and without reflections or anything of that sort, because while it may be quite useful, you have to merge a lot of that in photoshop before going on anyway. In nuke you would just set a reflections pass to additive blending. In photoshop that won't work well unless you're in 32 bit mode, as the others will not apply it correctly. That's kind of why I veered away from talking about that. It can also be confusing to some people that it's called reflection, as a diffuse pass still represents reflected light. I get the point of what you're suggesting, although depending on what it is, they could probably accomplish that via light linking. It shouldn't always be necessary to make multiple renders. Also don't mistake multiple EXR files for multiple renders rather than multiple passes .


Quote:
Originally Posted by skoobey View Post
That Skoda posted in the example has at least been rendered as we see it, and from bellow to give that reflection. Wing and bumper are Probably separate render as well. And wheels are pretty much always done separately. I don't know why do they alway send them separately? Anyone has an answer to that?
The only reason I can think of here to do the wheels separately in that would be to light them separately, but again you could just use light linking unless for some reason it required them to completely hide the car body.
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