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-   -   Reality Sets for Chroma Key (https://www.dvinfo.net/forum/360-panoramic-spherical-ar-vr/489012-reality-sets-chroma-key.html)

Kevin Lewis December 16th, 2010 01:54 PM

Reality Sets for Chroma Key
 
Does anyone know where I can purchase reality sets for chroma-keying. I see lots of virtual studios and backgrounds but i'm looking for real sets such as the inside of of buidlings, offices and other real life backgrounds.

Jonathan Jones December 17th, 2010 02:23 AM

I agree, many virtual sets I've seen available look overly cartoonish, and what I suppose must be intentionally fake looking, categorizing them as extremely limited utility for the purposes of "realism" in chroma-key environments. Although I have also seen some sites where they specifically distinguish their "real" virtual sets from their "virtual" virtual sets, with the real ones including actual location footage, and the virtual ones appearing in a fashion that many folks evidently characterize as "virtual reality" in that it represents recognizable content, but would certainly never be mistaken for the real thing. (basically watercolor appearances with the saturation turned up way too high)

Certainly there are a number of resources that provide really awesome looking virtual sets that even include very nice motion interaction with zooms and pans, but I've yet to see any that also didn't look rather cartoonish. I've seen such things used in a lot of production, and while many of them are rather "cool" looking, I find that I'm often distracted by the "cheese" factor - but maybe that's just me.

I haven't thought about it much in terms of looking for resources that provided "realistic" virtual sets, as I have most often just "built" mine using Photoshop and a number of composited stock elements to create a realistic setting. In a few instances, I've just been able to physically go on location and shoot some bits for future use, but this is not often practical or possible.

So, upon your query, I used Google. A lot of things came up and some clicking and exploring is in order.

Here is one of the first places that popped up. I have never used their stuff, but I just searched through it, and found a number or pieces that I could probably put to use at some point.

Reality Sets. Beyond Virtual Sets For Chromakey Green Video Productions.


I'd certainly be curious as to what other types of input may follow in this thread.

-Jon

Kevin Lewis December 17th, 2010 09:06 AM

Johnathan thanks for your input. Its amazing how few sites there seem to be that offer this type of background. Hopefully some other folks may also be able to give suggestions.

Bill Mecca December 17th, 2010 09:15 AM

If you don't need motion, iStockPhoto, or stock.xchng - the leading free stock photography site will work. I recently used a living room shot, threw a bit of gaussian blur on it for DOF and it worked quite well.

Kevin Lewis December 17th, 2010 09:31 AM

Bill, does a photo give the same type of realistic feel that video does?

Jonathan Jones December 17th, 2010 11:18 AM

Quote:

Originally Posted by Kevin Lewis (Post 1599482)
Bill, does a photo give the same type of realistic feel that video does?

I'll chime in here.

It really depends upon the photo itself, and how you shoot your subject to integrate with it. Some factors might include:

- Are there elements within the still shot that one would normally expect to be moving (traffic, leaves rustling through trees outside a window, starlight twinkling, clouds, etc.)?

- Is the angle from which the still shot was taken appear as a natural "fit" with the angle from which the subject is being shot?

- Can you light your subject in a manner appropriate to the use of light dynamics in the still shot?

Other factors to consider is the attention to resolution matching between subject and background, as well as manipulating depth-of-field for the perception of distance between the subject and elements in the still shot, and perhaps the way that the shadow from your subject might interact with surfaces in your background. I will frequently use a still shot for my backgrounds, but then add some appropriate object elements with alpha channels that I can position as needed, apply DOF and distance factors to help sell the perception of the subject interacting with the perceived environment.

-Jon

Jacques Mersereau May 1st, 2016 02:09 PM

Re: Reality Sets for Chroma Key
 
My two nickels,

I think there is going to be a good market for VR and chroma key sets in the years ahead.
There is need for something akin to quicktime, a format that enables the camera/viewer to enter into
a 'background environment" and move around inside and then somehow import that into editing software to as to deliver an edited version/program.

What will be needed is the ability track/move around the space as if we were there in person - through our eyes.

Check out this video to see the kind of environment I am thinking about -
a 'place' where you can jump from 'light probe' to light probe like Google street view.


Bruce Dempsey May 2nd, 2016 05:53 AM

Re: Reality Sets for Chroma Key
 
I am building a 48 still camera rig which circles a subject to produce the subject as a 3d obj.
Reading this thread makes me wonder whether a 3d environment could be created for chroma key purposes by positioning all the cameras facing outwards (in a room such as you describe) at the point your actor will be positioned and stitching the room from the photos. Hmm

Seth Bloombaum May 3rd, 2016 10:25 AM

Re: Reality Sets for Chroma Key
 
Quote:

Originally Posted by Bruce Dempsey (Post 1913748)
I am building a 48 still camera rig which circles a subject to produce the subject as a 3d obj.
Reading this thread makes me wonder whether a 3d environment could be created for chroma key purposes by positioning all the cameras facing outwards (in a room such as you describe) at the point your actor will be positioned and stitching the room from the photos. Hmm

A common 360x180-degree still panorama format is an equirectangular projection, which many 3d programs can readily convert to a "VR" viewport, including niceties like pinning and tracking.

To my understanding, it's being done in some productions to get to photorealism, along with photogrammetry to derive true 3d from still photographs.

There are many approaches to shooting still panos, along a couple of important variables: How much time do you have to shoot (is the subject in-motion?); and, how close are subjects to the camera or camera array, which includes how much parallax error is built into the array.

A single still camera, rotated on its no-parallax-point, aka. nodal point, can produce images of any resolution which are stitchable with no parallax errors. An array of 6 or 7 gopro cameras has a limitation of how close subjects can be before showing parallax errors in the stitch, but, can capture a still instantaneously or even video. Lots of interesting cameras coming out that make 360x almost 180 quite straight forward for single exposures or video.

Here is a demonstration of people green-screen composited into a 360x180 panoramic environment. This was a demo project, so I don't have much more than this pano to show. Click and drag to pan and tilt.

There's quite a lot of image geometry correction that goes into this composite, first to create the pano out of the 17 or so images that were shot, then to... well, there are a lot of steps! If this project had gone forward we hoped to get to video. With this approach, one pano represents one camera position, but, with photogrammetry, multiple panos could be converted to a single 3d model...


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