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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Nov 21 6:06 am)



Subject: Emulating "view cameras"?


ockham ( ) posted Thu, 16 July 2009 at 1:31 PM · edited Fri, 22 November 2024 at 6:13 AM

I noticed an interesting discussion of "view cameras", with separately adjustable
front and back planes, on the Shorpy website.

http://www.shorpy.com/node/6503

I know nothing about cameras, but a "view camera" would seem to be superior
for large scenes, enabling us to straighten out perspective distortions.

Is there any way to emulate this degree of control in Poser?

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FrankT ( ) posted Thu, 16 July 2009 at 1:49 PM

Various bits of software allow you to emulate a shift lens, but I've never come across anything that tried to emulate a full blown Sinar F1 (the one I have for e.g.)  The movements on a view camera are very useful but are mostly to do with changing the plane of focus to pretty much anywhere you want it to be.  They are great fun to play with but I dunno if Poser cameras could do that kind of thing

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ockham ( ) posted Thu, 16 July 2009 at 1:54 PM

Okay, thanks.  As mentioned, this is a completely naive question.... it just looked
like a useful optical technique, and Poser's cameras are not well-suited for
large scenes.

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lesbentley ( ) posted Fri, 17 July 2009 at 6:07 AM · edited Fri, 17 July 2009 at 6:09 AM

I doubt that a it is practicable to emulate a view camera for a single pass render, and certainly not in a wysiwyg preview mode. Perhaps something could be done with reflection or refraction, but I have no idea how.

You could render the scene, then use the render as a material on square primitive. The square could then be tilted at any angle, and I think this would emulate the perspective corrections achievable in a view camera, but I suspect the image quality would suffer too much.

I have never done any really large scenes, and am wondering why you say that "Poser's cameras are not well-suited for large scenes"?


EnglishBob ( ) posted Fri, 17 July 2009 at 9:35 AM

A view camera is handy for a real life ("meat space") photographer, since it allows distortion-free photos to be taken from the real life photographer's normal camera position, namely five to six feet above the ground. Virtual photographers have no such restrictions. Our cameras can be mounted on top of virtual fifty-foot poles if necessary, to get the same result. View cameras are unnecessary in 3D graphics. :)

For correcting an already distorted image, Les'  technique will work, at least at a quality level which is adequate for backgrounds. I haven't tried it for anything close-up, but given the likely reason for the distortion occurring in the first place, that probably wouldn't be a problem.


ockham ( ) posted Fri, 17 July 2009 at 10:19 AM · edited Fri, 17 July 2009 at 10:20 AM

Good point about virtual freedom.  Still, my purpose isn't to get the whole building
in but to get a ground-level (human-eye) picture that lets the building look closer
to orthogonal.

Yeah, I'd thought about the tilted square, but it seems like you'd have varying resolution,
and a square never looks quite the same as a "real" 3d structure.

@Les: the problem with Poser cameras in big scenes isn't an optical one, it's just
that the trackball controls don't move fast enough.  It can sometimes take 10 or
12 big 'sweeps' of the mouse to get from one house to the next.  Same with
parameter dials.  If Poser's parameter dials worked like Daz Studio's sliders,
with accelerating motion as you continue to slide, this problem could be solved.

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maclean ( ) posted Fri, 17 July 2009 at 11:10 AM · edited Fri, 17 July 2009 at 11:21 AM

I also have serious problems with Poser's cameras in large scenes (ie. almost everything I build). For years now, I've been hoping for a Frame command, similar to Studio's, where I can select any object or body part and immediately frame it.

Poser's cameras were designed for a human figure in the center of the window, and since Version 1, they've never really changed much. They need to be updated to reflect the fact that people make much bigger and more complex scenes than 15 years ago. Ever tried to move through one of Stonemason's scenes (like Streets of Asia) in Poser?

One of the biggest problems, apart from trying to zoom in on small details, is that the Poser cams are locked on the 0 0 0 coordinates (other than the Dolly cam), so once you do get close to something way off-center, you can't rotate around it properly because the camera always wants to point at the center of the universe. In DS, you have Frame and Aim At, both of which make the selected object(s) the new center, and the camera orbits round that, not 0 0 0.

As a scene builder, I find that all the things that drive me insane with Poser, go largely unnoticed by the majority of users and the Poser owners. (I once ranted to eF about not being able to delete a parent prop and all it's children with one click and was told "they didn't think it was an issue"). I know I'm in a minority because Poser evidently isn't meant to do much more than pose a figure and throw clothes on (as far as the owners are concerned), so I mainly keep quiet about it and use Daz Studio as my primary app instead. But I can't avoid using Poser to test products and that's when the screaming and cursing starts.

I didn't upgrade to Poser 7, and I'll only upgrade to P8 if it has some dramatic improvements. But they day they add a Frame function, I'll throw my wallet at them.

Sorry for the rant but it's not often this subject is brought up and it's one I feel very strongly about.

mac


markschum ( ) posted Fri, 17 July 2009 at 11:16 AM

err, Ockham , but well, have you considered writing a camera control script ? 


EnglishBob ( ) posted Fri, 17 July 2009 at 11:22 AM

Attached Link: http://ockhamsbungalow.com/Python/

SnapToCam and a host of other useful camera scripts at the link. ;-) 


bagginsbill ( ) posted Fri, 17 July 2009 at 12:23 PM · edited Fri, 17 July 2009 at 12:24 PM

To avoid distortion of tall buildings, do not pitch your camera up. If you pitch up to bring the top of the building into view, then you make the top farther from your focal plane than the bottom, and it becomes smaller.

If your focal plane remains vertical (camera pointed at horizon) then straight vertical things like buildings remain straight.

The tilt-shift lenses and/or view cameras in real life are doing the same. You keep the camera pointed level, not up. Then you move the projected image. Basically this is real-time panning or cropping.

If you think correctly about the projection plane, you will realize that it is infinite. Whether you have film or a digital sensor, either way you are capturing a rectangle from that infinite plane of projection. By panning or cropping that image, you can choose what part to see.

Therefore, you can choose to crop the part between the base of the building and the top of it. This is a little harder to do with Poser, but not impossible.

With your camera level, zoom out (decrease focal length) until everything you want is visible. This will bring in the high points, as well as a huge bit of local ground you're probably not interested in.

Now do an area render, rendering only the part you want. If it is small, change your output size to something larger, perhaps considerably larger. Render the area you want (that's the "view cam" part) and then crop it.

Problem solved. No more tilted buildings.


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lesbentley ( ) posted Fri, 17 July 2009 at 12:27 PM

file_434840.jpg

Without a view camera the perspective is a function of the point of view. Buildings (or anything) will look straighter (less tapered) if you move the camera further away. Then you will need to increase the focal length to compensate for the more distant camera.

In both images above the camera is 0.365 PU above the ground. In the the top image DollyZ is -0.210000 PU, and the focal length is 25mm. In the bottom image DollyZ is 6.366 PU, and the focal length 200mm.


lesbentley ( ) posted Fri, 17 July 2009 at 1:01 PM

Quote - One of the biggest problems, apart from trying to zoom in on small details, is that the Poser cams are locked on the 0 0 0 coordinates (other than the Dolly cam), so once you do get close to something way off-center, you can't rotate around it properly because the camera always wants to point at the center of the universe.

To get the Main or Aux camera to orbit a prop, rather than the 0 0 0  point, zero its x and y translations, zero all its rotations, Memorize it (Alt+Ctrl+H), parent it to the prop, then use Restore Camera (Shift+Ctrl+H). The camera will now orbit the origin of the prop. All the zeroing is not strictly necessary, but it stops the camera getting lost in space.


lesbentley ( ) posted Fri, 17 July 2009 at 1:27 PM · edited Fri, 17 July 2009 at 1:29 PM

file_434845.TXT

Attached above is the text of a pp2 that contains a camera. The camera has 3 extra dials;

Fast dollyZ
Fast dollyY
Fast dollyX

These should help you move around the scene faster. It's a P6 camera, but will probably work in later or earlier versions. I haven't had time to test it properly, so there may be bugs. For instance I don't know if it will work OK with depth of filed, or motion blur. Use at your own risk.

Because of a bug in P6 (and perhaps later versions), the new camera will not show up in the Camera Controls, or in the Display > Camera View menu. To select the view  from the new "FastDolly" camera, you will need to right click in the document window, and select the view from there.


lesbentley ( ) posted Fri, 17 July 2009 at 1:53 PM · edited Fri, 17 July 2009 at 1:56 PM

P.S. You will need to control the "FastDolly" camera from its parameters pallet. It won't work properly from the Camera Controls. The track ball should work OK , but not the others.


lesbentley ( ) posted Fri, 17 July 2009 at 2:16 PM

file_434849.TXT

OK, here is a new version that won't screw up when you use the Camera Controls.


maclean ( ) posted Fri, 17 July 2009 at 3:15 PM

Les,

I appreciate the camera files and I'll certainly try them, but it doesn't change the issues with Poser.

You see, the problem is I sell content - large scenes - and anyone who uses them has the same issues. That's why I'd like to see these things resolved in Poser itself. I've already done things like include Dolly Cam props in my packs, but again, it's not a real solution.

"You will need to control the "FastDolly" camera from its parameters pallet. It won't work properly from the Camera Controls. The track ball should work OK , but not the others"

This is the sort of thing I come against in Poser too. I use all sorts of hacks, but it's a battle. For example, when I parent lights to a figure (giving them unique names, etc), they don't appear in some menus. Alt geom dials can't have geom names - just 0 - 2 or whatever. Saving figures with cameras and lights is a major hassle. (.pz3s aren't an option, since DAZ won't accept them because they change the users UI - and stripping that info out is a pain anyway). Lots of little things that make my workflow difficult, and most of which aren't even an issue in Daz Studio.

What I'm saying is Poser is still aimed at the 'one figure in the center of the viewport' mentality and anything else outside that isn't considered worth paying attention too by the Dev Team. That's maybe a bit of an exaggeration, but sometimes it seems like they don't ever think that people use content other than humans, and it irks me.

Thanks anyway, les.

cheers

mac


lesbentley ( ) posted Fri, 17 July 2009 at 5:30 PM

Quote - What I'm saying is Poser is still aimed at the 'one figure in the center of the viewport' mentality and anything else outside that isn't considered worth paying attention too by the Dev Team.

I agree with much of what you say, and could easily add a few gripes of my own, but Poser development is out of our hands, so unfortunately we just have to muddle through with what we are given.


VK ( ) posted Sat, 18 July 2009 at 6:19 PM

file_434910.jpg

 

Quote - Problem solved. No more tilted buildings.

 

The Rise/Fall option of a CG camera is still useful. Although you can increase the camera distance of a CG camera, the cropped and resampled image will look different (see picture). Why? Modifying the camera distance also changes the perspective distortion of the object --unless you also modify the focal length, which in turn leads to a different field of view.

 

The Rise View option will pan the view and at the same time preserve the field of view and the perspective distortion of a real perspective correction lens or a view camera.


VK ( ) posted Sat, 18 July 2009 at 6:55 PM

Attached Link: camorbit.pz3

file_434912.jpg

 

There was another hack for the orbit center problem: 

 

Just add a second set of "translate" channels at the end of the channels list of main camera (and aux camera). Be sure to change the channel names and dial names of the new channels. Now you can use the "Dolly" dials for standard pan, or the new dials for framing pan. The new channels will pan the view, too, but the camera will always orbit the center of the image frame (unless you also set the Dolly dials).

 

This used to work in Poser 4. The attached zip contains an old .pz3 demonstrating the new camera dials. I don't know if it works in newer versions, I stopped using Poser at version 4.

 

To use the new camera channels in new documents, I included them in the "preferredState" and in the "camerasAndLights" script, IIRC.

 


maclean ( ) posted Sun, 19 July 2009 at 4:30 AM

Thanks, VK. I'll try that too.

Btw, long time, no see. I still give people the link to your ERC tute. LOL.

mac


VK ( ) posted Sun, 19 July 2009 at 6:36 AM

Hi mac,

Yes, hope you're fine. Are you still in the Alps?


wolf359 ( ) posted Sun, 19 July 2009 at 7:04 AM · edited Sun, 19 July 2009 at 7:06 AM

Quote - Les,

What I'm saying is Poser is still aimed at the 'one figure in the center of the viewport' mentality and anything else outside that isn't considered worth paying attention too by the Dev Team. That's maybe a bit of an exaggeration, but sometimes it seems like they don't ever think that people use content other than humans, and it irks me.

mac

I agree with your asessment which is why I started looking for ways  to get that one figure OUT  the center of the  poser viewport and into another programs to render since the  bygone days
of "Fractal Designs" Poser 2 and "Metacreations" Bryce 2.

Thankfully we have many such alternative solutions available today.

Cheers



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bagginsbill ( ) posted Sun, 19 July 2009 at 9:49 AM

Quote -   > Quote - Problem solved. No more tilted buildings.

 

The Rise/Fall option of a CG camera is still useful. Although you can increase the camera distance of a CG camera, the cropped and resampled image will look different (see picture). Why? Modifying the camera distance also changes the perspective distortion of the object --unless you also modify the focal length, which in turn leads to a different field of view.

 

The Rise View option will pan the view and at the same time preserve the field of view and the perspective distortion of a real perspective correction lens or a view camera.

Hi VK. You quoted me and seemed to be phrasing your post as a contradiction to what I said. Just to be clear, I did not suggest moving the camera, somebody else did, and I agree that is not necessary nor desirable. That is why I never mentioned it.

The OP asked how to do this in Poser, and I answered how to do it in Poser. The only way in Poser to render off-center is to do an area render.

The "Rise View" option you speak of is not in Poser, right? Or is that a plugin you have for Poser?


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maclean ( ) posted Sun, 19 July 2009 at 3:47 PM

Hi VK,

Yep. I'm still in the Alps. Went for a 3-day hike to a refuge at 3,000m last week.

As Ronald MacDonald would say "I'm still lovin' it!" - lol

mac


VK ( ) posted Sun, 19 July 2009 at 4:12 PM

Hi bagginsbill,

I quoted you for agreement --cropping indeed solves the problem of tilted buildings. The following just points out that the result of a rise view option looks different, and that this option is useful for a CG camera if you need exactly the look of a real view camera. The renders are from ElectricImage.

 


VK ( ) posted Sun, 19 July 2009 at 4:16 PM

Quote - Hi VK,

Yep. I'm still in the Alps. Went for a 3-day hike to a refuge at 3,000m last week.

As Ronald MacDonald would say "I'm still lovin' it!" - lol

mac

Hi mac,

Sounds great. Although I prefer to see these rocks from afar. lol

 


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