Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] Feature Requests => [C4D] Resolved Feature Requests => Topic started by: ozwald on 2017-06-20, 17:39:01

Title: Perspective Correction
Post by: ozwald on 2017-06-20, 17:39:01
Hello everyone, it would be nice to include in the camera tag,
  Perspective correction

Thanks
Title: Re: Perspective Correction
Post by: houska on 2017-06-21, 12:50:40
Hi and thanks for the suggestion!

3DSMax version has no problems with this because it's in the standard Max camera. We will have to implement it ourselves for Cinema4D, but it's a good suggestion. I'll move this thread to suggestion section on the forums
Title: Re: Perspective Correction
Post by: maru on 2017-06-21, 16:22:56
3DSMax version has no problems with this because it's in the standard Max camera
Actually it's the physical Max camera. ;)
There are also plans for a dedicated Corona Camera object. At least for the Max version, not sure if it would be needed in C4D.
Title: Re: Perspective Correction
Post by: Mor4us on 2017-06-23, 22:52:46
You can do really good perspective correction with the native c4d camera object already, I'd be really interested what would be needed over this
Title: Re: Perspective Correction
Post by: burnin on 2017-06-24, 00:10:37
:) maybe i misunderstand

cinema's Camera Object (Object Properties: F.Length, SensorSize...) (http://c4d.cn/help/c4dcn/cn/html/OCAMERA-ID_OBJECTPROPERTIES.html), camera calibration (https://www.cineversity.com/vidplaytut/new_in_cinema_4d_r14_camera_calibrator/) & lens distortion (https://vimeo.com/135274492) tools are not enough? Doesn't work with Corona?

any example?
Title: Re: Perspective Correction
Post by: Rhodesy on 2017-06-26, 11:11:07
Yes or just using film offset for shift lens effect.
Title: Re: Perspective Correction
Post by: houska on 2017-06-26, 11:23:35
You can do really good perspective correction with the native c4d camera object already, I'd be really interested what would be needed over this

:) maybe i misunderstand

cinema's Camera Object (Object Properties: F.Length, SensorSize...) (http://c4d.cn/help/c4dcn/cn/html/OCAMERA-ID_OBJECTPROPERTIES.html), camera calibration (https://www.cineversity.com/vidplaytut/new_in_cinema_4d_r14_camera_calibrator/) & lens distortion (https://vimeo.com/135274492) tools are not enough? Doesn't work with Corona?

any example?

If I understood the OP correctly, he meant correction of verticals in the image, which is impossible to do with a normal perspective camera. But some Googling seems to find an already existing feature in C4D:

https://www.c4dcafe.com/ipb/forums/topic/29142-camera-object-to-maintain-parallel-vertical-lines/

That said, I didn't manage to find the expression they were talking about. Anyway, it would be nice to have this in a more convenient place, so it makes sense to implement it in Corona
Title: Re: Perspective Correction
Post by: Rhodesy on 2017-06-26, 14:39:11
You can achieve the same effect by using the film offset Y option in the camera object so long as you keep the camera perfectly horizontal and vertical. Then just use the Y % spinner to move the view up or down and the lines will keep vertical. No need for a plugin/script.
Title: Re: Perspective Correction
Post by: burnin on 2017-06-26, 17:27:25
Yes, tilt is in the Camera Object... i get confused by newbie questions, tooo much advanced stuff operating in my mind.
Learn & know C4D well before making such requests for features already in use for a decade now... :D
Title: Re: Perspective Correction
Post by: edofante on 2017-06-27, 10:17:48
shift correction is different from tilt correction. In the first case you only move in X-Y the focal plane, in the second you rotate the sensor plane. In my opinion have the tilt correction will be amazing, i miss very much this things from vray camera

Title: Re: Perspective Correction
Post by: houska on 2017-06-27, 11:01:19
Yes, tilt is in the Camera Object... i get confused by newbie questions, tooo much advanced stuff operating in my mind.
Learn & know C4D well before making such requests for features already in use for a decade now... :D

Consider me a n00b too, as I don't know a lot of features that C4D contains.

The film offset does pretty much what you'd expect it to - offsets the sensor by moving it relative to the lens. But you cannot achieve straightening of vertical lines by just shifting the sensor.
Title: Re: Perspective Correction
Post by: houska on 2017-06-27, 11:06:01
You can achieve the same effect by using the film offset Y option in the camera object so long as you keep the camera perfectly horizontal and vertical. Then just use the Y % spinner to move the view up or down and the lines will keep vertical. No need for a plugin/script.

Ah, maybe I understand now :-) The thing is, you cannot afford to have your camera "perfectly horizontal and vertical" at all times. Sometimes you might want to look up at some building that is too high to fit in your frame without looking up and in that case you might want to correct the vertical lines.
Title: Re: Perspective Correction
Post by: houska on 2017-06-27, 11:13:38
Another post from me (sorry :-D)

I found this thread: https://forum.corona-renderer.com/index.php?topic=10969.0

Mor4us describes the problem in slightly different words and now I know what you guys mean by saying that vertical shift is enough... I'll ask what Ondra thinks about this when I see him. But if 3DSMax version includes the correction in the camera that they are working on, there is no reason to not have it in C4D too.
Title: Re: Perspective Correction
Post by: edofante on 2017-06-27, 11:21:03
 check  https://en.wikipedia.org/wiki/Tilt%E2%80%93shift_photography (https://en.wikipedia.org/wiki/Tilt%E2%80%93shift_photography) in the paragraph Camera Movement > Tilt for more info. Please implement this feature!
Title: Re: Perspective Correction
Post by: burnin on 2017-06-27, 12:20:24
Ahhh, tilt lens is another story. Should state that in the first place. Must admit i had never heard of an engine doing tilt lens effect (deforming a focal plane). Usually is faked in PS or other image editing app.
Also, from reading here (https://forum.corona-renderer.com/index.php/topic,832.msg6672.html#msg6672), max shift implementation seems wrong?

Still confused...
Title: Re: Perspective Correction
Post by: ozwald on 2017-10-16, 17:05:19
Yes, tilt is in the Camera Object... i get confused by newbie questions, tooo much advanced stuff operating in my mind.
Learn & know C4D well before making such requests for features already in use for a decade now... :D

Greetings friend. if you look on the internet what is correction of perspective you will realize that I am speaking ....
I think that before writing you should find out more about the subject ........
is the same vertical shift / horizontal shfit, camera vray

To include it in a corona would be spectacular
thank you all for your contributions