Camera Match

[joey altalef]

Hi everyone

 

Im getting an odd result with the camera match option. For the Camera Match object I have a photo with a nice and clear perspective view, making it very easy to manage and arrange the control lines (R1 R2 L1 L2 V1...). I'm uploading some pics and the VW file of the  columns I want to add to a long corridor. 

 

Pic1 - the columns im trying to add

Pic2- the Match opbject picture with the arranged control lines

Pic3- the desired result

Pic4- Camera Match result.

 

Sometimes I get a message that the control lines are reversed, Im not sure why.

 

any thoughts?

thanks

joey

VW 2017 SP3

 

columna.vwx

Edited May 21, 2017 by joey altalef

[Christiaan]

Hi Joey, you're trying to go to a single vanishing point with both control lines when Camera Match needs to two vanishing points (indicated by the red and blue arrows of the CM reference). A natural mistake to make with a photo like this.

 

You'd be better off with a photo taken off to the side of corridor rather than straight down the centre. It's difficult to match because you're essentially perpendicular to one set of the control lines, making them almost parallel to each other and so very prone to error (i.e. any small movement of them will have a large effect).

 

I've had a play around with the file and got it roughly into position, but I need to go out so I'll leave it with you to refine. I also recreated the Reference (your one had been rotated 90º and I think this can be a source of problems). Is your model the real world width and length of the corridor? If not you'll need to correct it somehow (even if just by trial and error).

columna.vwx

Edited May 21, 2017 by Christiaan

[Matt Panzer]

Christiaan is right on all accounts. As he mentioned, using a similar photo but slightly panned to the right or left (so the vanishing point is not so close to the center) will help a lot. I think it's worth mentioning that cropping the photo so that the vanishing point is more to the side will not help because it will not change the actual perspective of the photo.

 

I adjusted the left (green) control lines a bit more, made "L1" the measured line and gave it the same dimension as in the model. Also, if you haven't used the preview object in Camera Match, give it a try. Views similar to one point perspective can be tricky, but the preview object can help.

 

Notice how the right plane of the preview object (below) fits nicely against the right wall. If you slightly move a free control line up or down, you'll notice this plane rotates away from the wall. Using the preview object lets you make slight adjustments until the planes fit the perspective of the photo better.

 

Here's the Camera Match view with a little fine tuning:

 

columna.vwx

[zoomer]

That's again one of those perfect examples of Photos that aren't suited for Camera Match

which Matt explains in his Videos.

 

And such a Photo of a "central" or one point perspective is also an example where Camera Match

isn't needed at all as you can match your camera manually very easy.

In most cases you can grab the Cameras Focal Length out of the EXIF data, Camera Height

will be about 1,6-1,7 m and with the help of a bit of dummy geometry perpendicular to camera

you just have to dolly back/front/left/right your camera until it fits.

 

Some real world size and scale knowledge is mandatory or your inserted virtual geometry

and placement will not make much sense anyway.

[joey altalef]

thank guys!

helped me a lot.

that was a nice mistake I made 

[Christiaan]

5 hours ago, zoomer said:

And such a Photo of a "central" or one point perspective is also an example where Camera Match

isn't needed at all as you can match your camera manually very easy.

In most cases you can grab the Cameras Focal Length out of the EXIF data, Camera Height

will be about 1,6-1,7 m and with the help of a bit of dummy geometry perpendicular to camera

you just have to dolly back/front/left/right your camera until it fits.

 

Ha, nice one, hadn't thought of it that way 👍🏼

[zoomer]

Yes, many photos are pretty easy and predictable.

You look at Google Earth, see traffic on the photo, so the one who did the shot was

not in the middle of the street but maybe on the pedestrian way, and you can assume

the standpoint. Maybe even get the EXIF.

Given some lens distortion you will be faster and create a more "realistic looking" result

manually.

 

Matt's gem comes into play when you get an edited Jpeg without EXIF, the photographer stood

on a ladder at POV Z=2,80 m and rotates his camera in 3 Axes.

 

That is where Camera Match is mandatory and at the same time where it works best.

Edited May 22, 2017 by zoomer