CGTechniques.com 
Christian Bauer; 5/2001

How to get rid of the Photographer

 

This is an old tutorial i wrote to remember how i did it, but since some month is a better tutorial on the Hdrshop webpage.

 

If you still want to enjoy the chaos in my brain then read on:

 

When we make a Photo of a shperical mirror, we always have the photographer on the image.

To get rid off the photographer you have to take two pictures of a mirrored ball at ninety degrees of separation and assemble the two pictures into one picture.

1. At first we need the free Photoshop plugin PTOOLs from

http://www.fh-furtwangen.de/~dersch (which is offline) or http://www.all-in-one.ee/~dersch/ (a mirror)

Install it and open the first image. The first task is to remap the mirror to a Spherical rectangle image.
Please don't forget, that the Mirror have a full 360° Horizontal FOV and 180° VFOV.

PTools rescale the picture and open it in a new window. (you have to configure that)..just recognise the rotated image!

 

2. The next task is to rotate the Panorama and make the result as the default Panorama.

We go to the Adjusttool and convert it from PSphere to a PSphere with HFOV of 360° on both. We want to roll the panorama ( just like roll a camera to get a landscape) and we also rotate the pitchangle with 90° to get the center out of the corner.

If you are ready go to the actionmenu and import the Actionset which was ship with the PTools. Change to Buttonmode and click "apply" on the result.

Now just do the same with the second Picture with only one difference. The Pitchangle is 0. Don't forget to apply it !

Well this depends on the picture. Maybe you have to change the rollangle to 180°.... this depends on the starting picture. We started with the picture where the photoprapher was on the right side and on the second picture he was standing on the left side. ( he turns 90°).

3. We have now two pictures. The upper Picture is the second. Since we said "apply" to the second picture we lost the panoramainformations from the first, but this doesn't matter.

We copy the clean parts from the first picture to the second, flatten the image and "Apply" it with the action. If you now change something in the "buffered" second picture and "Apply" it, everything will be stored and can be converted back to a Polarmap.

The finished picture should look like that. You can take it and use it as a Spherical map in Lightwave or MAX.

But we want to finish the session with converting it back to a Polarmap.
We need two steps, since PTools can't convert PShere into a concave Mirror.

4. Now we have to convert it back to the internal buffer of PTools with "get Pano". IT converts it back to the remapped and adjusted picture like below. We need this step because PTools can only convert Vertical Fisheye and if we use the result of before, it would be a Horizontal Fisheye.

The first conversion will be from PShere to Fisheye Hor.

The second conversion from Fisheye Hor. to Convex Mirror. We have to rotate the Picture.

That's it

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