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Equirectangular panorama images and cubic QTVR movies from Bryce scenes

By PMEDig (www.pmedig.com)

Introduction

Bryce gives you the possibility to render 360° panorama images and QTVR panoramas but these are rather limited regarding the vertical FoV (Field of View).
A DAZ tutorial describes the transformation of 6 images with 90° horizontal and vertical FoV (oriented to the 6 faces of a cube) into cubic QTVR movies, using the freeware GoCubic.
This tutorial will deal with the generation of a equirectangular panorama image by using a mirrored ball. The equirectangular image can easily be turned into a cubic QTVR.

Mirrored ball

Using a mirrored ball is a widespread method for the generation of panorama pictures (tutorial example).

There are three disadvantages:

In Bryce these disadvantages are not present:

Preparing the Bryce scene

 

01. Open your scene in Bryce.



02. Go to document setup and adjust the document resolution size to a square format (e.g. 600x600).


03. Add a sphere to the scene and click A.

 

04. Name the sphere "mirrored ball" and place it at the position where you would place the camera (in this scene x=0, y=10, z=0, just above the marble stone).


05. Adjust the size of the mirrored ball to x=5, y=5, z=5.

 


06. Go to the Materials Lab (click M) and choose Mirror from the "Easy & Fast" category.

 

07. Adjust Diffusion and Specularity to 0 and change the color of Diffuse, Ambient etc. to white.


08. Go to the Material Options and uncheck Cast Shadow, Receive Shadows and Self Shadows. You can save this preset as "mirrored ball" for future use.

 


 

09. Select the perspective camera, click A and place the camera at position x=0, y=368.09, z=0.

 

10. Adjust the FoV to 1.

 


11. Go to the tab Linking and set the Object Parent Name and Track Object Name to mirrored ball.

 

 

You should get a scene similar like this:

 


 

12. Choose Camera View and render the scene (preferable render dimension 3000x3000 for a good quality of the QTVR later).

 

 

13. Save the image as tiff.

 

Equirectangular panorama

For the transformation you need the free Photoshop plug-in Panorama Tools of Helmut Dersch.

 

01. Open the mirrored ball image in Photoshop.


02. Go to Filter -> Panorama tools -> Remap.


03. Check Convert from: Convex Mirror to PSphere (=equirectangular), HFOV=360°, VFOV=180°.

 


04. Click the Preference button and uncheck a and check b and c.

 


05. Click OK to perform the remapping. You will get an image like this (original size: 4712x2356):

 


06. This is a mirror image, so go to Image -> Rotate Canvas -> Flip Horizontal to correct this.


Now we have a equirectangular panorama image of the scene.



Cubic QTVR movie

The equirectangular image can be turned into a cubic QTVR with for example pano2QTVR (free version available). A Flash tutorial for this transformation is available on the pano2QTVR web site.

 

-> Cubic QTVR (521KB) of the above scene

Nadir

If you look down on the marble stone in the above cubic QTVR, you will notice that this area is distorted.




This is the nadir, the area behind the mirrored ball which is not captured. There are several possibilities to retouch this area.
A nice solution from Peter Nyfeler is to add a mirrored ball (with or without text) at this position via a photoshop action.

 

-> Cubic QTVR (530KB) of the above scene, nadir retouched

Distance between the mirrored ball and the camera

To get a render of the mirrored ball exactly centered and the edges of mirrored ball touch the sides of the images, the distance has to be carefully adjusted. The distance between the camera and the ball can be calculated using this formula (camera FoV=1):

s=d/2*tan(0.4)

 

The FoV of the camera in Bryce is not very accurate. The FoV is actually 0.8.

 

Mirrored ball diameter in Bryce Units:

Mirrored ball - camera distance in Bryce Units:

Remarks

The camera doesn't have to be above the mirrored ball. It can also be in the horizontal plane of the ball. The nadir however will be at a different (unfavorable) position.

 

Very small mirrored balls (e.g. d=0.1396, s=10) can also be used. Then the possible reflection of the mirrored ball by other reflecting objects in the Bryce scene is minor. Also great for crowded scenes!

 

As the perspective camera is a child of the mirrored ball, the mirrored ball can be moved in the scene and the camera stays in the correct position to capture the ball. You can make equirectangular images at different locations in your scene and link the resulting QTVRs with hot spots (pano2QTVR) to make virtual visits of your scene!

 

 

-> Cubic QTVR (465 KB) of the above scene

 

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