Panorama Background

[Brett Brown]

Hi,Is it posible in Archicad to use a Panorama photo of your site as the background so when creating a Fly-Through you would see a different and true outlook from every room in your house?If so what would be the process.Using 8.1

[Dwight]

Yes it is.

Map your panoramic photo to the inside of a giant - and I mean huge - cylinder - most easily made from a circular wall. Calculate its height using math - Pi the diameter equals circumference, etc.

When you make the cylinder the wall will automatically split in two - at the 180 degree points - mapping the same half of the panorama twice.

You must split your panorama in two, mapping each half to the correct wall segment by making the split-in-two panorama photo into material textures and if necessary to align, use the 3D origin assignment tool to exactly place the origins of each material.

There is also a GDL method we have elaborated in David Nicholson-Cole's GDL Cookbook, where material mapping is simplified.

[Brett Brown]

Hi Dwight,Is there a rule for the size of the cylinder in relation to the size of the photo for focus and is this covered in your book "Illustration in Archicad" in more detail.I ordered it a week ago and haven't received it yet.Thanks.

[Dwight]

Things get indistinct when the size of one pixel of texture map exceeds one pixel of rendering size. The rendering engine has to make it up and averages out the differences - blurring it.

The exception is with really tiny textures where you want the pixel edges to show as checkerboard patterns where even a single pixel mapped as large as a metre square and viewed close looks sharp on its edges because the blurring is only one pixel of rendering size....

For maximum clarity either turn on Texture Antialiasing in the rendering preference or make the rendering double size and reduce in Photoshop using "bicubic sharper" resampling - might be faster depending on your machine.

[Anonymous]

why is there no panorama object available in which a background image could be placed?

[Dwight]

And I wonder wonder who do do do. Who wrote the book on love?

Our GDL Guru David Nicholson-Cole coded a cyclorama once.
The explanation and code can be found in the GDL Cookbook 3, page 2.150

It has a serious drawback in that while it makes an effective background, the illustrator needs more control over the appearance and orientation of the image. For instance, being able to make it constantly reflect light regardless of the sun direction. [Vital, no?] At this time with GDL technology, the most effective way to achieve this is to create a material against a curved wall.

You can download the GDL Cookbook at:

http://www.nottingham.ac.uk/sbe/cookbook/CB_download/cookbook3download.html

You can find the details on more useful cycloramas in my book on page 152

[Anonymous]

Very cool idea. I wonder, would using a complex profiled wall with a slightly concave section - say, equal to the radius of the cylinder - give a more realistic effect?

[Dwight]

You mean to take a horizontal slice from a sphere.

It probably would be useful if there was that much detail in the rendering or the background photo itself, but these backgrounds are used for flythrus, tiny ugly efforts ruined by compression. And, really, the sky portion doesn't have enough information to notice.

Look at the ways backgrounds are used in by real moviemakers, notably, the restaurant scenes in "Fifty First Dates." They construct an absolutely surreal but convincing restaurant interior - more convincing than a real one like filmed in "Pulp Fiction," using still photo backgrounds - flat.

And "The Matrix" - those skylines are all flat cycloramas.

I put the cyclorama wall fifty metres away and merely glimpse it thru condo windows. Too small to notice.

Now, if you want to put more effort into "reality," a trick worth the effort is to do a mid-ground cyclorama with an alpha channel masked sky. This is totally fake since in a real site panorama photo, it isn't practical to cut out buildings - they are already IN the background, but fake buildings and tall trees moving relative to the background while you camera flys thru are entertaining.