ALIGN VIEW CLARIFICATION

[Dwight]

One Way To Use the Align View Tool

Preamble:

The idea of an align view tool is remarkable and seems impossible. How could a few clicks on a picture provide the trigonometry to establish a camera viewpoint?
Of course, you’d have to be a wiener to NEED a tool like this. A real he-man would walk the camera into position using an OpenGL wireframe view. All things considered – the tool not being perfect [even Graphisoft’s instructions say “salt to taste” ] – the eye can get the camera angle and viewpoint close enough by trial and error. But if you need it, you need it.
I’m impressed with the computer and geometry knowledge of anyone at Graphisoft who would attempt to build this tool, considering the fundamental inaccuracies:

A: Camera distortion: the tool needs accurate heights to create the orienting plane. If the photograph is the least bit distorted or crooked from lens aberration, the dimensions won’t work.

B: Aspect Ratio: the tool works best on horizontal images with a fairly narrow view angle – under sixty degrees and a measuring plane centrally located.

C: Pixels in the Image: The bigger the better, since accurate placement of the visual coordinate is essential. One pixel of error will mess it up, so make your picture really big when placing it in the floor plan.

NOTE: This method DOES NOT address aligning view for photos. It addresses aligning a view using an ArchiCAD rendering to see exactly how precise the tool can be – using a “perfect” image: an image we know everything about with a camera viewpoint on the floor plan to compare to.

[Dwight]

STEP 1: Getting the image.
Render an image in ArchiCAD – it should have at least one vertical plane centrally located.
The example here is around 600 X 800 pixels.

STEP 2: Place the image.
Place the image as large as practical on the floor plan.

STEP 3: Do the Align View routine.
Make your Status Bar visible for step-by-step instructions. I sense that putting the top coordinate of each vertical first yields better results.

[Dwight]

Zoom in for precise placement of the image coordinates

[Dwight]

Sit back and see how close it got.

[Dwight]

And the result is pretty close, but no cigar.

Here seen as an openGL wireframe view from the align view camera position overlaid on the original view.

Conclusion: Not perfect but a good start.

[Anonymous]

I think this tutorial is also very interesting

[Anonymous]

So, I am attempting this Align View goobuldy-Gop.

I get how to put the image in and how to pick the points and line them up and all of this.

I, however, am having a problem with th positioning of my Model.
The model seems to be scaling fine to the picture, but it is too high.

Is there something in the "PhotoRendering Settings" Dialogue box I need to mess with?
Or is there something maybe I am doing wrong when I bring the Image in in at the start?

And... also, I am not being able to bring the whole building into the Photo Image, it wants me to select the parts i want in the Rendering, but I am doing this on only one floor 'cause that is all I can see at once in plan.

Any Ideas?

Thank You
Jessica

[Dwight]

Somehow you are entering "Z" heights too high. Try saying the wall begins at "0" instead of its project zero relative height....

[Anonymous]

isnt the "z" value actually deciding the height/scale of the model?
And the points that you are selecting on the image are deciding the placement of the model?
...

[Dwight]

post an image.