Creating Oblique Images - Anamorphic

[Anonymous]

Ive being working with autocad for a few days now trying to figure out how to create oblique images. 

what i exactly want to do is, to place a 2D image and would like to look at it from the camera, while i look at it from the camera it should have a 3D perspective. 

I believe this is possible on AutoCAD but i cannot find any tutorial on on this nature. 

this link shows it. 

https://www.google.lk/search?q=redbull+anamorphic&rlz=1C1CHWL_enLK630LK630&espv=2&biw=1366&bih=653&s...

[SEANT61]

Not a tutorial, necessarily, but this blog post has some information about the process:

http://through-the-interface.typepad.com/through_the_interface/2012/08/creating-3d-street-art-using-...

If anything, the blog talks about a shortcut to create anamorphic projection using 3D AutoCAD geometry.  Down in the comments, I responded with a similar, though alternate, method.

Do you have a specific scene/geometry in mind?

[Anonymous]

THanks for your reponse. 

Yes but the thing is that its a 3D object transformed into 2D by using a flatshot command. 

What I want is to draw an oblique image so it would show 3D to the camera view.  

[Anonymous]

abdullahhh,

Flatshot is only a part of the process explained in the article. Continued reading will explain the custom command "Skewshot" that transforms the geometry of the flat shot into the anamorphic projection.

[steven-g]

Wow I used to work with one of those street artists about 10 years ago, I had heard he travels around the world now.

Abdullahh, doing something like that in Autocad is possible, but it is much easier starting from a 3D model and then projecting it onto the plane that you want. If you really want to draw it directly as a 2D image then I would suggest looking up tutorials on the traditional methods of drawing perspectives, but be warned it is a learning process. Good luck and please show us some of your work when you get going.

[Anonymous]

ermmm, what exactly happened was i got stuck with the flatshot command itself as it doesn't work well on my version of AutoCAD..

I will try the skewshow command, and will get back on the progress. thanks alot for the response though.

[Anonymous]

yeah, i've being looking up at some tutorials wasn't very successful in finding one though, i'll update you guys on the progress.

[SEANT61]

I demoed a 2D/3D method for this type of projection in the comments of the 'Through the Interface' blog posting I linked in post #2 of this thread.  The crux of my method was the use of a 2D projective transformation process as provided by routines contained in these links (membership at sites may be required):

http://www.theswamp.org/index.php?topic=48029.msg530659#msg530659

http://www.theswamp.org/index.php?topic=36905.0

https://apps.exchange.autodesk.com/ACD/en/Detail/Index?id=appstore.exchange.autodesk.com:stsc_projec...

Generating the anamorph is convoluted process to be sure - especially since the base geometry needs to be model first in 3d.  A little patience, though, and some viable results can be had.

Here are the test results; anamorph3d.dwg has the original 3d geometry, anamorph2d.dwg contains the results.

[Anonymous]

so now i've got my camera on autocad set with the distance and height of which i want to see the image appear 3D from. what should i do next. i went through the link you posted in the forum. seems a bit like greek to me, could you possibly break it down for me? im sorry for the trouble just need to get this going. 

And i have also installed Projective 2D on AutoCAD. 

[SEANT61]

Here’s a basic Tutorial using the Flatshot/STSC_Projective2D commands:

I’d like to paint a logo on a field that is 25 meters in front of a camera. The camera sit 15 meters above the field plane. The image should represent a sign 3 meters tall, 4 Meters wide. The sign will have some generic logo, of which I have Vector artwork.

In AutoCAD, I create the Camera with a position of 0, -25, 15. The Target is set to 0, 0, 0.

I create a 3DSolid Box, -2, 0, 0 by 2 , 0.1, 0 with a height of 3. I will need reference geometry in the form of a rectangle on the ground plane so I create another box, -2, 0, 0 by 2, -3, 0 with a height of -0.1. (This, and all resultant evidence of this reference geometry will eventually be discarded)

With a view from the Camera, I call Flatshot – and position the results to the side of the 3d geometry. Flatshot inserts it’s geometry as a Block Reference, so I explode that back to standard lines.

For the sake of better visibility, I go back to the standard Top view. Further to the side, I create a Rectangle that is 4 x 3. I position the logo into this “Square Rectangle” as I’d like it to appear.

I start the Projective2D command, make sure the initial setting is “From Ortho”, snap to lower left of the “Square Rectangle”, then upper right. I select the logo, then I select, counter clockwise from lower left, the four corners of the Flatshot generated lines that represent the Sign. The logo geometry should now match slight perspective of the Flatshot.

I call the Projective2d command again, this time switching the initial parameter to “To Ortho”, select lower left of the 3d reference box, then upper right, Select all the logo geometry that has the slight perspective, Then, counter-clockwise from lower left, select the corners of the Flatshot’s reference geometry. (Note: snap to the corners representing the top surface). 

The result of that second call should recreate the proper logo when seen from the Camera.

[Anonymous]

Hi Sean, 

Sorry for the late response. i've being travelling lately. 

I will check on this and let you know how it goes. 

once again i wish to thank you guys for all the support. Much appreciated.