I always have a difficulty getting a kosher match in perspective between a model and a photograph. The procedre is simple enough, camera position is measured on site and brought into DataCad via survey, but getting it right first time seems more down to luck than management.
The camera position is defined in the model by a fat post of appropriate height and this is the eyepoint for the perspective. This can be tested in DataCad and then the package taken through to a renderer, where the post is used again for the camera therein. Needless to say, if it is decided to relocate the camera because the perspective doesn't match the photo, you really need another post. If you are slack and set the perspective, and indeed have what you want, but without a new post, salvation is at hand.
The current eyepoint is offered to you when you select S1 SetPersp and the screen scale will be at something obvious, like 1:500. You can record this with the PrintScreen key, and paste this as a new image in a graphics programme. You may then trim this to show just your drawing area. It pays to bucket the background white, so that you can tell it apart from the screen....
With the plan view of the model at say 1:500, you can insert the cropped bitmap and size it to fill the whole screeen. I find it difficult to jam the second cursor point into the bottom corner but hitting Enter seems to fix it. This can then be moved over the model, with a minor scale adjustment if deemed necessary, and thus giving course and distance in order to copy the post into the new camera position. This is verifiable by going into the perspective view and stepping back 300. Part of the post should then come into view.
I can't get the pictures in order but the intent should be clear enough!
The camera position is defined in the model by a fat post of appropriate height and this is the eyepoint for the perspective. This can be tested in DataCad and then the package taken through to a renderer, where the post is used again for the camera therein. Needless to say, if it is decided to relocate the camera because the perspective doesn't match the photo, you really need another post. If you are slack and set the perspective, and indeed have what you want, but without a new post, salvation is at hand.
The current eyepoint is offered to you when you select S1 SetPersp and the screen scale will be at something obvious, like 1:500. You can record this with the PrintScreen key, and paste this as a new image in a graphics programme. You may then trim this to show just your drawing area. It pays to bucket the background white, so that you can tell it apart from the screen....
With the plan view of the model at say 1:500, you can insert the cropped bitmap and size it to fill the whole screeen. I find it difficult to jam the second cursor point into the bottom corner but hitting Enter seems to fix it. This can then be moved over the model, with a minor scale adjustment if deemed necessary, and thus giving course and distance in order to copy the post into the new camera position. This is verifiable by going into the perspective view and stepping back 300. Part of the post should then come into view.
I can't get the pictures in order but the intent should be clear enough!
Attachments
The Dcad model inserted into the picture
work1.jpg (225.26 KiB) Viewed 11482 times
work1.jpg (225.26 KiB) Viewed 11482 times
The camera position verified
posttop.jpg (75.03 KiB) Viewed 11482 times
posttop.jpg (75.03 KiB) Viewed 11482 times
The PrtScn image back in DataCad
Dcadv.jpg (73.53 KiB) Viewed 11482 times
Dcadv.jpg (73.53 KiB) Viewed 11482 times
Nick Pyner
Dee Why Beach NSW
Dee Why Beach NSW