Select all faces seen by camera?

derwolk

hi,

is there a way to select all faces which can be seen from the current camera position?
what i want to achieve is this: create 2.5d model from the 3d model. like the result you get from a 3d scanner. 3D but just from one viewpoint

its like backface culling.. but i haven't found a solution yet

thanks a lot

walter

Alan Fraser

Hi Walter,
No, I don't think that's possible. I have asked for a "Select Visible" option a few times, but so far no luck.
The only way I can think you could do this at present would be (maybe on a duplicate of the model) to set up a scene with the required view, select a strong colour, then click on every surface you see (with hidden geometry turned on). Having selected it, group it, then delete everything else. Kind of labour intensive, but it works.
Unless I've missed it, I don't think there's a Ruby script that will select everything visible...although it doesn't sound impossible.

tbd

I did something similar some time ago - see discussion

honoluludesktop

Alan, If you did a left to right selection window first, wouldn't you get all the faces that are completely within the the scene? Then complete the selection by individually selecting the balance.

Alan Fraser

I don't quite follow that process, hd. I assume some kind of boolean selection, but don't follow how that would cull the back faces.
Actually...looking at my own description...I forgot to mention that the reason I gave for actually painting the faces was so that you could then use Select > All with same Material from the context menu.
I find it safer to do this than serialy click on a large number of faces, because somewhere along that route I usually mis-click and have to start the whole selection procedure over again. At least by physically painting those faces you have them 'under your belt', so any mis-clicks are no big deal.

honoluludesktop

Hi Alan, I missed your post. Perhaps I do not understand Walter's question, but the following is what I understand. Btw, by back face, do you mean the unseen faces behind the ones you can see in the scene? If so I did the following with some success.

"Select all" in the scene with right to left window, and explode as necessary to eliminate all components and groups.
"Select" in the scene with a left to right window, then "add" to "select"ed, the individual faces at the perimeter of the scene.
Make the combined selection into a component, using default name, but "do not replace selection with component".
Open component menu, select "model" components, select the default name component, then "save as" skp file.
The saved file, includes only the faces that can be seen in the scene. They include however, portions of the visible faces that are behind other visible faces.
Open the "default component name" file, but do not save changes to the original file.

Step 2 only selects the visible faces completely within the select window, and the balance of the faces along the perimeter must be individually selected. You can skip step 1 if you want the components, and groups to be part of the new file. It will however, contain the back faces within each component, and group.