Search found 439 matches

by Mark Szlazak
Sat Dec 24, 2022 8:56 pm
Forum: Help on using FreeCAD
Topic: Central Projection of sketches, part edges onto datum plane in 3D
Replies: 8
Views: 1031

Re: Central Projection of sketches, part edges onto datum plane in 3D

edwilliams16 wrote: Sat Dec 24, 2022 7:56 pm It works either way.
Thank you!
by Mark Szlazak
Sat Dec 24, 2022 8:16 pm
Forum: Help on using FreeCAD
Topic: Central Projection of sketches, part edges onto datum plane in 3D
Replies: 8
Views: 1031

Re: Central Projection of sketches, part edges onto datum plane in 3D

drmacro wrote: Sat Dec 24, 2022 7:55 pm Is this for optics?

There is an Optics workbench.

Though, I'm not sure it does any 3D.
No i need it for a geometric proof about the tangent points of a quadralateral with a sphere.
by Mark Szlazak
Sat Dec 24, 2022 7:40 pm
Forum: Help on using FreeCAD
Topic: Central Projection of sketches, part edges onto datum plane in 3D
Replies: 8
Views: 1031

Re: Central Projection of sketches, part edges onto datum plane in 3D

edwilliams16 wrote: Sat Dec 24, 2022 7:20 pm point projects onto a face.
Yes this is correct but i will be doing in reverse where a plane between the object and the point gets intersected by rays to form an image. So in the picture i attached, points A, B and C would be the result i am looking for.
20221224_113034.jpg
20221224_113034.jpg (45.44 KiB) Viewed 937 times
by Mark Szlazak
Sat Dec 24, 2022 5:46 pm
Forum: Help on using FreeCAD
Topic: Central Projection of sketches, part edges onto datum plane in 3D
Replies: 8
Views: 1031

Central Projection of sketches, part edges onto datum plane in 3D

Is there a way to do central projections in 3D onto datum plane (sketches or faces). This means that i define a central projection point to do the mapping of an object onto some plane in 3D based on this center point. Is that even possible in FreeCAD?
by Mark Szlazak
Sun Oct 16, 2022 8:08 pm
Forum: Help on using FreeCAD
Topic: Image Workbench Placement Errors??
Replies: 7
Views: 832

Re: Image Workbench Placement Errors??

The image workbench scales with a graphical input based on a line one creates. If you have already the scale information like I do (1mm = 3042 px) is there a way just to input that? You can enter an expression such as 1234/123 directly in the property field. FreeCAD will calculate the result and en...
by Mark Szlazak
Sun Oct 16, 2022 12:18 am
Forum: Help on using FreeCAD
Topic: Image Workbench Placement Errors??
Replies: 7
Views: 832

Re: Image Workbench Placement Errors??

Oh I see the mistake you made: 1.08/2=0.54 and not 0.504. I didn't realize, because I use Expressions . Then no matter how you scale, upper right edge will be at (0,0). OMG! :lol: Thanks. It's Saturday and I haven't even started drinking yet. I have a question. The image workbench scales with a gra...
by Mark Szlazak
Sat Oct 15, 2022 10:40 pm
Forum: Help on using FreeCAD
Topic: Image Workbench Placement Errors??
Replies: 7
Views: 832

Re: Image Workbench Placement Errors??

From what I see here, the scaling is done around the center, and in my tests the formulae you used work perfectly. Is there something weird with the image? Can you upload it? The file is to large and this site will not accept it but here is a link to the image and you can down load it from there. h...
by Mark Szlazak
Sat Oct 15, 2022 9:46 pm
Forum: Help on using FreeCAD
Topic: Image Workbench Placement Errors??
Replies: 7
Views: 832

Image Workbench Placement Errors??

I don't know if it's me, some bug in this workbench or something else. When trying to place an image using the Image Workbench tool I do not get what I would have expected based on my calculated placement offsets. They are meant to place the upper-right-hand corner of the photo at the origin of a ov...
by Mark Szlazak
Fri Oct 14, 2022 3:38 am
Forum: Help on using FreeCAD
Topic: Is it possible to work in units of microns in FreeCAD?
Replies: 8
Views: 883

Re: Is it possible to work in units of microns in FreeCAD?

If you don't change the initial size you can reposition the image with setting x and y component of the placement: set x to XSize / 2 set y to YSize / 2 Great, thanks! Makes sense but I did not see it mentioned that the default positioning is the center of the image. Maybe someone can mention that ...