How to flip surface normals

Hi guys, I tried to flip surface normals but with no results. What is the right approach to flip surface normals outwards (green)? Some vector are right, some no. Hope that someone could help me!! ;-)

Replies to This Discussion

Permalink Reply by Raul Matagringo on June 21, 2013 at 1:27am

Hi,

first you have to find out what is IN and what is OUT. This can be very complicated in 3D space...

You can try to build the bounding box for the structure and then check which window is next to which side of the bounding box.

Permalink Reply by Landscape on June 21, 2013 at 2:48am

Hi Raul. Yes it's complicated in 3D space. Maybe if I use "bounding box" doesn't work because floors aren't regular as square/rectangle. I would like to find a short solution for this.

Permalink Reply by Raul Matagringo on June 21, 2013 at 3:02am

the floors aren't regular but each window shows in a "normal" direction (+/X or +/-Y).

Maybe you can also try to translate/transform the window shapes and the corresponding vector to the ground (XY). Then you can decide whats UP and whats DOWN.

Permalink Reply by Yasser Hafizs on June 21, 2013 at 5:33am

Hi Landscape,

Why not using normal vectors from wall surfaces? It's automatically directed to the outside if you extrude it, just make a group of windows curve by closest distances to the wall.

Another approach will be same as Raul said, make a closed brep with floor surface, move windows centroid with their own normal vector, check which normal vector are directed to the inside with brep inside, pick the wrong curves, then flip it with transpose method (custom script).

Permalink Reply by Landscape on June 21, 2013 at 8:07am

Amazing, it works!! Thank U Raul & Yasser!! ;-)

Permalink Reply by Yasser Hafizs on June 21, 2013 at 9:29am

Glad to hear that, :)

By the way, here's more simpler way: