Meshes Offsetting In Different Directions After Unify Mesh Normals

Hi Not sure why this is happening but I have a series of meshes offsetting in different directions after being run through mesh unify normals and mesh weld vertices (note: the light red meshes are offsetting -Z and the dark red meshes are offsetting +Z). I suspect is has to do with the direction of the mesh normals however I am not sure why this would be occurring after going through mesh unify normals. Any suggestions to rectify would be very helpful! (83.0 KB)

Yes, it is a mesh direction problem. This might be easier to solve before you get to mesh creation. Both the curve (Flip Curve) and surface (Flip) components allow for guide geometry, which can be the first item in a list or a mundane curve or surface to reference. I don’t know that there is a mesh equivalent with a guide input.

Though that is something of a band-aid of course. I find it useful to go through the base geometry, bake and use Dir command to manually find the direction discrepancy, little things can cascade.

Thanks for the response! Unfortunately I can not bake any geometry into this as I need to maintain the adjustability of parameters throughout the whole system. I would also like to maintain the mesh geometry outputs at the end with as few surfaces as possible to keep the computation as light as possible (will be running the system through radiation analysis and optimization eventually). The issue only seems to be with the lofted geometry. Would it be possible to apply your solution to these lotfs prior to converting to mesh?

Thanks again!!

I only mention baking for analysis, there are components that show curve/surface directions but I personally just like to bake and manually identify.

Your curve directions just need to be matched up, flip curve with a guide curve works, but again, just a band-aid. Depending on what you use as a guide curve, it may not be adaptable to different forms. Rather than refencing a List Item in my example, which may end up choosing the wrong curve, a better guide should be found, like an independent arc or rectangle.

I didn’t work my way back to the beginning, there may be a more obvious point where directions deviate, fixing that could be a more permeant solution. (82.4 KB)

I see now why you say it is only a band aid solution. As I increase the number of grid cells the issue returns, however now all of the meshes oriented in the wrong direction are within the same group. Thanks for the help! I think I know how to get this resolved on a more permanent basis now.

Will upload the solution if i get it working


You can try just a vanilla rectangle as the guide. That seems to adapt fine but could break at some point as well. It’s pretty predictable on planar curves but gets dicey on non-planar, if your guide and target aren’t similar enough.

that worked perfectly!! never through of using a plain jane rectangle as the guide. Probably just didn’t fully understand how the guide was working.