Crazy path tangents

[shakingearthdigital]

Hello, 

I feel like I'm missing something basic. I'm drawing a path on a super simple straight surface, and instead of being a straight path, it's bending all over the place. I tried toggling corner/smooth, which does *something*, but certainly doesn't make the path straight:

What is happening? How do I create a straight path? 

Substance 3D Painter, version 10.1.2
Build 4105 - 5ac1e5465eedb521dd6c13c1a61a8eca1ecc27d0

[Cyril Dellenbach]

Hello @shakingearthdigital,

Thank you for the message.

From your screenshot, it doesn't look like a perfectly straight surface (but I could be wrong). Our Path system doesn't work like it would in a 2D software and the vertices are really "attached" to the 3D surface. Therefore, a Path can look straight from a point of view, but the tangent is in fact curved.

 

 I advise you to deactivate the custom tangent (the pink handles) and keep the "Corner" mode active.

Best regards,

[shakingearthdigital]

Hi Cyril, 

thanks for the reply. I'm not using custom tangents. The pink handles are from the 'Display' option. Turning that off doesn't change anything. 

I'm attaching a video, which hopefully demonstrates the issue better. Corner mode just doesn't seem to work. 

[carol_2691]

I have the same issue.  I have a flat plane, I create 2 path points.  The path doesn't create a straight line against the plane, it is curved.  The path should be a straight line between the 2 points but it isn't

[carol_2691]

You have 3 starting points in the video that have a straight line between them.  That is what is not working, I have 2 points, but the line between them is not straight.  If there are only 2 points on a flat plane's surface, why does my line curve away from the surface instead of following the path between the points

[carol_2691]

I have this same issue,  was there ever a solution for this?   Check my screenshot, I have 2 points, but the line between them doesn't go between them correctly it doesnt align to the mesh surface

[shakingearthdigital]

No solution, they ignored my reply when I pointed out that their suggestion didn't work. 

As far as I can tell, it's due to the normals on the surface, so one thing you can try is to create a version of the geometry that has cusped normals, and use that to draw lines on.