How to get the (2D) projection of a solid?

[maisoui]

Hi,

After several tests / research, I still can not correctly calculate the (2D) projection of a solid. For example, I want to obtain a circle/ellipse for a sphere (with or without obscured lines) (something similar to command FLATSHOT). I tried to use Brep API, but without success (execution time very very long or eDegeneratedTopology error).

My goal is to display any projection of a given solid in a custom entity. Perhaps there is a simple way in subWorldDraw or subViewportDraw?

Several posts in the forum talks about the same topic, but were never answered.

Any suggestions are welcomed. Regards,

[dgorsman · Accepted solution]

I *think* what you're looking for is the HLR API (hidden line removal). 

[maisoui]

Perfect. This is exactly what I was looking for. After reading the few Hlr examples that come with the API, I was able to implement a 2D projection of a solid, and it computes fast.
Many thanks for your help.
Regards,