Polylines to hatch in autocad

How to export polylines created in Grasshopper which appear as hatches in Autocad?
I have approx. 20.000 polylines. Right now I am using Human’s hatch widget, but it takes forever until it creates them. (30 minutes). Any quicker soulition?

post screenshots or the definition

I did

try with ELEFRONT define hatch ; when you bake it you get hatch not lines

I have installed it and tried, with the enclosed definition. Does not seem to work. Canvas%202

Bake it with right click on the component

Is there a way to colorize the solid hatch and define a layer and group them?

Are you trying to “define” a new hatch pattern, or use an existing hatch pattern and fill boundary curves? I’m pretty sure that the screenshot above, (with the elefront hatch and bake component), does not define a “new hatch pattern”…so to speak. It looks at the currently active Rhino Document, retrieves the available hatch patterns, takes the boundary curves(C input of hatch), and upon baking, will create the hatch object/s in Rhino. Pretty sure you can add attributes to the object when baking, (layer, color, etc)
Maybe I misread the intention, but creating a custom hatch pattern, would require creating and adding a hatchpattern definition to Rhino.RhinoDoc.ActiveDoc.HatchPatterns table…which might be kind of cool to be able to do from GH, but I think it would require a little more work.
a hatch pattern “definition” can be grabbed from other rhino(3dm files), or a .pat file.
They are just text files, and look like this: (just two for examples sake)

; Rhino default Hatch Pattern file
; Explanation
;first value   = angle
;second value  = starting line point X Coordinate
;third value   = starting line point Y Coordinate
;fourth value  = next line shift along the line direction (relative to X Y coordinates) 
;fifth value   = next line shift perp. to line direction (angle +90°)
;sixth value   = mark length
;seventh value = gap length (usually negative)
*Hatch 1x45
45, 0,0, 0,1
*Hexagon 
0,0,0,0,1.7320508,1,-2
0,1.5,0.8660254,0,1.7320508,1,-2
120,0,0,0,1.7320508,1,-2
120,0,1.7320508,0,1.7320508,1,-2
60,1,1.7320508,0,1.7320508,1,-2
60,1,0,0,1.7320508,1,-2

probably more info that required/requested.

Actually I wrote, that I need a solid hatch which is already included in Rhino. My probelem is that I dont know if it is possible to group them. Also I am not sure that it works for high number of curves (20.000).
Actually it works only for a small amount of curves for me.

ah, I see. I think 20,000 curves might be a little to much to do at once. To your direct question, assuming you are using elefront, you can assign color and layer by creating/adding attributes. At least in Rhino 6, if you add a group parameter before the bake component, it will bake the grouped hatches.

Thank you. If 20 thousand too much at one, do I save time if I split them to smaller chunks?

I would bet it would. The baking part happens pretty quickly, but the gh/elefront part of creating the hatch objects can start to slow down as the number goes up. Maybe chunk it down to 1000 curves to start with and see how fast it goes.