# STL models showing stripes in CNC preview **URL:** \ **Category:** Snapmaker Luban\ **Created:** [January 16, 2022, 11:02pm UTC](https://forum.snapmaker.com/t/stl-models-showing-stripes-in-cnc-preview/23646 "2022-01-16T23:02:34Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Jack4501](https://avatars.discourse-cdn.com/v4/letter/j/ecae2f/32.png) [@Jack4501](https://forum.snapmaker.com/u/Jack4501)\ **Post date:** [January 16, 2022, 11:02pm UTC](https://forum.snapmaker.com/t/stl-models-showing-stripes-in-cnc-preview/23646/1 "2022-01-16T23:02:35Z")
I am trying to import an STL model for a CNC relief carving. The STL preview looks fine, but when I generate in gcode and preview the simulation, it shows strange streaky lines. See image below. Any idea what causes this or how to fix it? Or, will it actually carve those lines or is it just a visualization error? ![image](https://us1.discourse-cdn.com/flex022/uploads/snapmaker/original/3X/3/c/3c5378b3f30b4f704eec57e96a8b3e70060a0488.jpeg) ---
**Author:** ![ElloryJaye](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.snapmaker.com/elloryjaye/32/13979_2.png) [@ElloryJaye](https://forum.snapmaker.com/u/ElloryJaye)\ **Post date:** [January 16, 2022, 11:40pm UTC](https://forum.snapmaker.com/t/stl-models-showing-stripes-in-cnc-preview/23646/2 "2022-01-16T23:40:43Z")
Luban is prone to visualization bugs. Double-checking the gcode with a third-party visualizer like [NC Viewer](https://ncviewer.com/) should allow you to figure out if that’s the case here. ---
**Author:** ![seatoskylinemarking](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@seatoskylinemarking](https://forum.snapmaker.com/u/seatoskylinemarking)\ **Post date:** [February 3, 2022, 5:25am UTC](https://forum.snapmaker.com/t/stl-models-showing-stripes-in-cnc-preview/23646/3 "2022-02-03T05:25:00Z")
Hi i am having a similar issue but when i generate the g code i loose my original image all togther and just have the lines