Export shadows as linework?

Hi all! :slight_smile:

I know this question has been asked on here before, but I haven’t found any recent threads or anything with a conclusive answer.

I’m wanting to export the shadow cast within a model to linework, so that I can Make2D it and take it into illustrator. I’ve found a kind of awkward workaround where I extract the wireframe of the shadow casting objects, create a Cplane that would be perpendicular to the light source and then project onto my objects to receive the shadow, but this gets kind of messy and takes a while to tidy up the linework afterwards.

Any solutions much appreciated!

Hi stu - are the shadows on the ground plane or some terrain geometry?


I’m basically doing a series of internal views of tunnel-like spaces, and then there are a variety of openings on the ceiling and walls. So the shadows will be falling on both ground plane and walls/objects in the space.

Hi Stu - and, can the shadows be considered, for this operation, to be coming from one or more parallel light sources, or are they point sources?


A parallel light source works.

Hi Stu - here is a python script that may get you something - it is pretty hacky, but it may get you the curves you need, as well as some you don’t - you’ll need a plane for the ground plane for now, and it only casts and receives shadows on surfaces, polysurfaces and extrusions, not meshes, but these can be added.

Use RunPythonScript to run the script, or -RunPythonScript "Full path to script file in double quotes" to run it. You pick the objects to cast shadows and then the targets, then set two points for the light direction.
Now, it’s dumb - it casts the light forward and back along the direction vector and does not know about overlapping objects - i.e. nothing blocks the light…But it may help at least and it can be tuned up more on a rainy day.

Guaranteed somewhat tested.
ShadowCurves.py (2.1 KB)


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Could you save a render or screen shot and live trace it in illustrator?

Hi everybody. I was occupied with this topic aswell.
ArchiCAD does a fair job at Shadows as line work.
Illustrator can vectorise images…

What I just found out. If you

  1. create a Displaymode, with all Edges, Linework etc. set to 0px, shadowsettings clean/ maximup GPU usage, Antialiasing to 8x
  2. -CaptureViewtoFile with highresolution, and uncompressed you surpass the Sketchup Shadow display…

Im fairly content with the result, but would want to know, if it could get even crisper, … any ideas?