ACIS to 3DS
3 messages in this thread
I am having a problem with the export of ACIS solids from ACAD R13c1 to 3DS
R4c1. The rendered objects have problems with face normals and smoothing. I am
using the default settings in R13.
Hi Tom,
I haven't worked with the ACIS stuff form ACAD, but have heard that weird
results can occur. If you can get a model into 3DS, work with
Surface/Normals/Object Unify, and Surface/Smoothing/Object/Auto Smooth. If
you've tried that and it still doesn't look right, please describe what you're
model is doing in more detail.
Another option is the Optimize ipas routine from the Yost Group. It's on disk
7. This will let you do more manipulation of Normals and Smoothing groups.
I hope this helps,
Bruce
Tom,
Another problem that can occur is mesh mismatches where various surfaces meet
up. If you are building 3D objects from multiple surfaces/volumes, when
AutoCAD converts the volumes to mesh surfaces it often doesn't check that
adjacent surfaces have matching vertices. This is a common problem on things
like ball-fillets. AutoCAD treats each edge fillet and the corner ball fillet
as separate surfaces. When it meshes them you can get "T" intersections
instead of the proper "X" intersections between meshes. The result is dark
streaks on smooth surfaces. This can also confuse 3DS when it has to calculate
surface normals for things like object-unify and boolean operations.
Terry Gilbert
Forcade & Associates