Rendering stl file problem

Support Lighting and Rendering
1

Hello,
I recently started using Blender and so far really like the program. But I have one problem I cannot figure out. When working with stl files from PTC Creo and applying some specific steel material (http://matrep.parastudios.de/index.php?action=view&material=712-steel-polished&fc=2), all of the triangles of the stl file seem to be rendered individually. I tried reading about smooth shading and was looking for similar problems but could not find any. Honestly, I do not know what to look for exactly. The only solution I could find so far, was to apply a remesh modifier with Octree Depth 8. Then all looks well, but I have way to many faces then. Maybe the problem is related to the normals of the triangles? I attached the blend file and two screenshots and would be greatful to anyone who can point me into the right direction. Is it generally bad to use stl files? Should I export something else from CAD? Or is there some option in the material that is causing this problem?

steel_part.png1924×1200 349 KB

steel_part_rendered.jpg1924×1200 649 KB


Thanks for your help!
Greetings,
krosstoph

Attachments

steel_part.blend (1.19 MB)

2

The material is using “Tangent Shading”, which AFAIK depends on the object’s UV coordinates - unfortunately the object is not UV unwrapped at all. The bump map is set to use those non-existant UV coordinates as well, btw. In addition to that the mesh has unapplied scale and rotation.

What might help:
a) Set shading to “Smooth” and add an Edge Split modifier.
b) Hit Ctrl-A > Rotation and Scale to apply both to the mesh.
c) Hit Tab to enter Edit mode, A to select all and then U > Cube Projection to create quick and dirty UV coordinates.

What will certainly help:
Use Cycles…:wink:

Very quick Cycles material/lighting setup:

upload.png965×850 434 KB

3

Thank you very much, appreciate it :slight_smile: