Hello,

In exporting a Blender mode, by checking use_smooth, the smooth effect can be exported, using:

Code:

if face.use_smooth:                             # use vertex normal (full smooth effect)                         else:                             # use face normal (no smooth effect)

However, like in the 3D view port, the effect seems binary: I have all or none smooth effect.

Is there a way to use the auto_smooth option (use_auto_smooth in python) and the related angle (auto_smooth_angle in python) to set some more precise smooth effect in the export?
From reading the 2 values, I should recompute the vertex normals?

Thanks in advance for your help.

In the above "code", the normals are applied to the exported vertex being porcessed.

I found some interesting code on this matter (trainz exporter):

Code:

def get_autosmooth_normal(mesh, fop, mesh_vi):  '''check if smoothing has to be applied and return the depending normal''' ##  is at least one neighbourface smooth, the we return the vertex ##  normal(smooth applied), else the face normal will be returned     result = fop.normal  # init with the normal for the un-smooth case     ##  faulty (none-planar) faces may have a zero-length normal, and without     ##  direction you can't calculate direction difference     if fop.normal.length > 0.0:       for p in mesh.polygons:          if ( p != fop ) and ( mesh_vi in p.vertices ) and ( p.normal.length > 0.0):             angle = int(round(math.degrees(fop.normal.angle(p.normal))))             if  angle <= mesh.auto_smooth_angle:                result = mesh.vertices[mesh_vi].normal     return result     -------------------    if face.use_smooth:       if mesh.use_auto_smooth:          no = mathutils.Vector(obj_prop[OBJ.ROT] * get_autosmooth_normal(mesh, face, face.vertices[face_vi]))       else:          no = mathutils.Vector(obj_prop[OBJ.ROT] * mesh.vertices[face.vertices[face_vi]].normal)    else:       no = mathutils.Vector(obj_prop[OBJ.ROT] * face.normal)

I found 2 problems in the above code :
1) for p in mesh.polygons should be replaced by for p in mesh.tessfaces:
2) mesh.auto_smooth_angle is in radians. Thus angle has to be computed as:
angle = fop.normal.angle(p.normal)