Bryce can import 3D Autocad (DXF) files. Flat, Two-dimensional DXF files cannot be imported into Bryce. Many illustration applications can export DXF files, but these are in fact two-dimensional files and cannot be understood by Bryce.
Bryce 7 Pro imports several other file imports:
3D Studio Object Files .3DS
3D Studio Project Files .prj
3DMF (ASCII) Files .t3d
3DMF (Binary) Files .3mf
3DMF (Binary) Files .b3d
AutoCAD DXF Files .dxf
Direct3D Files .x (Windows only)
FBX SDK Import .fbx
FBX SDK Import COLLADA .dae
LightWave Object Files .lwo
LightWave Scene Files .lws
PGM Files .pgm
RayShade HF Files .hf
SketchUp Files .dae
Test Files .tst
TrueSpace Object Files .cob
TrueSpace Scene Files .scn
USGS DEM/SDTS Files .ddf
USGS/VistaPro DEM Files .dem
VideoScape Files .vsa
VRML 1.0 Files .wrl
Wavefront OBJ Files .obj
WCS Elev Files .elev
WorldToolKit NFF Files .nff