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.\" RCSid "$Id" |
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.TH OBJ2MESH 1 03/11/03 RADIANCE |
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.SH NAME |
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obj2mesh - create a compiled RADIANCE mesh file from Wavefront .OBJ input |
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.SH SYNOPSIS |
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.B obj2mesh |
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[ |
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.B "\-n objlim" |
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][ |
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.B "\-r maxres" |
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][ |
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.B \-w |
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] |
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[ |
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.B "input.obj" |
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[ |
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.B "output.rtm" |
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] |
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] |
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.SH DESCRIPTION |
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.I Obj2mesh |
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reads a Wavefront .OBJ file from |
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.I input.obj |
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(or the standard input) and compiles it into a RADIANCE triangle mesh, |
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which is sent to |
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.I output.rtm |
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(or standard output). |
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This mesh may be included in a RADIANCE scene description via the |
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.I mesh |
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primitive, thus: |
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.IP "" .2i |
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mod mesh id |
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.br |
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1+ output.rtm [xform args] |
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.br |
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0 |
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.br |
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0 |
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.PP |
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The syntax and semantics are nearly identical to the RADIANCE |
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.I instance |
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primitive, except that the mesh modifier may not be "void", since |
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materials are not included in a compiled mesh file. |
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.PP |
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The |
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.I \-n |
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option specifies the maximum surface set size for |
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each voxel. |
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Larger numbers result in quicker mesh generation needing |
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less memory, but potentially slower rendering. |
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Smaller values may produce faster renderings, |
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since the default number (15) is on the high side to reduce |
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the compiled mesh octree size. |
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Values below 6 are not recommended, since the median |
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valence (number of adjacent faces) for a mesh vertex is 6, |
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and smaller limits will result in pointless octree subdivision. |
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.PP |
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The |
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.I \-r |
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option specifies the maximum octree resolution. |
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This should be greater than or equal to the ratio of the mesh bounding |
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box to the smallest triangle. |
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The default is 16384. |
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.PP |
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The |
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.I \-w |
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option suppresses warnings. |
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.PP |
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Although the mesh file format is binary, it is meant to be portable |
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between machines. |
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The only limitation is that machines with radically different integer |
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sizes will not work together. |
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.SH DIAGNOSTICS |
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There are four basic error types reported by obj2mesh: |
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.IP |
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warning - a non-fatal input-related error |
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.IP |
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fatal - an unrecoverable input-related error |
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.IP |
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system - a system-related error |
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.IP |
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internal - a fatal error related to program limitations |
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.IP |
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consistency - a program-caused error |
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.PP |
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Most errors are self-explanatory. |
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However, the following internal errors should be mentioned: |
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.IP "Set overflow in addobject (id)" |
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This error occurs when too many surfaces are close together in a |
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scene. |
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Sometimes a dense mesh can be accomodated by increasing |
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the maximum resolution (by powers of two) using the |
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.I \-r |
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option, but usually this error indicates something is wrong. |
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Either too many surfaces are lying right on top of each other, |
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or the bounding cube is inflated from disparate geometry |
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in the input. |
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Chances are, the face number "id" is near |
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those causing the problem. |
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.IP "Hash table overflow in fullnode" |
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This error is caused by too many surfaces, and there is |
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little hope of compiling this mesh. |
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.SH EXAMPLE |
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To create a compiled triangle mesh from the scene file mesh.obj: |
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.IP "" .2i |
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oconv mesh.obj mesh.rtm |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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gensurf(1), getinfo(1), make(1), |
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oconv(1), rpict(1), rview(1), rtrace(1), xform(1) |
