Can't read obj_info header written by CloudCompare

[rreusser]

Thanks for the great parser! We were so happy to find it. ❤️😄🌈🎉

One issue we ran into: CloudCompare writes a obj_info header, e.g.

ply
format ascii 1.0
comment Created by CloudCompare v2.10.2 (Zephyrus)
comment Created 8/1/19 9:04 AM
obj_info Generated by CloudCompare!
element vertex 4308
property float x
property float y
property float z
element face 8612
property list uchar int vertex_indices
end_header
74.5034 161.291 168.961 
77.047 149.808 164.128 
73.8367 161.097 169.151 
73.1975 160.869 169.417 
...

I can ping someone to track down the exact line of code that's failing, but it seems pretty cut and dry that you simply have to remove the obj_info line to avoid getting an error about an invalid header. Seems like just a simple obscure PLY header field that's not handled.

We'll probably have to fix this, but at the very least wanted to get it reported. Thanks again!

See also: PointCloudLibrary/pcl#2763 (comment)

[rreusser]

For a start, maybe just detect it and skip it?

happly/happly.h

Lines 1485 to 1491 in 826c5ab

	// Parse a comment
	if (startsWith(line, "comment")) {
	string comment = line.substr(7);
	if (verbose) cout << " - Comment: " << comment << endl;
	comments.push_back(comment);
	continue;
	}

Or store as a comment? (Or create a proper data structure for obj_info, but maybe that's overkill for how common/meaningful it is?)

[nmwsharp]

Glad hapPLY is useful for you!

Yeah, obj_info seems to be common enough that we should definitely accept files which include it...

Easy solution would be to skip such lines, but it seems a nonzero number of users pack important info in to it (see e.g. here), so it's probably worthwhile to preserve. I'm thinking just dump all obj_info lines in to a std::vector<std::string>>.

It looks like the recent pull db040e7 already added something to handle this, so I'll work a fix in with that soon.

[nmwsharp]

This should be fixed as of f196c50. obj_info lines are now treated like comments-- they can be both read and written to. Please reopen if anything doesn't seem right!

[rreusser]

Thanks so much, @nmwsharp! Your quick response and fix are really, really appreciated! 🎉