Alright, some more details. I'm converting some constructive geometry models from BRL-CAD into faceted models in OBJ format. I'm converting them "region" by "region" in a constructive geometry sense. Each "region" becomes a "group" in an OBJ file sense.
Now, each region has a material value associated with it, typically an integer value that could represent things like: concrete, glass, tile, etc... to me it's just an integer. The important thing is that this material value be maintained as part of the usemtl label for the converted group. A list of these material values in maintained in a material .mtl file. The process I'm using (that unfortunately I can't change) dumps out a material file and obj file for each region converted. That part is just peachy the material file looks right, the obj file looks right as far as the mtllib and usemtl labels go they match the .mtl file. Great. Now the goal is to merge all these .obj files together into ONE .obj file and maintain the respective usemtl labels because in the analysis tool I've built (in Delta3D using OSG) I have the ability to change the color scheme or shading of the input OBJ model based on these usemtl or material values. I.e. the converted model might be a car and I might want to shade all the glass components "black" or all the plastic components "brown" etc.... I've already got the ability to do all of this as long as the OBJ file has proper usemtl labels (i.e. I edit the converted OBJ file by hand). So my question is there a way to merge these .obj files and maintain the group names, usemtl labels? I hoped to avoid writing my own OBJ parser just to accomplish this, but if I have no choice I'll guess I'll have to. I want to be able to take that correctly merged .obj file and use it in other analysis tools that read in this .obj file and the tool knows, based on the usemtl statements what kinds of materials this model is made of and then does some calculations that are not important to this issue... I'm mainly wondering are there other, specific arguments to readNode or writeNode (osgDB for the OBJ Plugin) that allow the maintaining of these labels? Like I said before the resultant, merged obj file had the correctly defined vertices and facets but the group names, usemtl labels are all auto generated, I think based on the input file name. Please let me know if you need any more information. Thanks in advance! Rob ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=12104#12104 _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
