Selecting specific parts of an OBJ in Max?

[RyanSpaulding]

Hey guys,

 

I gave up on the DWGLink from MicroStation to Max for now...experimenting with other workflows. One is I can export OBJs from MicroStation and they retain their positioning on import.

 

So, I've been working with Modo lately and it allows you to select the OBJ by color (actually, Modo converts the colors to materials on import, so you can edit the material there...Max doesn't seem to create materials out of my level colors).

 

Is there a similar way to select specific section of an OBJ? Thus, I could apply a material to only that section. Furthermore, can I delete specific sections in case of edits by the architect? Or can I not delete from an OBJ in Max?

 

Help greatly appreciated.

[Chad Warner]

Once the obj is in Max, you could use edit mesh or edit poly to remove or select specific sections.

[Mechadus]

Im not terribly well versed with the .OBJ file format, but I have used them a few times between various packages.... usually Lightwave to Max... Since Modo is extremely similar to Lightwave, I hope it works the same way. Anyway, what I have found when importing a textured object into MAX is that it will usually assign material IDs to the polygons that have textures applied to them in other packages. You can use an Edit Mesh modifier (Or edit poly) to select the polygons by the material ID, and then either re-surface them from there using a multi-sub-object material, or break the mesh apart into separate objects. One big bonus is that it will maintain UV coordinates in most cases.

 

Hope that helps

 

-Nick

[RyanSpaulding]

Thanks guys.

 

So what of UVMapping then? If I have 1 mesh, how do I apply UVs to the specific sections so that I can control the map size?

[Chad Warner]

Do the UVW mapping while still having the individual faces selected. If all you are going to do is UVW map and not delete the faces, you'd want to use "mesh select." Basically, select the faces, apply to UVW modifier (which will only apply to the selected faces), then add another mesh select modifier on top of the UVW, select the faces, apply another UVW modifier, and so on.

[RyanSpaulding]

Hey Chad,

 

Hate to keep bugging you...just one more quick q.

 

Is there a way to save this selection...say I want to give one part of the model brick, and then I go onto the next texture, and so on. Say I want to go back and give that 1st brick displacement...I'd have to give that selection a vraydisplace mod, correct?

 

Will this cause any sort of conflict? Or is there an easy way to get that selection set recalled for later use?

[Chad Warner]

I don't think that the vray displace modifier works on selected faces. What you'd have to do is make a multi-sub object material and use a vray material for the brick, and put the displacement map in the material slot, but I'm not sure of the parameters when using the displacement map as part of the vraymaterial.

 

As far as keeping the selection set, when you move back down in the stack and select each "mesh select" it will highlight the faces that you selected at that point.

[RyanSpaulding]

Excellent. Thanks a ton.