Polygon UV map & Bump Map issues

[alloway]

I have a two part question regarding a polygon airplane I’m making.

What is the recommended procedure for creating a UV map of something that in real life is one object (e.g. the airplane), but in reality is composed of several parts (fuselage, rudder, elevators, etc.). I would like to create a single UV map for all the pieces since that would make painting the model easiest. Am I heading the right direction or should I create a separate UV map for each piece?

My second question regards bump maps. I was hoping to use bump maps for small details like panel lines and rivets, but they render poorly - they’re not crisp and have jagged edges. What is the most likely cause of jagged lines in a bump map? Should I be looking at render settings, bump map file size, lighting, something else?

Thanks

Mark

[Jak_Carver]

you can make a single object with one uv set if you want, but then you have to squeeze all your detail into one map, which means you'll have to use a very highres texture. Why not just seperate important pieces and give them their own materials and uv maps?

[alloway]

I thought putting them all on one map would make it easier to align things like camouflage, insignia, weathering, etc. I also thought it would make it easier to keep the resolution for each piece in scale (I’m assuming the image size for the ailerons should be significantly smaller than the image size for the fuselage). Are these assumptions incorrect?

If putting them all on one map isn’t the way to go, then I’m okay with that. I’m new to this and I’m trying to avoid developing bad workflow habits.

Thanks for your reply.

Mark

[Yeoman742]

You must be very careful if you are using UV and bump maps seperately rather than one big highres. The reason I found though my own personal experience happens that if you use say 1048 size graphic, each piece you map will stretch to fit that 1024, and the area of a wing is bigger than that of the rudder. You end up with fine detail on the rudder and a more course texture on the wing. I hope I've made myself understandable, I've provided an expample.

http://i6.photobucket.com/albums/y205/Yeoman742/close-up.jpg

[alloway]

I suspected something like that would happen, but I thought I could get around it by doing something like this:

·Do a planar projection of the aircraft from the top (the biggest profile)

·Record it’s projectionHeight value

·UV map the individual parts using the projectionHeight value of the whole model to keep the various components in scale (small_part.projectionHeight / whole_object.projectionHeight = corrected projection size)

I think this should give me the correct U/V proportions within the UV texture space. I was just hoping to avoid the extra work.

[McGergs]

It really depends on what you want to use it for. If you want it to be in a game then yes one UV map.

Personally I would do seperate UV maps. If you want it to look nice and very realistic, this is the way to go.

For example the fuselage would be one UV map.

Since the plane is most likely sysmetrical UV map one wing and the duplicate. That is unless they have writting on them then you would have to UV then duplicate then move the UV corrdinates for the new one to a new spot.

[alloway]

Thank you.