Just a new alien ship
Moderator: pyramid
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
Just a new alien ship
Today while I was playing around in Blender, I got an idea for a ship. There's only one problem. I'm not sure if it will fit into any of VS lore. The ship already looks very alien and my plans for texturing it are for making it look even less like a human craft. Can anyone tell me if you need this ship?
Two renders with HDRI lighting
And a plain render:
Two renders with HDRI lighting
And a plain render:
There are no stupid people on Earth; they are only alternatively thinking.
-
- Elite
- Posts: 1671
- Joined: Fri Jan 03, 2003 12:46 am
- Location: Earth, Sol system.
- Contact:
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
Gorgeous! How do you get HDR lighting? Is this using the yaffray renderer?
(BTW, if Vegastrike don't want it, we have an opening for an alien ship in WCU's Privateer 3 storyline, which requires a Mantu ship. The Mantu are mentioned in WC canon, but never shown or described in detail.)
(BTW, if Vegastrike don't want it, we have an opening for an alien ship in WCU's Privateer 3 storyline, which requires a Mantu ship. The Mantu are mentioned in WC canon, but never shown or described in detail.)
Last edited by chuck_starchaser on Sat Feb 03, 2007 8:20 pm, edited 1 time in total.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
You got that right, I used Yafray for the render. Too bad it's not available yet for Blender Internal.
Chuck, I have some problems with the Texture Baker script. Every time I attempt to use it, it returns that the active object is not a mesh or has no UV coordinates. Although the Save UV Layout works fine.
Chuck, I have some problems with the Texture Baker script. Every time I attempt to use it, it returns that the active object is not a mesh or has no UV coordinates. Although the Save UV Layout works fine.
There are no stupid people on Earth; they are only alternatively thinking.
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
I was editing the previous post, check it out again.
I had the exact same problem you describe when I downloaded an unofficial version of Blender that was out of synch with the raybaker script. I used to have a link to an updated script that solved the problem. Which Blender version are you using?
I had the exact same problem you describe when I downloaded an unofficial version of Blender that was out of synch with the raybaker script. I used to have a link to an updated script that solved the problem. Which Blender version are you using?
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
That's very efficient; looks like a 3k poly model.
There are better scripts that do work. Go to the scripts window, and into the Image menu of scripts; try those.
There are better scripts that do work. Go to the scripts window, and into the Image menu of scripts; try those.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
Sure; post the file, or email it to me.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
I had no problem baking a texture; I used, from the scripts window,
Image -> Bake texture image from UV's
Try it, see if it works for you.
The UV layout is okay, pretty efficient. My only remarks would be:
a) you are re-using the islands for both sides of the ship. This is good and efficient, BUT, it won't work with Klauss' new shaders' Global Illumination (GI). So, the current guidelines are to have a one-to-one (no folding, no overlap) UV layout. Or, better yet, to have two UV layouts: One WITH folding and overlaps (like yours) and one without. Blender now handles multiple UV layouts, and so does Ogre, but I'm not sure whether Blenders Ogre-exporter handles them yet.
The UV layout without folding or overlaps will then be used for the PRT-P and PRT-N bakings (long story, needed for GI), normal mapping (I think), and static light map from self-illumination; wheras the UV layout that uses folding and sharing of UV islands is used for the diffuse and specular textures.
b) The layout is a bit TOO efficient: You need at least a few pixels of space between islands. The reason is that filtering, by the video card, specially anisotropic filtering, reads neighboring pixes, and begins to bleed color between neigboring islands as the viewing distance increases. The standard is to scale down the islands a tiny bit, so as to leave room between them. Once you have your texture done, you fill the unused space between the islands with a color that's somewhat of an average color for the whole texture, for starters. Then, in Gimp, you can use the tool to select contiguous regions by color to select all unused areas. With them selected, you do a gaussian blur, and you'll see the blur pass only modifies pixels in the selected areas, but reading pixels from across selection boundaries. What this does is it bleeds your textures out of the UV islands and into the background. Repeat the blur a good 5 to 10 times, so that when the filtering hardware in the videocard filters the edges of your texture islands and looks at neigboring, background pixels, it sees pretty much same colors. It will greatly diminish the artifacts.
c) You might want to re-orient the texture islands so that front of the ship is always to the left, say, and back to the right. What this will do for you is strategic: You could generate, for instance, micrometeorite impacts, or smoke/air marks that fade towards the back of the ship, by, in Gimp, starting with a random snow and blurring it to the right. You can then pretty much apply that to the entire texture. Otherwise you have to rotate such effects to match the angle the pieces make to the front-back direction...
Image -> Bake texture image from UV's
Try it, see if it works for you.
The UV layout is okay, pretty efficient. My only remarks would be:
a) you are re-using the islands for both sides of the ship. This is good and efficient, BUT, it won't work with Klauss' new shaders' Global Illumination (GI). So, the current guidelines are to have a one-to-one (no folding, no overlap) UV layout. Or, better yet, to have two UV layouts: One WITH folding and overlaps (like yours) and one without. Blender now handles multiple UV layouts, and so does Ogre, but I'm not sure whether Blenders Ogre-exporter handles them yet.
The UV layout without folding or overlaps will then be used for the PRT-P and PRT-N bakings (long story, needed for GI), normal mapping (I think), and static light map from self-illumination; wheras the UV layout that uses folding and sharing of UV islands is used for the diffuse and specular textures.
b) The layout is a bit TOO efficient: You need at least a few pixels of space between islands. The reason is that filtering, by the video card, specially anisotropic filtering, reads neighboring pixes, and begins to bleed color between neigboring islands as the viewing distance increases. The standard is to scale down the islands a tiny bit, so as to leave room between them. Once you have your texture done, you fill the unused space between the islands with a color that's somewhat of an average color for the whole texture, for starters. Then, in Gimp, you can use the tool to select contiguous regions by color to select all unused areas. With them selected, you do a gaussian blur, and you'll see the blur pass only modifies pixels in the selected areas, but reading pixels from across selection boundaries. What this does is it bleeds your textures out of the UV islands and into the background. Repeat the blur a good 5 to 10 times, so that when the filtering hardware in the videocard filters the edges of your texture islands and looks at neigboring, background pixels, it sees pretty much same colors. It will greatly diminish the artifacts.
c) You might want to re-orient the texture islands so that front of the ship is always to the left, say, and back to the right. What this will do for you is strategic: You could generate, for instance, micrometeorite impacts, or smoke/air marks that fade towards the back of the ship, by, in Gimp, starting with a random snow and blurring it to the right. You can then pretty much apply that to the entire texture. Otherwise you have to rotate such effects to match the angle the pieces make to the front-back direction...
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
Thanks for your help, Chuck. I totally forgot about the alignment, though I read that in your previous work (probably with Hornet). I'll start with the non-overlapping UV map tomorrow - my sister wants to sleep and I have to share a room with her .
There are no stupid people on Earth; they are only alternatively thinking.
-
- Minister of Information
- Posts: 1895
- Joined: Fri Jan 31, 2003 9:40 pm
- Location: The land of tenure (and diaper changes)
-
- Elite
- Posts: 7243
- Joined: Mon Apr 18, 2005 2:40 pm
- Location: LS87, Buenos Aires, República Argentina
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
Great! I've posted a question at the WCU forum, about its suitability as a Mantu ship, just to make sure.
Indeed, this ship deserves more polys. There's something about Blenders' Smooth and Subdivide Smooth, though; they never work just right, at least for me (mesh edges pulled in, vertices moving in unexpected directions...).
Indeed, this ship deserves more polys. There's something about Blenders' Smooth and Subdivide Smooth, though; they never work just right, at least for me (mesh edges pulled in, vertices moving in unexpected directions...).
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
Yeah, that looks much better --smooth reflections. Yeah, I'd forgotten; Smooth never worked for me, but subsurf did.
Don't need to worry that much about poly count, IMO, Kangaroo; poly count was more of an issue two or three generations of videocards ago. Today's hard limit on performance is more the memory bandwidth, which is much more affected by the size of the textures than by the size of the mesh. The concern with poly count, IMO, is a klingon from days long gone.
Don't need to worry that much about poly count, IMO, Kangaroo; poly count was more of an issue two or three generations of videocards ago. Today's hard limit on performance is more the memory bandwidth, which is much more affected by the size of the textures than by the size of the mesh. The concern with poly count, IMO, is a klingon from days long gone.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Venturer
- Posts: 543
- Joined: Sun Jan 22, 2006 9:55 am
- Location: Baltic States
- Contact:
I believe the smooth tool blends the shape closer to a sphere(?)
Well, I don't know, my card is perhaps 6 years old? My computer's still running with acceptable performance because of it's motherboard's optimization with RAM and processor.
I guess I have to rally myself and start working on the non-overlapping UV map and redo the existing one.
Well, I don't know, my card is perhaps 6 years old? My computer's still running with acceptable performance because of it's motherboard's optimization with RAM and processor.
I guess I have to rally myself and start working on the non-overlapping UV map and redo the existing one.
There are no stupid people on Earth; they are only alternatively thinking.
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
It will be a good exercise. Once you got the two UV's I'll show you how to generate PRT-P and PRT-N bakings, maybe make a tutorial out of it. If you're up to it, could make a normal map baking. Dual Joe is the one that knows that well, though; wish he'd write a tutorial on that, but he's busy nowadays. Basically, creating a temporary model with a lot more subsurfing (~100k polys) and baking the difference between it and the regular mesh into a normal map.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Elite
- Posts: 7243
- Joined: Mon Apr 18, 2005 2:40 pm
- Location: LS87, Buenos Aires, República Argentina
Normalmapping isn't needed if all you'll do is subsurfing, though.
Only if you intend to then edit the subsurfed mesh it's worth it.
And... in many many cases (mostly for tiny greeble details), a normalmap derived from a old-fashioned bumpmap (gimp tools all over the place for that) is much easier to do, and more than enough.
Remember that per-pixel lighting shaders already smooth out the normals and such, so you get the same smooth appearance without normalmaps - normalmaps are for when the surface isn't smooth, or when it doesn't match the geometry, rather than for when it is.
Only if you intend to then edit the subsurfed mesh it's worth it.
And... in many many cases (mostly for tiny greeble details), a normalmap derived from a old-fashioned bumpmap (gimp tools all over the place for that) is much easier to do, and more than enough.
Remember that per-pixel lighting shaders already smooth out the normals and such, so you get the same smooth appearance without normalmaps - normalmaps are for when the surface isn't smooth, or when it doesn't match the geometry, rather than for when it is.
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
I've seen normal maps baked out of subsufs of pretty smooth surfaces, in the Ogre forum, and noticed they produced subtle --but definitely there-- normal map corrections. I think the subsurf algorithm used by Blender is a lot more sophisticated than linear normal interpolation done in the gpu; could be wrong.
As far as deriving a normal map from a bumpmap in Gimp, xNormal, for example, allows you to include a bumpmap with the geometry. Not sure if it would be better than Gimp; just mentioning it.
As far as deriving a normal map from a bumpmap in Gimp, xNormal, for example, allows you to include a bumpmap with the geometry. Not sure if it would be better than Gimp; just mentioning it.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Artisan Extraordinaire
- Posts: 1269
- Joined: Tue Mar 21, 2006 10:55 am
- Location: Philippines
Cool ship.
However i suggest to keep clear of automatic modifiers (like subsurfing, which i presume is the equivalent of 3dsmax's meshsmooth function) , they often give you speed at the expense of more polies than is actually needed. It doesn't give you much control (or any control at all) over the triangulation and stuff.
I know that doing something like this by hand is difficult and might be messy, but I suggest doing just that. Does blender support smoothing groups? Those can give nice smoothened surfaces with only a few polies.
However i suggest to keep clear of automatic modifiers (like subsurfing, which i presume is the equivalent of 3dsmax's meshsmooth function) , they often give you speed at the expense of more polies than is actually needed. It doesn't give you much control (or any control at all) over the triangulation and stuff.
I know that doing something like this by hand is difficult and might be messy, but I suggest doing just that. Does blender support smoothing groups? Those can give nice smoothened surfaces with only a few polies.
A Step Into Oblivion
Dreams of things that will never be,
Songs of thoughts only I can hear,
Leave me be to sleep forever,
To dream my dreams,
And sing my hymns,
Of things that will never be...
Dreams of things that will never be,
Songs of thoughts only I can hear,
Leave me be to sleep forever,
To dream my dreams,
And sing my hymns,
Of things that will never be...
-
- Elite
- Posts: 8014
- Joined: Fri Sep 05, 2003 4:03 am
- Location: Montreal
- Contact:
Oblivion, smooth groups give you nothing of the sort. A smooth group is a grouping of polygons that you split from the rest, in order to have them appear smooth shaded as a group, but with a sharp crease around them. Each of those (windows?) in Kangaroo's model is a smooth group.
http://vegastrike.sourceforge.net/wiki/ ... oth_Groups
Smooth grouping doesn't add detail, nor does it move any vertices. It's a totally different and unrelated concept.
In Blender, you designate a smooth group by highlighting the polygons you want to separate and pressing Y, for split. It splits (duplicates) the vertices surrounding the smooth group, allowing smooth shading on both sides of the split, but a sharp crease where the vertices are split.
Understanding smooth groups is very important in modelling. You want to use smooth shading and smooth groups in place of flat shading, in many cases, particularly large, flat surfaces, for performance reasons. Check this:
http://vegastrike.sourceforge.net/wiki/HowTo:Bevel
Blender's subsurface feature works fairly well. Sometimes you have to manually fix vertices around the edges; but other than that it does a pretty good job.
http://vegastrike.sourceforge.net/wiki/ ... oth_Groups
Smooth grouping doesn't add detail, nor does it move any vertices. It's a totally different and unrelated concept.
In Blender, you designate a smooth group by highlighting the polygons you want to separate and pressing Y, for split. It splits (duplicates) the vertices surrounding the smooth group, allowing smooth shading on both sides of the split, but a sharp crease where the vertices are split.
Understanding smooth groups is very important in modelling. You want to use smooth shading and smooth groups in place of flat shading, in many cases, particularly large, flat surfaces, for performance reasons. Check this:
http://vegastrike.sourceforge.net/wiki/HowTo:Bevel
Blender's subsurface feature works fairly well. Sometimes you have to manually fix vertices around the edges; but other than that it does a pretty good job.
Latest version of Cinemut Opaque
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
Latest version of LaGrande noodleworks (scroll down).
An evolving La Grande How-To...
The non-working, but latest, CineMut test_bike
PU (Privateer: Parallel Universe's Home). WC or Privateer Drayman for you?
WCpedia --The Wing Commander Encyclopedia-- From Angel Deveraux through Belisarius to Zachary Banfeld...
WC Nexus forum, the Moonbase Tycho of WC fans.
-
- Elite
- Posts: 7243
- Joined: Mon Apr 18, 2005 2:40 pm
- Location: LS87, Buenos Aires, República Argentina
I see. Makes sense.chuck_starchaser wrote:I've seen normal maps baked out of subsufs of pretty smooth surfaces, in the Ogre forum, and noticed they produced subtle --but definitely there-- normal map corrections. I think the subsurf algorithm used by Blender is a lot more sophisticated than linear normal interpolation done in the gpu; could be wrong.
Still, I wouldn't use a NM on that case.
Think of the overhead, both at production and runtime.
At runtime, the increased memory bandwidth, not only from the NM itself but also other maps that might need now a non-overlapping unwrap (though a separate coordinate set might mitigate that second issue). Plus increased shader complexity.
At production time, the work need to bake a NM isn't negligible, and if it's the only reason to produce a non-overlapping unwrapping worse. Perhaps a quick LSCM would work, but still.
Unless they're big differences in quality, which I doubt can't be accomplished with some clever beveling at selected places, I doubt it's justifiable.