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View Full Version : Multiple UV tiles for displacing a single object...



Gregg "T.Rex"
04-08-2009, 08:02 AM
My brain is fried (again), so can someone remind me how to set up the displacement node editor to use multiple images with multiple UV tiles, all affecting a single continuous object?

Like when you have a single SubD object, which has a single UV map, but with multiple UV tiles inside...

Thanks,
T.Rex

jasonwestmas
04-08-2009, 08:20 AM
Scalar Add the different nodes together or layer stack them in a layer node? What kind of nodes are you using?

Gregg "T.Rex"
04-08-2009, 08:39 AM
Scalar Add the different nodes together or layer stack them in a layer node? What kind of nodes are you using?

Here's a screen shot of what i want to do; i'm testing the possibilities on a cylinder object:

http://www.sub-pixel.com/DispScreen.jpg

I need a way to tell to each Image node, which UV tile to use, from the single UV file i have; which obviously have multiple UV tiles...

For surfacing it's easy to do, as we can separate the model in different surfaces, but for displacement we can only have a single mesh to apply the displacement...

I could provide the mesh if needed, as this is a test scene to see if multiple UV tiles work indeed with LW, though the four disp maps are a 220MB zip file all together...

Thanks,
T.Rex

jasonwestmas
04-08-2009, 08:55 AM
Well this may solve one problem. If you simply copy your UV map several times in modeler and rename each one; then apply each of those newly created maps to each different image node; that would eliminate the blimpy kind of look you get if you added all the images to the same UV map.

If you attach the scene and object I'll take a look.

Gregg "T.Rex"
04-08-2009, 08:56 AM
ok, let me try that and i'll resize a bit the disp maps to make the file size smaller and then post the scene here...

Gregg "T.Rex"
04-08-2009, 09:44 AM
Well this may solve one problem. If you simply copy your UV map several times in modeler and rename each one; then apply each of those newly created maps to each different image node; that would eliminate the blimpy kind of look you get if you added all the images to the same UV map.

If you attach the scene and object I'll take a look.
Well...
That did work, but it produces seems on the edge where each map meet the other...
I'm uploading the scene right now for evaluation; a 22MB zip file...

There is a possibility that these seems could be eliminated if the UV tiles have more space in between them, according to Mudbox; i'll check that as well, though i'm afraid won't do any good, as i believe it's LightWave that can't handle correctly multiple UV tiles, because those UV tiles already have some space in between them; we'll see...

Anyway, here's the link to download the test scene: Multiple UVs (http://www.sub-pixel.com/MultipleUVs.zip)
Just unzip it somewhere, set the content to that folder and load the scene....

Thanks,
T.Rex

jasonwestmas
04-08-2009, 10:26 AM
I guess I'm a little confused on what you are intending the displacement to look like. :) Originally I thought you were just trying to add the displacements together but it looks to me now that you want to have one displacement per UV island transition into another UV island displacement. Is that correct? So if the Texture is tileable it should work between identical UV maps. I noticed that you removed parts of your UV's for each UV map. I meant to clone your base texture and have the same UV's for each map I don't see any seams when I do that. I would experiment with something that is a little less organic I guess.

jasonwestmas
04-08-2009, 10:34 AM
So why does this need to be tileable. I'm curious about what you are trying to tile. Should be an easier way.

jasonwestmas
04-08-2009, 10:42 AM
So if you did want to tile/transition between different displacement maps that were tileable you would need each UV map to be identical I would think, otherwise seams are inevitable.

Gregg "T.Rex"
04-08-2009, 10:42 AM
So why does this need to be tileable. I'm curious about what you are trying to tile. Should be an easier way.

This is a test object to see if the "Multiple UV tile" thing work with LightWave's displacement. The need to tile the UVs is simple because Mudbox can bake seamlessly the sculpt/paint work you do, on multiple images each using the corresponded UV tile. The benefit for this is that you can have extremely high rez for your textures, since you end up with multiple 4K images containing the disp and paint information, instead of one 4K image...

Here's how this cylinder looks in Mudbox, before exporting...

http://www.sub-pixel.com/Mudbox.jpg

Cheers,
T.Rex

sammael
04-08-2009, 11:27 AM
Not positive but tou should be able to do this with a colour layer node containing your images mapped to whichever uv's you specify. Making the maps on the stack additive should blend them together, then its a matter of playing with the opacity of each.

Should work in theory...

Gregg "T.Rex"
04-08-2009, 11:32 AM
Not positive but tou should be able to do this with a colour layer node containing your images mapped to whichever uv's you specify. Making the maps on the stack additive should blend them together, then its a matter of playing with the opacity of each.

Should work in theory...
The problem is not to stack the displacement images together...
The problem is to apply them on the same object using a single UV map, but one that has multiple UV tiles and have each image use a given UV tile...

Gregg "T.Rex"
04-08-2009, 11:34 AM
I updated the scene file, with something easier to see...

Multiple UV Tiles (http://www.sub-pixel.com/MultipleUVs.rar)

This time is a 14MB RAR file...

I can't get rid of the seems now...

Gregg "T.Rex"
04-08-2009, 11:50 AM
Here's some useful info taken from Mudbox's manual:

UVs can be positioned outside of the default 0 to 1 UV range (provided your rendering application supports this) which helps to ensure that parts of the model requiring higher detail in an image, can take advantage of the resolution (pixels) it provides compared to having all of the UVs in one tile.

If the UVs are laid out so they use multiple UV tiles you'll be able to take advantage of multiple high resolution painted maps and obtain much more detail on your models as a result.

Multiple UV tiles are also useful when extracting normal or displacement maps from a high resolution sculpted model as the sculpted detail can be captured more effectively using multiple high resolution images than would otherwise occur with a single extracted map.

Only thing to find out is IF LightWave's node editor can support properly this option... :)

Cheers,
T.Rex

jasonwestmas
04-08-2009, 12:23 PM
Ok, I better understand now Greg, thanks. I'll look into it a bit later.

Gregg "T.Rex"
04-08-2009, 12:28 PM
Ok, I better understand now Greg, thanks. I'll look into it a bit later.
No, thank you...
I still can't figure out a way to do this...
I can "hack" it using weight maps to isolate the edges, but it's not acceptable as instead of spikes on the edges, i get no displacement at all...

I really hope that Multiple UV tiles are indeed supported by LightWave's architecture somehow and i'm only missing it, or else this would be a real show stopper for the upcoming project i have to do...

sammael
04-08-2009, 12:55 PM
Forgive me if I'm still missing something?

sammael
04-08-2009, 01:10 PM
ahh no sorry I see the problem...
although I cant see the problem with setting it up that way instead?

sammael
04-08-2009, 01:36 PM
if its essential to have it in the one uv map it looks like you might be able to do something with the u and v offset imputs of the image nodes... otherwise splitting it into seperate uvs like that is probably easier.

Gregg "T.Rex"
04-08-2009, 02:45 PM
Sometimes the solution is so simple and right under your nose, you won't see it... :)

Of course, it would be better if LightWave could handle the multiple UV tiles natively using only one UV map, nevertheless using the setup attached, (Thanks goes to Sammael!), seams that it does the trick well. We still need a different UV name per tile, but that's not a problem, as they are easily extracted from the main UV map...

It seems that this way the displacements work okay and in a similar manner we can have multiple surface names of the same surface, one for each UV tile, to use for other maps, like color, diffuse etc...

So, i think we have a solution here...

T.Rex

jasonwestmas
04-08-2009, 03:19 PM
Ah, that's great! I didn't realize that the separate UV maps actually filters out each displacement image individually like that. Very neat!

sammael
04-08-2009, 09:09 PM
Glad it works.
Its cool that mudbox will allow you to do that, do you know if zbrush will handle it as well? Sometimes being limited to a 4096 map really buggs me.

jasonwestmas
04-09-2009, 04:44 AM
As far as I know ZB or multi-displacement 3 cannot do that, I've never used Mudbox so I wasn't familar with this technique at all. I only knew that I have to use separate UVs maps when combining Displacement files. However there is this tutorial:

http://www.zbrushcentral.com/zbc/showthread.php?t=61676&highlight=Tiling

The work around is to just use subtools and then sculpt across the subtools. You then export from each sub tool a separate displacement map.

Kuzey
04-09-2009, 05:52 AM
This is quite interesting...well done guys :thumbsup:

Kuzey

yolao
09-06-2010, 12:46 PM
We still need a different UV name per tile, but that's not a problem, as they are easily extracted from the main UV map...


Hi

I try to set a polygon mesh with 5 diferent uv tiles in diferent uv space. But i dont know how to set the U and V offset of each map.
So maybe asign each map to a diferent uv map...but the whole mesh has just one uv map...which has the diferent uv tiles...

How do you extract diferent uv maps from the main maps to put them other names..?

Thanks

jasonwestmas
09-06-2010, 01:31 PM
Hi


How do you extract diferent uv maps from the main maps to put them other names..?



You can copy UV maps in modeler, rename them and simply clear the polys you no longer want in the UV map. So if you have two UV maps that are copies of the original map, select the polys/UV you don't want in the UV map and clear them out under the map tab.

Of course this is greatly dependent upon how your texture bitmap islands are constructed and line up with the UVs.

Gregg "T.Rex"
09-06-2010, 05:00 PM
Hi

I try to set a polygon mesh with 5 different uv tiles in different uv space. But i don't know how to set the U and V offset of each map.
So maybe assign each map to a different uv map...but the whole mesh has just one uv map...which has the different uv tiles...

How do you extract different uv maps from the main maps to put them other names..?

Thanks

No need to create multiple UV maps; wouldn't work this way either, if i've understand correctly what you want to do...

Basically, all you need to figure out is what's the offset of each UV tile, or in other words, how many tiles away from 0 you've laid out your UV tiles. Maybe the image below can help on how to assign multiple images using a single multi-spaced UV map.
Click on the image for full size:
http://www.sub-pixel.com/tmp/Screen0_t.jpg (http://www.sub-pixel.com/tmp/Screen0.jpg)

That is, if that's what you asked at first place... :)

Cheers,
T.Rex

Gregg "T.Rex"
09-06-2010, 05:08 PM
BTW, the above setup works for displacement as well; gray-scaled height or colored vector...

yolao
09-08-2010, 10:25 AM
Thanks guys.

Gregg, many thanks for the screenshot, it works fantastic with no seams whatsoever!!

Cheers