wrinkly dragon

[devilbunny]

Here's a model I've been working on for a while. I'm pleased with it so far, though it needs more work on the face, and some eyes. Having a strange problem with normal maps though, when I bring it into 3ds max.

zbrush_dragon_051205a.jpg

Let's see, I believe I used AUV texture mapping, all the maps are 4096*4096. When I create the normal map, I get an obvious crease along the neck. There is no edge loop there, or polygroup edge, and I have clicked the Fix Seam button (with the default FSBorder setting of 4) several times. Here's the normal map in ZBrush:

zbrush_dragon_051205b.jpg

And here it is in 3ds max 7, with the scanline renderer. I exported the mesh from ZBrush as an OBJ at Subdiv 1, with the default export settings. I exported the normal map from ZBrush as a TIFF (4096*4096). In max, I applied the normal map to the Normal Bump channel, flipped the Y Axis, and set Blur to 0.01.

zbrush_dragon_051205c.jpg

Any suggestions would be appreciated, thanks!

[Moochie]

Can't help with your mapping problem, but just wanted to say "Cool model!" :tu:

[Poly pusher]

Nice model, looks to me like its a problem with the UV's. Have you tried to project the normal map in Max rather than ZB, just to see if the same thing happens?

[devilbunny]

Thanks for the nice words.

I think the UVs are alright. The texture map and displacement maps apply just fine in max. I have tried to make the normal map in max, and it doesn't have a problem with that area.

[Poly pusher]

Well, that is odd. I don't know what to suggest. I guess any time I see a seam like this I think UV's, but hey keep us posted as you figure it out, I am also doing some normal map work right now, and would be very interested in how you solve this problem.

Thanks

[Drummer]

very nice work!
about your problem, I still never try to generate a normal map, but maybe it is like a displacement map. it is not very long ago I have solved my displacement problems.......but your trouble is in ZB too, from what I can see...

try to create a GUV before doing everythings, and not a AUV, I have had a lot of troubles with it !!
I know that Aurick says to click fix seam everytimes, for the texture map he is right, but for example about displacement, "fix seam or not fix seam" is the same thing !

I hope to be helpful

:cool: :tu:

[devilbunny]

If I figure this out, I will certainly share the tip, but so far no luck.

I tried creating a new 4096*4096 texture, and applying GUV Tiling with an AUV Ratio of 1, to keep things simple. I then re-created my Normal Map, but with the same results. I also tried AUV Tiling, with the same Ratio, same results. If I go up to Subdiv 3, delete the lower Subdiv levels, and re-create the Normal Map, then the seam is less noticeable, but of course starting with such a high-poly base mesh kind of defeats the purpose of normal maps.

I must be doing something stupid here, but I can't figure out what.

[Poly pusher]

Did you try using 'cage' to reconstruct the lowest sub-d level mesh, to better match the higher sub-d mesh's detail? Or have you tried UV smoothing? I can only think to play around with those things.

[Drummer]

I agree with Poly Pusher, and I think if the problem persists, the only probable thing is that there is a problem with your model..... strange thing....the solution for me, in some problematic works, is to re-model your tool from the lowest subdivision and try more and more while the result is how you want.

I hope you get over, friend.
good luck
:cool: :tu:

[devilbunny]

Thanks for the ideas. If by "UV Smoothing", you mean turning on that option when I create the Normal Map in ZBrush, yes I've been doing that.

I tried recreating the SubDiv cage, I hope this is the correct procedure:

1. Go to SubDiv 7, Delete Lower Res. SubDiv 7 now becomes SubDiv 1.
2. Click Reconstruct Subdiv. Go to new SubDiv 1, turn on Cage.

I repeated step 2 until I had 5 SubDiv levels, turning on Cage each time before reconstructing. SubDiv 1 now has 6,016 polys, so I created a new Normal Map, 4096*4096, Tangent, Adaptive and SmoothUV all turned on, and as you can see, I still have a seam in the same place:

http://anvil-studio.com/images/zbrush_dragon_051205d.jpg

The only other way I know to check the mesh for errors is to bring it into 3ds max and apply an STL modifier (checks for open edges, double faces, spikes, and multiple edges). The only thing it found was the open neck. That couldn't be the problem, could it? The fact that the neck isn't capped?

[devilbunny]

I have given up trying to create a Normal Map for this mesh in ZBrush. I have used the UV Checker, Fixed Seams, and reapplied AUV and GUV tiles in all sorts of combinations. I deleted the lowest and highest SubDivs so the difference in poly counts wouldn't be so high, I have created my Normal Maps with different options, but I always get this seam. If it isn't a problem with the UVs, it must be a problem with the polys, right? But I can't find any.

Anyway, I imported the lowest and highest SubDiv models into max and used max's Render to Texture tool to create the Normal Map. Here's the model rendered in max, with just the Normal Map, and also the texture (Diffuse) and Specular map, and a touch of Displacement (12,000 polys):

http://anvil-studio.com/images/zbrush_dragon_051305a.jpg

http://anvil-studio.com/images/zbrush_dragon_051305b.jpg

If there are any seams there, I haven't found them yet. Sorry I couldn't share a solution to my original problem, but in the future I will certainly bring my models into max and manually assign UVs with careful seams before adding the high poly details in ZBrush.

[Drummer]

hey man.....
you have to find a solution, don't dispair !!
never give up!!
try to assign a GUV and to re-sculpt your model from the lowest resolution, for me it was a solution !!

try :cool: :tu:

[Poly pusher]

I wonder if it's to do with the way that ZB projects the normal map. I know that in Max if the projection cage that is used to create the normal map intersects with the actual geometry, you can at times get some odd looking results. However in Max you can play with the projection cage, and refine it.

I guess I was just wondering if there was some kind of undesireable intersection between the normal map cage and the gemoetry?:o

[devilbunny]

Drummer, that probably would work, but I'm not anxious to spend the time re-modeling the fine details. I'll just try not to get myself into this position next time.

Poly, you may be right. I had no problems making the Normal Map in max, the lores and hires meshes were very close in general deformation. I have seen the cage problem you describe when the lores mesh sits more inside the hires one.

I'm just going to keep working, I have a feeling the solution (or at least, a clearer understanding of the problem) will come to me eventually.