Loading...
> >

Iray, Displacement and Seams oh my...

Groovy PatrolGroovy Patrol Posts: 117
in The Commons

I've been using Daz for around a month now.  I've spent the last 2 weeks trying to create a workflow that would result in a seam-free displacement map for Genesis 2.  Thanks to the information found in this forum I've come very close, but still not perfect.  Here's a shot of the issue.  The seam is worse across texture tiles, but is also evident on seams occuring on the same tile, as shown by the seam running up the neck from the shoulder.

The morph was created in Zbrush and exported via goz.  The displacement maps were baked in Zbrush as well.  The min/max settings for displacement were taken from the values assigned by zbrush to the face and torso objects exported solo to Daz via goz.  I have tweaked settings until my eyes bled to no avail.  I noticed normal maps baked in Zbrush also have seams in the same places, while normal maps baked in Mudbox are seamless.  Unfortunately displacement maps baked in Mudbox have the same seams seen in Zbrush.  I could probably get away with just a normal map, but the displacement adds quite a bit to the surface.  Here's a comparison shot with a quick test texture:

Any help would be greatly appreciated.  I hope I'm missing something simple.  I did stumble across an interesting article that talks about this issue, but its solution would require re-uv'ing the figure.  http://polygonspixelsandpaint.tumblr.com/post/19733351349

Comments

  • Cris PalominoCris Palomino Posts: 12,482

    Try working with displacement strategically.  The normals appear to be working, now use the displacement to enhance areas, not overall, and keep a good margin from seams and see if that helps.

  • Groovy PatrolGroovy Patrol Posts: 117

    Thanks for the suggestion.  That's basically what I have been considering.  I have to say the prospect of avoiding every seam on the tiles and between them is less than ideal.  I suppose sometimes artistic vision must be tempered by the physical limits of the medium, digital or otherwise.  I did just think of something else to try to help confirm it's not a baking error and is actually an inherent issue with the way the seams meet in uv space.  The clean normal maps I was able to bake make me lean toward the opinion that it is possible to get a clean displacement to cross a seam, since the pixel shearing issue I learned about in the above linked article would apparently affect both normal and displacment maps.  I'll report back with the results of my experiment.

  • Groovy PatrolGroovy Patrol Posts: 117

    Well I tried hand painting a displacement map in mudbox.  Flood filled a layer with middle grey and painted some lines in black and white crossing the seams.  It was evident it the hand painted map was going to have the same issue when I sent it over to preview in the bump channel.  Even if the uv's were aligned, the texel density difference between the tiles, especially the face and torso, is great enough that any height map crossing it will show artifacts.   I'm going to have to try a test re-uv and see if it does indeed solve the issue.

  • Oso3DOso3D Posts: 15,085

    I think there's a good argument for making torso (and possibly limb?) texture density twice that of face.

     

     

  • AnotherUserNameAnotherUserName Posts: 2,727

    He looks very cool! I hope that you are going to put him up for sale on DAZ when he is finished.

  • Groovy PatrolGroovy Patrol Posts: 117
    timmins.william said:

    I think there's a good argument for making torso (and possibly limb?) texture density twice that of face.

     

     

    For my purposes a consistent resolution across all skin tiles would be best,  although it would waste a large amount of texture memory for areas that would most likely hardly ever be seen.  I did create an extra UV tile and split off the top part of the torso to up-res it to match the face more closely.  Even with the density closer, the seam still appears, as the pixels are running in different directions and don't match exactly where they meet.  This is especially bad with displacement, as the artifacts catch shadows and makes them easily seen.  I'm experimenting with ptex, which does give the model a consistent resolution, but is still not a perfect solution.  For now I'm going to see if I can work around the seam issue, as judging by the products in the store, many people have been successful using the gen 2 standard uv's.

     

    AnotherUserName said:

    He looks very cool! I hope that you are going to put him up for sale on DAZ when he is finished.

    Thanks!  That is the plan, assuming of course Daz is interested.

Sign In or Register to comment.