Home Technical Talk

Vertex normals issue?

juanoblagu
polycounter lvl 6
Offline / Send Message
juanoblagu polycounter lvl 6
Hello everyone, im still trying to figure out these issues that always haunt me in my models, getting this weird artifacts in my low poly meshes (the final character has a normal map that i get out of marmoset toolbag later) this a fish gill where i get weir change of color, i tried triangulating but it wont really help, tried unlocking normals and averaging but none work, someone told me once to harden edges but it would show in the final mesh since the high poly mesh has the gills kinda rounded (info that would show in the normal map mentioned before) appreaciate any help.





Replies

  • Neox
    Offline / Send Message
    Neox godlike master sticky
    it is an averaged normal, what are you expecting it to do? there are many edges pulling on that normal. if you want it to face foward, you could introduce a hard edge to the corner of the front gill. or you could manipulate that normal by hand. you could add more geo to compensate, or use normalmaps
  • juanoblagu
    Offline / Send Message
    juanoblagu polycounter lvl 6
    Neox said:
    it is an averaged normal, what are you expecting it to do? there are many edges pulling on that normal. if you want it to face foward, you could introduce a hard edge to the corner of the front gill. or you could manipulate that normal by hand. you could add more geo to compensate, or use normalmaps
    i use normal maps but wouldnt that artifact show after i put on the normal map still? also, whenever i delete the dioagonal edges (triangulation) the proble is still there
  • Fabi_G
    Offline / Send Message
    Fabi_G high dynamic range
    Does the lowpoly shading look good with the normal map applied? Hard edges are certainly useful to control the shading of the lowpoly, especially at steep angles - just remember to split the UVs along hard edges to avoid artifacts! Maybe check out  Making sense of hard edges, uvs, normal maps and vertex counts?
  • Neox
    Offline / Send Message
    Neox godlike master sticky
    Neox said:
    it is an averaged normal, what are you expecting it to do? there are many edges pulling on that normal. if you want it to face foward, you could introduce a hard edge to the corner of the front gill. or you could manipulate that normal by hand. you could add more geo to compensate, or use normalmaps
    i use normal maps but wouldnt that artifact show after i put on the normal map still? also, whenever i delete the dioagonal edges (triangulation) the proble is still there

    comes down to the angles on the surface, the normalmap might just carry it.
    Tho even with a working normalmap, we could get issues once the map is compressed, or mipped

    the problem arent the diagonals, those are there whether you make em visible or not. the issue is the undercut behind the gill
    what you could also do, is eliminate the undercut, not sure if it is really needed, i guess it will cause issues when baking for being so tight.
    Also possibly lower the angle, anything around and above 90° can cause issues, because its a lot of gradient in the lowpoly, therefore normalmap. especially when compressed this will likely bug out


    another note, if you add geo you also want to use it, you have a ton of loops that dont do much with the silhouette right now

Sign In or Register to comment.