Normal map Problems

5 replies [Last post]
maxkid's picture
Posts: 20

Hi  guys,

I  started  with  this  model  to  eventually  to  make  it  low poly so  i  started with  8  sided  cylinder ,it  works  well  with  turbo  smooth  but  normal  map  looks  really  bad ,any  tips  to  work  around  with  my  existing  model  or  do  i  need  to  create  good  40  sided  cylinder  to  come up  with  a  decent  normal  map  ,i  tried  whole  night  just  with  mapping cylinders  with normal  map    but  only  40  sided  cylinder  looks  alright  and  rest  of  them  just  look  bad.............pls  any  tips ,advice  welcome ...i  am  trying  to  create  portfolio ,but  just  get  stuck  with  this  normal  map  thing...

1)  does  cylinder  need  to  be  really  rounded  for  normal  map  to  work  properly ,like  is  8  or  12  sided  cylinder  bad  start  if i  making  this  for  game  asset
2) any  tips  tutorials  on  normal  maps i  have  gone  through  couple  of  them  but  most  are  either  characters  or  flat  planes  not  cylinders  exactly
3) any  other  methods  for  coming  up  with  normal  maps ,i  have  tried  same smoothing  groups ,as  wells  same  smooth  for  whole  object  but  still  any  other tips ,technique  etc

 

maxkid's picture
Posts: 20

pls anybodyInnocent

JackyBoy's picture
Posts: 344

I don't really understand the images you have posted, what do they relate to?

Also you don't state whether the "40 sided cylinder" is the High poly or the Low poly? Also what are you baking it in?

Have a read through this. It has so much information in there to read about.

Maya|Zbrush|Photoshop|UDK

metalliandy's picture
Posts: 3188

Hey Maxkid,

The silhouette of the LP will always dictate the shape of the object no matter what the normal map is doing so they only way to get a better shape is to add more geometry. As a rule normal maps can only represent details that are fine or recess into the surface...anything else should be added with geometry.

 

When deciding the number of sides you have to take into account how big the object is in relation to the player and how closely it will be viewed.

Generally i think that an oil barrel, a tyre or something around that size should have around 22 sides or so but a small wire or a piece of rebar that is less than an inch wide should have around 4 or 5 (depending on your poly budget) but in a portfolio you can get away with a little more as the point of it is to look good (just dont go crazy with 40 sides on a tyre Sticking out tongue)

 

How big is the object you are creating?

It would help if you post the normal map and LP mesh with wires so we can take a look at it and give better crit.

 

As for tips...

  • When adding smoothing groups split your UVs in the same place and move them apart by a few pixels in UV space...this will stop the black shadowing that can happen around the edges when baking as it stops the vert normals being represented incorrectly and will also stop smoothing group seams.
  • Explode your HP and LP meshes so each part is separate when you bake which will stop tracing artefacts.
  • Remember that adjusting your cage can dictate how the rays are cast which will affect your final bake. (great for stopping the wavy lines on cylinder edges)  
  • If you cant or don't want to wait for 4xAA when baking maps turn it off and bake at double resolution and resize and unsharp mask @around 40 for the same effect. (If you want the final map to be 2k bake at 4k with AA off and then resize to 2k and sharpen).

 

Hope that helps Smiling

maxkid's picture
Posts: 20

hey  there,

Thanks  for  answering my  query ,i  thought  so  normal  map  is  not  going  to  make  my  8  sided  look  round ,i  will  try  it  with  24  or  so ,remodel ,uv &  tex  and  post  it  again ,Thank  u   very  much ,Thank  you  for  all  the  tips & Thank  you  for  the  link  jackboy

cheers,

maxkid

Anonymous's picture

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