Baking normal maps in Blender

[Werne]

I figured out how to bake a normal map in blender, but it turns out the mesh needs to be high-poly. So I subdivided the vertices to about quarter million, if I go any higher my comp stops responding, and baked the normal, but I can see the seams in the normal map, and they can be seen in-game too. So, how high should the poly count be?

 

By the way, why is the normal in some weird color, do I need to apply a NormalMap filter to it in Photoshop (though I probably will)? Here's a pic of the mesh I'm baking the normals for:

[calabi]

Theres no set high poly limit. As many polys as you want and can handle, to make it look good. The seams are probably nothing to do with the high poly its probably the baking process. Use xnormal to bake, its free the same as Blender but probably more straightforward.

 

That looks like an old version of Blender havent they updated the UI?

[Werne]

Yup, it's an old 2.49, I tried the new 2.5x but I find this one better. And I don't know why are the seams there, but I find xNormal too complicated to use and I tried to install it but it seems it doesn't support XP anymore, only 7 and Vista.

[dazzerfong]

It's in a funny colour because it's set in World Space mode. You're not supposed to subdivide it like that, you're supposed to use a combination of subdivision and Catmull-Clark subdivision to round off the edges.

 

Also, your UV Map for the hilt has some problems on it: try unwrapping is as a cylinder, and try to maximise the amount of UV map on the area given. Given that the sword is mostly longitudinal, make the textures a rectangle to avoid wasting resources.

Edited December 15, 2011 by dazzerfong

[LHammonds]

FYI - The whole point of making a high-poly model to a low-poly's UV is to capture the detail in the high-poly model and apply it to the bump map of the low-poly model.

 

If all you did was subdivide the model just so it has a higher poly count, you really are not doing anything different. Adding complexity just for the sake of adding complexity solves nothing. There has to be actual detail / differences for the process to work right. That means modifying the high-poly version...typically by going into sculpt mode and making small changes to the shape. Those changes can then be baked onto the low-poly version even though those changes are not actually on the low-poly model.

 

Apologies if you didn't just crank up the poly count but that's what it sounds like you did.

 

LHammonds

[dazzerfong]

He just simply subdivided, from his pictures. If he wanted to achieve a smooth edge effect, he would have used bevelling or Catmull-Clark modifiers instead.

 

Also, for objects as simple as swords, you really don't need to bake to make a normal map: using a heightmap is already more than enough in most cases.

[Werne]

@dazzerfong I didn't just crank up the poly count, I made some changes to the mesh, not much however, it's hard to work on 1 fps. And this was just a test, I wanted to see can I do it, but it didn't work out well. Though I managed to get rid of the funky colors I still don't know what I did.

 

@LHammonds I know that, but I'm unable to edit a high-poly mesh in blender, anything over 3000 vertices produces lag. The only way for me to edit a high-poly mesh is to open it in Maya and edit it there, which I did, but then blender crashed when I tried to import it.

Edited December 16, 2011 by Werne

[Ghogiel]

Also, for objects as simple as swords, you really don't need to bake to make a normal map: using a heightmap is already more than enough in most cases.

lies!

[darthsloth74]

Also, for objects as simple as swords, you really don't need to bake to make a normal map: using a heightmap is already more than enough in most cases.

lies!

 

Yes thats very true. A simple heightmap will not suffice, true you could do it for rivets and stuff but its not going to look very nice. A low poly sword will still look low poly. You need to make a high poly model, chamfer a lot of edges, cut in a lot of extra detail, model rivets and lots of other stuff and then bake to an optimized low poly model. Heightmaps will not do the job.

[dazzerfong]

@ Darksloth74:

 

You do know that if the edge is highlighted as sharp, it's going to stay sharp in the game? Rivets and stuff like that are EASILY made from heightmaps, just saying.

 

@ Ghogiel:

 

Lies? OK............

 

Main problem is, except for decals, my swords already have all the detail on them: that's why I don't need extensive normal maps.