Bake seamless normal map

Normal maps are very useful when modelling for 3D Games and for low poly applications.  From today’s tutorial I am going to teach you how to bake a seamless, repeatable normal map. You can use this method to generate normal map using from any patterned/textured surface. Only limitation is, the surface you are using should flat enough to project on to a plane.

To start the tutorial you need to open the 3D Max file where you already having a textured surface. Tutorial I will not teach you how to make a good quality patterned/textured surface using 3D Max. If you need to learn that part, you may go through my following tutorial.

Modeling a Patterned Metal surface

This is the texture I am going to use.

To make the normal map, first select proper area from the texture which is tileable. I have selected following part, which is square in shape. Try to select a square shape, it will be easy to work with.

Draw a square plane with the same dimensions as the selected object part. Use Align to place the plane on top of the object. Then move the plane object little up until it does not touch the pattern object.

Press F10 to open Render Setup window, go to “Common” tab > “Assign Renderer” rollout and set “Default Scanline Renderer” as the “Production” method.

Select the plane object and from the main menu, choose Rendering > Render To Texture. (Shortcut for the Render To Texture dialog is 0).  Go to > “General Settings” rollout of the “Render To Texture” dialog and define the output path where you want to save the normal map texture.

Go to “Projection Mapping” group under “Objects To Bake” rollout, turn on “Enabled” and turn off “Sub-Object Levels”.

Click Pick button under the same group to display the “Add Targets” dialog and choose the object you want to bake onto the plane object (that means – textured surface). Then choose “Use Existing Channel” under “Mapping Coordinates” group, if it is not already chosen.

Scroll down an go to “Output” rollout and click “Add” to open “Add Texture Elements” dialog. Select and add “NormalsMap” from “Add Texture Elements” list.

Go to “selected Element Common Settings” group, and select “Bump” as “Target Map slot”. Then select the size of the map you need to have. For that I am going to select 256×256. Even smaller map will  be enough since we are going to make a texture which may not need that much details. However, if you need you may select larger sizes as well.

Now you have sett all the settings and ready to bake. Press the “Render” button at the bottom of the “Render To Texture”.

As the result, it will open the render window and render the texture. But it might not be the texture you are looking for. Don’t worry, after rendering it will automatically save your baked texture at the place you have specified. Go and see, it will be there as a .tga file and you may need Photoshop to open it. Open it from Photoshop.
This is my normal map.

If you have used TurboSmooth while modelling the textured surface, it may having rounded corners and will appear in the normal map in a different colour (pink). You have to do very simple correction to the map using Photoshop to remove this coloured corners. Use brush tool and paint 4 corners using background colour.
Now you are having the Normal map. You can use it by repeating to both directions without a boundary.
 
If you don’t know how to use the prepared map, follow the instructions.
•    Open Material Editor, select empty material slot.
•    Scroll down to Maps rollout, press button in front of “Bump” and set “Normal Bump” as bump type.
•    Set the prepared map as the Normal map of “Normal Bump”.
•    Draw a box, and lights around it and apply prepared material to box.
•    Render and see.

Modeling a Patterned Metal surface