1
$\begingroup$

I have a mesh (a rock wall) that I would like to split into pieces and export each piece for a game engine. The mesh has a smooth, undulating surface and when all the sections are merged into a single mesh, it looks the way I want it to. However, when I split the mesh into pieces, Blender recalculates the normals along the edges causing a very visible change in shading.

I would like Bender to leave the normals alone, or maybe give me some way to edit the normals manually. Can I do this?

$\endgroup$
  • 2
    $\begingroup$ You need to use custom normals. It's the only way to preserve the smooth shading on the edges you split. $\endgroup$ – Jaroslav Jerryno Novotny Dec 10 '15 at 11:50
  • $\begingroup$ How do you use custom normals? I tired adding a normal edit modifier to my mesh. Not only does it automatically recalculate my normals to cause a 'radial' effect, but if I split my mesh it still recalculates again along the new seam. $\endgroup$ – kitfox Dec 11 '15 at 9:44
1
$\begingroup$

I created a Blender add-on for this exact purpose called TiNA which allows you to easily transfer normals between objects. TiNA basically turns the somewhat overwhelming Data Transfer Modifier into a set of more comprehensible operations.
There's a special branch for those using Blender 2.80 beta.

TiNA|

 Hotkey           | Operation 
------------------|-------------------------------------------------------------------
 Alt+N            | Transfer Normals from selection to active object
 Shift+Alt+N      | Transfer Normals from active object to all other selected objects
 Ctrl+Shift+Alt+N | Clear Custom Normals data for entire selection
 Alt+W            | Wrap Normals

In your case you could transfer the normals from an unsplit duplicate by selecting all objects, and - with the unsplit duplicate as your active object - hitting Shift+Alt+N.

Example results

$\endgroup$
  • 2
    $\begingroup$ maybe you need to detail the feature, usage, effect, or other information...?? $\endgroup$ – FanFanD Yun Feb 27 '19 at 6:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.