Seam stitching is a feature that smooths unwanted hard edges in GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary rendered with baked lightmapsA pre-rendered texture that contains the effects of light sources on static objects in the scene. Lightmaps are overlaid on top of scene geometry to create the effect of lighting. More info
See in Glossary generated by the Progressive LightmapperA tool in Unity that bakes lightmaps according to the arrangement of lights and geometry in your scene. More info
See in Glossary.
When Unity bakes lightmaps, it identifies meshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary faces that are close together but separate from each other as being separate in lightmap space; the edges of these meshes are called “seams”. Ideally, seams are invisible; however, they can sometimes appear to have hard edges. This is because the GPU cannot blend texel values between charts that are separated in the lightmap.
Seam stitching fixes this issue. When you enable seam stitching, Unity does extra computations to amend the lightmap to improve each seam’s appearance. Stitching is not perfect, but it often improves the final result substantially. Seam stitching takes extra time during baking due to extra calculations Unity makes, so Unity disables it by default.
When you enable seam stitching, the lightmapper identifies the pair of edges that it should stitch together, and produces illumination which is as smooth as possible across the seam. This applies only to straight edges which run horizontally or vertically along chart boundaries in the atlas, and is designed to work with rectangles which are axis-aligned in UV space.
Seam stitching works with the Progressive Lightmapper. Seam stitching only works on single GameObjects; multiple GameObjects cannot be smoothly stitched together.
You can enable seam stitching on any GameObject with a Mesh RendererA mesh component that takes the geometry from the Mesh Filter and renders it at the position defined by the object’s Transform component. More info
See in Glossary component. In the Mesh Renderer Inspector, navigate to the Lightmapping section and Stitch Seams.
Alternatively, you can use the MeshRenderer.stitchLightmapSeams API.
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.