I’ve a model which has both UV0 & UV1 channel exported from Maya. When I use that model with Model Component and use lightmapped, it is working properly. But when I use with Render Component and tick lightmapped, then it says UV1 is missing.
Project link (Model Component): https://playcanvas.com/project/835847/overview/test
Project link (Render Component): https://playcanvas.com/project/835850/overview/test2
Is it problem with the Render component or with my model?
yaustar
September 30, 2021, 9:38am
2
@mvaligursky Any ideas here?
We have some issues here, and a temporary workaround is to scale Lightmap Size Multiplier as shown in the image:
opened 02:33PM - 29 Jul 21 UTC
bug
area: asset import
blitz candidate
It is known that the editor is currently unable to unwrap UV1 for GLB models; ho… wever, even if an uploaded model has a UV1 channel, the editor will always report that it is missing when slecting a RenderComponent to be lightmapped. ModelComponents do not exhibit this behavior. When launching the scene, the RenderComponent will not respond to lightmapped lights, while the ModelComponents will.
Provide as much information as possible. Include (where applicable):
* URL to a simple, reproducible test case that illustrates the problem clearly:
https://playcanvas.com/editor/scene/1202294
### Steps to Reproduce
1. Open Project
2. Verify that lightmapping is enabled on RenderComponent, ModelComponent, and Lights (While separate files, imported FBX are identical)
3. Launch Project
opened 10:38AM - 30 Sep 21 UTC
enhancement
area: graphics
The json model format provides lightmap area data generated by unwrapping, which… allows us to estimate lightmap size. As render components come from glb, we don't have the information and default area of 1 (pixel) is used.
To get this to work correctly, a lightmap size multiplier needs to be set high.
The proper solution is to improve Lightmapper.calculateLightmapSize function to provide sensible defaults for render component (see the TODO note there).
Related:
- https://github.com/playcanvas/editor/issues/478
- https://forum.playcanvas.com/t/uv1-not-working-with-render-component/22191
1 Like
HI @mvaligursky , Thanks for the reply.
Any idea why the texture is like that on the pillow on the sofa and on the entire model after lightmapping.
Hi @yaswanth ,
It looks like it’s because the lightmap is so small (only 32x32) Raising the multiplier should give you better results.
3 Likes
Hi @eproasim , Thanks for the reply, It is working fine now.
There will be a fix for this in the next engine release, likely next week
playcanvas:master
← playcanvas:mvaligursky-lightmap-sizing
opened 04:58PM - 05 Oct 21 UTC
Fixes https://github.com/playcanvas/engine/issues/3528
The size of the lightm… ap area is based on the world space bounding box of the mesh instances, and not just multiplied scales of the nodes - as that didn't handle the case where vertices are scaled down and compensated by scale on the node.
Now all json model, glb model and render component estimate similar size.

2 Likes
Thanks for your support. We’ll update our project.
yep, the fix was released few days ago, so all should work now.