Lightmap Density issue?

Hi guys,

Safe to say I am relatively new to UE4. Having recently come across this plugin I was keen to test it with my current work flow as it has the potential of skipping out the 3ds max faf which occurs every time I export something from rhino into UE4.

The question / observation: When viewing the imported geometry in "Lightmap density" view (which shows which objects are receiving the right amount of resolution); the imported geometry does not have a uniform UV distribution. On the left is the fabric engine imported geometry and the right the same geometry that has gone through 3dsmax.

Is there a known work around or is this work in progress?

Many thanks for taking the time to read this,



  • a_r_poncea_r_ponce Posts: 1

    Not sure if this could help, but you might find a streamlined workaround using this tutorial

  • willbr21willbr21 Posts: 2

    Thanks ponce for the response. In hindsight what I should have included in the screen shot was the example of the geometry after a "box mapping" (see below). The pattern is stretched in weird ways and I assume we should be looking for a uniform grid across all geometry (seen on the right in the screenshot above) irrelevant of its shape.

    Just as a note the pattern you see in "lightmap density view" is confusingly the same as the texture used in the tutorial you provided. More importantly however is the way in which he maps the texture which affects how the lightmap density is mapped in UE4 (not the texture map). Alas anything I do I still cant achieve that uniform lightmap density that can be achieved through 3dsMax.

  • HelgeHelge Moderator, Fabric Employee Posts: 314 Fabric Employee

    Hey @willbr21,

    thanks for your feedback. Currently out lightmap UVs are based on a binpacking algorithm - so they can result in stretching. I've logged FE-8545 on our end to look into this.


    Research Engineer @ Fabric Software

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