Download

Faces render black

Hi all,

A problem occurs with some faces. As you can see in attached file, they render black.

This object was created in 3ds max and export as fxb file. It has 2 uvw channels.

Do you have any clue of what might be wrong ?

thx a lot.

Regards,
Nico

Does this black thing appear after you rebuild the light, or is it also here when you use dynamic lightning? :slight_smile:

Hi fighter,
it appears when i rebuild the light.
the light is a simple static DirectionalLigth (+BP Sky Sphere)…I don’t know what’s wrong :confused:

Nico

Your UV layout for the lightmap is pretty bad. Consider stretching the islands so that you’ll fill up more of the space, slightly distorted UVs don’t really matter when it comes to lightmapping.
Also consider increasing lightmap size. You can visualize the current lightmap texel density in the viewport by changing the view mode.

Here you can read more about lightmaps and how to create them :slight_smile:

http://www.worldofleveldesign.com/categories/udk/udk-lightmaps-01-basics-and-important-principles-for-creating-using-lightmaps.php
http://www.worldofleveldesign.com/categories/udk/udk-lightmaps-02-uv-techniques-and-how-to-create-second-uv-channel-in-maya.php

fighter, jonimake,
thx for your answers/advises.

i re-unwrapped my object, following various techniques from many tuto ^^ (mainly this one : https://www.youtube.com/watch?v=VyTH0Xtn_D4)

uvs seem clean and fine to me (every islands have at least 3px padding from each others). no more black face (yes !), but as you can see below, shadow bleeding problem occurs :confused:

i tried different uvs layouts/templates (i don’t know how you call it), it doesn’t solve.

but magic happens when i turn light from static to movable…everything becomes as it should be, clean and smooth.

i’m ok with that for now, but from what i know, movable lights “cost” a way more than static, so it might become a problem when my level will grow up. so, again, if you have any suggestion…

regards,
Nico

Lightmap resolution and also placement. As the lightmap is small resolution it can fall halfway between pixels giving the effect you see there. Up the resolution slight and see if it still persists. Or you can just slide the UV island across slightly.