# Problems with lighting and stuff

**URL:** <https://forums.sketchup.com/t/problems-with-lighting-and-stuff/351101>\
**Category:** V-Ray for SketchUp\
**Created:** [October 30, 2026, 7:41am UTC](https://forums.sketchup.com/t/problems-with-lighting-and-stuff/351101 "2026-10-30T07:41:01Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![margottenenbaum227](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@margottenenbaum227](https://forums.sketchup.com/u/margottenenbaum227)\
**Post date:** [October 30, 2026, 7:41am UTC](https://forums.sketchup.com/t/problems-with-lighting-and-stuff/351101/1 "2026-10-30T07:41:01Z")

</div>

I’ve been trying to render these hidden LED strips inside the ceiling cove, but they kept making these weird lines. Tried almost everything including changing the cove distance from the wall, changing the rectangle light directionality, using mesh light, and even changing the LED strip directions so it would beam towards the back ceiling instead of the upper part. None of it works at all. Can anyone give me some advice?

 ![Screenshot 2026-10-30 143759](https://global.discourse-cdn.com/sketchup/original/4X/a/1/9/a1925f39ed340b0d950690b2dbe257d8464740f9.jpeg)

---

<div class="post-metadata">

**Author:** ![mihai.s](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/mihai.s/32/202022_2.png) [@mihai.s](https://forums.sketchup.com/u/mihai.s)\
**Post date:** [October 30, 2026, 8:30am UTC](https://forums.sketchup.com/t/problems-with-lighting-and-stuff/351101/2 "2026-10-30T08:30:23Z")

</div>

Which version of V-Ray?  
How is the geometry created? Groups?  
What are your render settings?  
What are your light settings?  
Any other useful information?

Quick test

 ![vry-02](https://global.discourse-cdn.com/sketchup/original/4X/a/7/5/a75e641b3c142dfb95c56b2cb8976c361cf106c3.jpeg)  
 ![vry-03](https://global.discourse-cdn.com/sketchup/original/4X/e/2/1/e211ba475f7cffb36645b5b68f00ac7eec25d6a8.jpeg)

---

<div class="post-metadata">

**Author:** ![virse\_ai](https://avatars.discourse-cdn.com/v4/letter/v/85f322/32.png) [@virse\_ai](https://forums.sketchup.com/u/virse_ai)\
**Post date:** [October 31, 2026, 4:59pm UTC](https://forums.sketchup.com/t/problems-with-lighting-and-stuff/351101/3 "2026-10-31T16:59:36Z")

</div>

Those streaks usually show up when the light sits on or inside the cove surface, so the shadow ray starts inside the geometry. Pull the strip a few millimeters off the face, toward the open side of the cove, and point the emitting side into the room rather than into the ceiling.

If you are using a rectangle light, try a thin mesh light in its own group so it does not share faces with the cove. Also check that the cove faces are oriented outward, because reversed faces often draw those bands even when the light settings look right.