gregjenings

Hi everyone,

I’m trying to create a moving light strip / chasing or scanning effect in Houdini.

The effect I’m trying to achieve is similar to an LED strip where:

The entire strip remains constantly bright/emissive.
A moving section of light travels along the strip/path.
The moving section has a different color and/or higher emission intensity than the rest of the strip.
The moving section should produce a Glow/Bloom effect.
The bright section continuously moves/chases along the path.

I have been trying to achieve this using an emissive material on a path/strip, along with Glow, and I have set up a different color/emission for the moving section.

However, my current setup is not working as expected, and I’m not seeing the emissive effect in the final render.

I have attached/enclosed my Houdini setup file

I’m specifically sharing the file because I would really appreciate it if someone could look through my existing setup and point out what I have done incorrectly.

What is wrong or missing in my current node setup?

Why is the emissive material not appearing in the render?

Is my moving light mask/attribute being generated correctly?

Is the emission being transferred/applied correctly to the geometry?

Is there an issue with the material, render settings, or Glow/Bloom setup?

If there are mistakes in my current approach, I would really appreciate an explanation of what the mistake is and how I can fix it.

if there is another/better approach that can achieve the same visual result, I would also be very happy to learn about it.

Any help in reviewing the attached file and explaining where I’m going wrong would be greatly appreciated.

ronald_a
because you load your points into the stage, they shadow your pointlight. either dont load them or prune them

Thank you, Ronald. You were correct to point out the issue, and it worked!

I am now facing another issue regarding animating the light intensity in a particular sequence. So far, this is what I have managed to achieve, and I’m sharing the .hip file here for reference.

Unfortunately, the intensity is not animating as expected, and I’m also unable to view the render output.

Any suggestions or an alternative method to achieve this would be highly appreciated.

Thank you in advance for your help!

Hi everyone,

I’m trying to understand an issue I’m having with lights in Houdini.

I have created points arranged around a circle and am instancing/copying lights onto those points. The lights appear correctly in the viewport, but when I render the scene, the instanced/copied lights don’t seem to contribute any illumination to the render.

I’m trying to figure out whether this is:

* A limitation of instancing/copying lights onto points
* A rendering/lighting setup issue on my side
* A known bug
* Or something specific to the renderer I’m using

Has anyone encountered this behavior before? If so, could you explain what is actually happening and what I might be missing?

I’d also appreciate a workaround or the recommended way of creating multiple lights distributed around a circle while still having them contribute properly to the render.

One other question: would the same approach work if, instead of lights, I used emissive objects/materials (for example, small emissive geometry copied/instanced around the circle)? If so, are there any important differences in how the renderer treats emissive geometry versus actual light objects?

If possible, I’d really appreciate an explanation of the underlying reason rather than just a workaround, as I’d like to understand how Houdini handles instanced lights during rendering.

Thanks!