Line renderer width issues (Unity)

unity

#1

Hello everyone,

I’ve been trying to make a motion trail in Unity, but my character is static while the background is moving, so I’m opting for a line renderer with fake velocity.
Everything has been working well so far, but I’m having a problem with the texture of the line with varying width, my texture gets jagged between points. I’m not talking about “turning a corner” between points, as my line is perfectly straight. Is there a fix to this? Or is there a workaround that you would recommend?

Thanks!


#2

You cant tell Unity line geo to generate spans on both U and V…this is an artifact of triangle density

In Unity it will better serve you to have a custom procedural geo tool.

In this particular effect taper the textures and keep the geo straight.

You can also emit non-rendered partices with velocity and use the ribbon module to draw a line between them, it may be able to create more cross sections to hide the jaggy


#3

Torbach, thank you so much! I ended up replacing the texture and maintaining the width consistent in the geo like you proposed.

I also tried using the ribbon inside the particle system component, but I got a lot of awkard intersection issues when moving the trail. I tried playing with the particle emission, but I couldn’t get rid of it completely.

Regardless, now it’s looking exactly how I wanted, thanks again!

ribbon


#4

any bias causes rotations of the ribbon or trail and those cause kinks of the texture

afaik it is a difficult problem in rtvfx ; procedural geo creation seldom produces ‘perfectly’ smooth [bulbous] geo without killing performance.


#5

It’s possible to fix the artifacts in the first post with custom trail geometry and shaders.

https://forum.unity.com/threads/help-giving-a-productionaly-generated-symmetric-mesh-stretched-the-mesh-in-a-weird-way.545413/#post-3605017

The intersecting / overlapping geometry on turns is harder.