I’ve been diving into Unity’s VFX Graph for a project, and I’m definitely hitting a wall here. I’m trying to create a particle system where each particle has its own unique strip trail. The idea is that when a particle collides, it triggers a GPU event that spawns a new particle, which should then create a trail. However, I’m facing a frustrating issue: when new particles spawn continuously, the trails start stretching or seem to teleport. It looks like Unity is reusing an index or a slot in the buffer that should belong to the previous particle’s trail.
I attempted a workaround by manually killing the trail before the source particle dies. I set up a logic comparison between Age and Lifetime to manage this, but it didn’t yield the results I hoped for. It seems like no matter what I try, the trails glitch out and do not behave as intended.
I’ve looked into different approaches using VFX Graph features, but I’m starting to feel a little lost, and I am open to using script solutions if needed. I know there’s gotta be a way to ensure that each particle has a completely clean trail and that we’re not inadvertently tying trails together. Has anyone encountered this issue and found a solid way to manage unique strip indices for each particle?
I’m thinking I might need to implement some sort of unique identifier system for each particle’s trail, but I’m not really sure how to approach that in VFX Graph or if a script could help with this.
If anyone has suggestions or insights into how I can troubleshoot this, I would really appreciate it! It would be awesome to share any tips, tricks, or even examples of similar implementations you’ve done. Here’s a link to a video showing the issue in action (sorry for the slightly poor quality): [Trail Glitch Video](https://streamable.com/9s5u9o). Also, here’s a snapshot of my current graph layout; perhaps it can help point out what I’m missing. [VFX Graph Showcase](https://i.sstatic.net/gYWGvEFI.jpg). Thanks in advance for any help!
It sounds like you’re really diving deep into the VFX Graph! The trail issue you’re experiencing with your particles can indeed be tricky, especially when it comes to managing unique trails for each particle.
First off, you’re right about needing to ensure that each particle has a unique trail. One common approach is to use a unique identifier for each particle. You can do this by setting up a custom attribute in your VFX Graph, like an integer or a float that increments for each new particle generated. This way, you can easily track which trail belongs to which particle.
In terms of implementation, consider creating a separate “Trail” system that is responsible for managing the trails of the particles. When a particle is spawned, generate this unique ID and use it to set properties in your trail VFX context. This can help prevent Unity from reusing slots inadvertently, which seems to be causing the teleporting/stretching effect.
Also, your idea about killing the trail before the source particle dies is a good start! Pair that with your unique identifier by possibly marking the trail for destruction right before the particle dies. Just make sure that the trail is completely reset for the next particle to take over that ID. This might eliminate the glitches you’re seeing.
As for the logic comparison between Age and Lifetime, make sure you’re checking it correctly in your particle’s life cycle. It might help to create a dedicated timing or event system to manage when trails should be destroyed or renewed.
If you’re still hitting walls, scripting could also help. Creating a small script that tracks the active particles and their corresponding trails could give you more control. You could manage trail state updates more effectively outside of the VFX Graph.
Check out the links you shared, especially the video. Sometimes visual examples can lead to breakthroughs. It could also be worth exploring the Unity forums or the VFX Graph Discord for real-time help from others who have faced similar issues.
Good luck, and don’t hesitate to experiment with different setups! Unity VFX Graph provides a lot of flexibility, so keep trying!
The trail stretching and teleporting issue you’re encountering typically arises because Unity’s VFX Graph strip outputs rely on particle indices internally, which can indeed lead to trail recycling or overlapping issues when particles spawn continuously. A robust workaround is to assign a unique identifier attribute to each particle at spawn time, either directly through GPU events or via scripting (using a custom incrementing integer value stored in the particle’s attributes). Then, instead of relying on the default strip indexing, set the strip index explicitly according to this unique identifier, thus ensuring that each trail remains cleanly separated and accurately tracks its associated particle.
If directly assigning unique IDs in the VFX Graph becomes complex, another solution is to utilize scripting in Unity to feed a unique identifier into VFX Graph through exposed properties or event attributes, incremented per particle spawn event. Then, within the VFX Graph, bind this custom identifier attribute to the trail strip index. Combining scripting solutions with VFX Graph’s GPU events effectively prevents these visual glitches and ensures each particle maintains a distinct trail. Examining your current graph layout and video, implementing a unique strip ID through this method should solve your issue completely and avoid unintended index reuse.