My understanding was that scaling acceleration by delta t squared during the verlet integration step would make the simulation frame rate independent. Unfortunately I'm having some issues — when I change the frame rate it does affect the simulation. Am I missing something? Is verlet integration the only part of the current node setup that compensates for the frame rate? So far been able to follow everything else just fine, I'm going to keep going — any help would be appreciated:)
Hi sjman,
I'd go over it again, using Delta Time should make it Frame rate independent. If it doesn't, you have made a mistake somewhere. I do not and cannot know where exactly your mistake occurred; you'll need to check each Node and its connections. I would not recommend to leave it as is and 'just keep going'!
Hi Martin,
Thanks for responding:) That's what I thought as well. So I downloaded the project files and opened up the Verlet Collisions file to check the nodes one by one. However, even in the demo file available for download, when I change the frame rate the simulation changes pretty dramatically. As the frame rate increaseses the particle picks up a ton of velocity.
Is anyone else noticing the same thing? Maybe I'm just misunderstanding the concept of frame rate independence:)
I really recommend that you go through the lesson again, from scratch. Do not use the Project File, but add the Nodes one by one, as per the video.
This is extremely hard to troubleshoot otherwise. (It looks like only one of the axes (gravity?) uses Delta Time...)
Other people have done this course without running into this issue, so I'm pretty sure you have made a mistake somewhere along the line (maybe even in an earlier lesson).
I have watched the whole course (some time ago) and didn't find any mistakes, but I haven't actually done this in Blender, so I might have missed something.
When I find the time, I will try this myself and see if I run into any issues.
Hi thanks for taking a look at this:) I will follow your advice, although I did want to clarify one thing. I have not been using the course files as I follow along, I only pulled it up as a reference to double check my work when I ran into this issue. The video I uploaded is directly from the course file, if you download it and open the verlet collisions file, you should be able to reproduce the error. Thanks:)
Gotcha, I'll do that, will be back in a few days haha.
Although if you are able to grab a few minutes and get a chance to open the Verlet Collisions course file to verify you're seeing the same issue, let me know. No need to diagnose anything just let me know if you experience the fps issue. Just want to know I'm not crazy.
Totally understand if you can't, I'm sure you're busy:) Thanks
Can confirm that Verlet in the course files changes simulation speed with different frame rate