[Jesse Stormer]

For anyone else who finds this — make sure your solid layer for ‘persistent property’ is LARGER than your comp. Those particles touch the edge and detect that there is no reference for rotation, they begin to rotate, but then snap back as they return to the center. Same with particles being emmitted from off-comp, they will enter comp with rotation.

[Jesse Stormer]

This is pretty genius, I’m also trying to do something similar — but I want to get a grid array look on the surface of an object. For instance, a human, or animal. I can’t figure out how to get things to clone onto the surface in a grid pattern, I’ve gotten thinking particles to spawn/birth in a grid pattern (using a very tight tile alpha), but I also can’t limit how many spawn in 1 location so I wind up with multiple particles on each grid point location. Any theories on how to get a simple matrix or cloner setup to clone in a grid array on the surface of a more complex shape?

[Jesse Stormer]

I hope I’m entertaining someone… just going on and on to myself.

Here’s the expression to find the world position half way between two nulls/positions:

x = [(thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[0]+thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[0])/2]-960;
y = [(thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[1]+thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[1])/2]-540;
[x, y]

Here’s the expression to scale the image between them – also using world coordinates.

x = (thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[0]-thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[0])/19.2;
y = (thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[1]-thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[1])/10.8;

if (x>y){
[x, x];
}else{ [y, y] ; }

[Jesse Stormer]

Well crap. That doesn’t work with parenting, I had to modify it to work with world position.
Now I broke my ‘find position half way between two nulls’ expression.

how do i convert this to use world position? (it finds the location half way between two nulls/positions)

x = (thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[0]-thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[0])/2;
y = (thisComp.layer(“Lower Left Null”).toWorld(anchorPoint)[1]-thisComp.layer(“Upper Right Null”).toWorld(anchorPoint)[1])/2;
[x, y]

[Jesse Stormer]

WOW I am really pleased with myself. I figured it out. Hopefully this helps someone else.

x = (thisComp.layer("Upper Right Null").transform.position[0]-thisComp.layer("Lower Left Null").transform.position[0])/19.2;
y = (thisComp.layer("Lower Left Null").transform.position[1]-thisComp.layer("Upper Right Null").transform.position[1])/10.8;

if (x<y){
[x, x];
}else{ [y, y] ; }


[Jesse Stormer]

I’ve made it a little farther… now I just need to figure out the ‘if\then’ parts…

x = (thisComp.layer("Upper Right Null").transform.position[0]-thisComp.layer("Lower Left Null").transform.position[0])/1920;
y = (thisComp.layer("Lower Left Null").transform.position[1]-thisComp.layer("Upper Right Null").transform.position[1])/1080;

[x, y]

[Jesse Stormer]

Aha! Thanks so much!

Do you happen to know if I can have the volumetric come out in a different pass, and not applied to the c4d composited image? the volumetrics MURDER the alpha, and I’d really like to be able to choose how much they are applied without re-compositing every pass afterward.

[Jesse Stormer]

Thanks guys, this helped a lot. I found a few other threads where nobody has posted an answer yet, so I’m going to link them here. I’d also like to add a few keywords here to get some better hits on google results.

C4D, GI, Reflection, HDRI, bake, problems, splotchy, QMC,

[Jesse Stormer]

Wow, Adam. Thank you so much, I’m very impressed that you were able to figure this out! I’m still not 100% on why this didn’t work with a different type of spline. So, what was your process for converting the spline to MoSpline? It’s just as simple as telling the MoSpline to reference my original splines? Your solution is curiously/frustratingly easy… considering how long I spent on this dilemma.

[Jesse Stormer]

Then there’s the fact that when I bake everything that’s animated on the splines, and try to reduce keys — it looks like this: