Playing with defocus

[bapestar]

Some great tips in here.

I’m still trying to get my head around gradient engrave. Understand the physics of why you want to do it with edge lit, and also have a pretty good command of Illustrator. But how are people preparing these gradients?

I’m assuming that for a complex shape, you want to do an even gradient running vertically through all of the parts (in otherwords, any horizontal “slice” across the image would have the same grayscale level). In Illustrator, the only way I can figure out how to do this is by making it a compound path and gradient filling that. No problem… until I want to send it to my GF

What’s the right workflow from having a gradient fill on a compound path?

1. Save as SVG with a gradient and compound shape (I don’t think that works)
2. Expand the gradient and export?
3. Expand the gradient, release the compound shape, pathfind and clean up (a lot of work depending on design)
4. Rasterize and engrave it that way? (If yes, do I do “dots”, “patterns” or “vary” and why would I change pattern density)

Also

5. What grayscale range do most people find works well? I’m guessing something like 100-70%
6. I assume it makes no difference which direction?
7. I am a little fuzzy (see how I did that) on defocus. I see .308 in the example, but I’m not sure what the material depth was. What ratio are people using relative to material thickness and does it matter if it’s “higher” or “lower” than the top surface to get the intended effect?

I’ve tried a few thing and get errors around using compound paths, gradient meshes, expanded gradients and the like, so figured I’d just ask the folks that have mastered this.

Thanks in advance!

(for reference, the SVG that I’m trying to figure out. As you can see, lots of independent parts… I think from a results POV I want to get the gradient to be continuous through the parts from bottom to top. For purposes of illustration in the photo attaached I did a whacky multicolor gradient to show how I’m approaching it and that any horizontal line is the same color. For the actual GF job, I understand this would simply be grayscale from X% to Y%)

[bapestar]

Here’s a shot at my first attempt. Did a bunch of testing with different levels on PG 3mm since it fit the base I had really well.

First one was 1000/Full/VP10min/225/.3" focus. The gradient was 60% black to 100% black (from bottom to top). It looks good - for my first attempt, but the bigger areas show a lot of texture, especially near the bottom. I think the hotspot at the bottom is likely just proximity to the lights and the amount of surface area, not that I did it too deep?

Tried again, this time going to 450 and 50-100% gradient. Doubled print time, but here’s what I saw - not appreciably better. Maybe a bit smoother, but still about the same kind of hot-spotting and a fair amount of visible texturing. (the hotspot at the bottom isn’t quite as pronounced as it is in the first photo)

My questions for the edgelit crowd

1. Is this “as good as it gets”, or should I continue to play with settings to try and improve? I know that I’m hyper-fixated on the detail right now - but hoping to find the bounds of what is possible as a new owner…

2. The right edge extent of the circle did not cut smoothly (unlike the rest of it). I didn’t pay attention as to whether or not this is where the laser started and stopped its cut (weirdly, the PG acrylic sheet I got was pretty warped - so maybe that’s it). There’s nothing whacky going on with my 11 point shape - simple arcs. I’m guessing there’s no way to manipulate start points? Open to other theories.

Thanks in advance… if cuts like this didn’t take 45 minutes, I’d have more time to fumble on my own.

[icandidesignsinc]

I thought the material height was the same as the focal height…how do u know how much to defocus by?

[pierce508]

Thank you so much for this information…worked like a charm for me! very helpful!!!

[raymondking32]

Glad that my past endeavors can still be of use!