[Hans-eirik Hanifl]

I just had a similar problem the other day and what I ended up having to do was render out as a image sequence and it got rid of the stutter. I can’t take credit for this fix however as I found the solution here https://www.adobeforums.com/webx/.59b581e8 they had some other ideas posted but I stopped when I found the image sequence worked for me. Hope this helps

[Hans-eirik Hanifl]

Ok the file has been up loaded to:
https://hanifl.com/cow_upload/water_rays.aep <-- AE file https://hanifl.com/cow_upload/caustic_settings.jpg <-- caustic generator settings https://hanifl.com/cow_upload/Underwater_Statue.jpg <-- background image I didn't upload the caustic animation as it was a 120MB image sequence and it's faster to explain how to create it. Go to https://www.lysator.liu.se/~kand/caustics/
the caustic generator is a free program. I have uploaded a screen shot of the settings I used in the generator, it’s a super easy program to use.
Only other thing you need to make this work is the plug-in shine which is applied to caustic image sequence layer named cs_[001-120].bmp

One you generate out your caustic image sequence just import it into the project, select the caustics layer in the comp then holding down alt on a PC or option key on a mac, click and drag the new image sequence on top of the old layer. It should replace the layer but retain all the settings of the old one. Hope this makes sense if not repost and I’ll clarify myself. G’lucky

[Hans-eirik Hanifl]

Wasn’t exactly sure what you wanted but I took my best guess and threw this together for you.

I couldn’t find a image looking straight up into the sun underwater but the principles are the same.

https://hanifl.com/cow_upload/2up_underwater.jpg <-- 2up before and after image. https://hanifl.com/cow_upload/underwater_lightrays.mov <-- 5mb animation The shine is applied to caustic animation that is turned into a 3d layer and then rotated into proper perspective. The volumetric rays are masked solids with a wiggle expression applied to the opacity to give it a more underwater feel. Only difference between this perspective and looking straight up I would probably use more perspective shine layers to make the rays shoot off each side. Hope this is helps. If you want the AE file to look at I can upload it. Just let me know.

[Hans-eirik Hanifl]

I would suggest drawing out your line and arrow on one solid and then create another solid above the first (call it arrow_reveal or some such), on this second layer draw the path you will use as a stroke (make sure when you apply the stroke that it is wide enough to cover the line and arrow). Then set the trackmatte of the arrow layer to Luma Matte of the “arrow_reveal” layer.As the stroke is applied it should reveal that line and arrow beneath as if it is being drawn on. You can always precompose these two layer together so that you can use them in a 3d space.