[eric nixon]

Here is an example with a twin bsdf & flipped normals, (very fast to render, there is no displacement). In this example the drops are mapped onto both sides of the simball, which makes it a little harder to see whats going on...



I'm quite curious how you dealt with the boolean of the large drops onto the glass surface. Is there any trick to it?

[simmsimaging]

There is no boolean - I just scattered geo drop using FPP and let the chips fall where they may with the interpenetration That's why some look better than others: there is some random variation in the depth of penetration so the refractions (and caustics) vary - or so I theorize anyway.

Be nice to see your droplet material on a solid to get a better sense of how it works. I can't really tell in that example - there it looks more like dimpled glass to me.

/b

[eric nixon]

[simmsimaging]

Yeah, that is clearer - thanks.

It works okay for the really small stuff, but IMO not well enough for anything that large. The only stuff normal mapped in my image is the stuff so small it almost reads just as dots of light. Anything where the core of the drop is visible is done with geo. I prefer it that way, although yours would certainly work well for lower res or more distant renders ( or flat-on view too for that matter)

b

[eric nixon]

Also a better normal map would help, this one doesnt 'pop' off the surface its more of an undulation.

Maybe a real flow water drop plugin is needed, esp to get convincing animated drops. And a revision to the way maxwell handles interpenetration would help here..... one day it will be solved...

[renbry]

When I did the Leggos pasta ad I used a duplicate surface with a special material which displaced the water droplets to create the 3D surface for refraction/caustics. It was the only way i could produce correct looking droplets.

I made a maya procedural material which made the water droplets (3d texture) and baked them to disk as high res images. Two images per object; one for the greyscale displacement and an alpha channel derived from the procedural (visibility of water substance)
These two maps go into a maxwell material with the water preset, then displaced with the greyscale and layer mask with the alpha to cut out water from where it is 'dry'

It worked perfetly, because it started as a procedural shader I could bring 'wet' assets in, soak them and bake out two maps very quickly. Then assign the Maxwell material and swap maps out and it was ready to go.

The only issues were software based at the time, i.e I may not have been able to instance an object and displace only one of them; or It may not have worked with external mxs objects...etc etc. Ultimately i think those bugs have been fixed since.

Here is the original post i made about the spot and FYI - the only live action shots in the ad are the most macro ones (maybe ~5 of them)

http://www.maxwellrender.com/forum/view ... 15#p352580

Cheers,