All posts related to V2
By wimver
#381166
Hi,
I am working on an image which needs lots of waterdrops on a label. I do not succeed in making the water drops lighter than the surface on which they sit, normally a water drop catches light, and focuses it onto the surface, so that it appears brighter. see example on the cyan background.

I tried all kinds of Nd values, from 1.1 to 1.8, with no result about brightness change. only a bright rim appears with the higher ND values.
the attenuation is set to 10 times the size of a drop, so that is ok, and the transmittance is set to 255 white.
the shape of the drop is a perfect half sphere.
I tried placing the drops a fraction above the surface of the label, and also intersecting the label. the latter gave worse results.
is there a way I can make these drops brighter?
tnx
wim

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By Bubbaloo
#381167
1. Start with a good model. Water droplets on the side of a bottle shouldn't be modeled as half spheres. Look at the reference. They are affected by gravity (like boobies).

2. Next, good lighting is required. Look at the highlights on the reference compared with your render. Reference is most likely a studio photo.

3. Correct intersection. The droplet geometry will need to intersect the bottle surface, so that the ray travels like so: From light source -> through droplet surface normal -> bounce off bottle surface -> back through droplet surface normal again -> to camera. Keep in mind the bright spot you see in the droplets are bounced caustics, which require more CPU power.

4. Proper materials on bottle/label and droplets. The label material needs to be correct, because your bounced caustics reflect off of this surface. Use the wizard water material for the droplets. It's correct.
By wimver
#381185
Thanks Brian! I will immediately start looking for more reference material, like you suggested in point 1, last word ;-)

although I must say that the shape of a water droplet depends on the substrate it sits on (capillarity), I did some tests, and perfect spheres do exist in some conditions. small drops are perfectly round, the surface tension is stronger than gravity.

anyway, with your tips, I think I will get there.
By wimver
#381192
I made boobie type drops, intersecting the label surface, and used the water wizard. I rendered, but it looks very dull.

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the only thing I didn't do was changing the light, since I need sunlight actually. but I wanted to know if it would make a big difference, so I switched off sunlight and added a softbox. Much better! but it will take ages before the noise clears up...

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Will there be a Maxwell Render 6 ?

Let's be realistic. What's left of NL is only milk[…]