OTOY Forums

Hi all

I really hope someone can help me with this as im going mad. I have a simple can that im adding condensation to and whilst ive more or less got the look i want when i render it out im getting a white halo thing going on round the bubbles that particularly sit over the white areas of colour. Ive tried to use direct lighting although I prefer PT for this and I have fake shadows turned on. Without that it doesn't look great. Ive also played around with the specular settings but it never gets rid of the white im seeing around the bubbles. Can someone please help?

Ive attached a couple of screen shots and a simple version of the file.

Thanks
PG

Anyone?

I think the problem is in the shape of your geometry; you are using perfect spheres, resulting in almost perfect hemispherical droplets. Only very tiny droplets are close to that. Try squashing them down to about 1/2 as thick as they are tall and wide, and embed them slightly more into the surface. I also noticed your index of refraction is high at 1.5, try taking it down to 1.33 or so.

Thanks for your reply frankmci.

I tried what you suggested (see attached new file) but its still doing it and in fact it now looks like the smallest are also doing something odd and look like they now have black outer key-lines. This issue just seems to be when they're placed over lighter colours. When you look at the bubbles over the black areas they dont seem to interact in the same way. This doesn't of course change the fact that I may have to use this effect in the future on lighter materials so I need to find a way to get round this problem.

The halos are definitely within the condensation bubbles so would I be right to assume its something to do with the spec material itself? Perhaps an absorption issue??

Further help will be appreciated.

Thanks
PG

You may want to increase your specular depth. I have found that can work in situations such as this.

Thanks jayroth.
Yeah I had tried that in the first place the upping of the specular in the settings. It does work for things like the black bits you can sometimes see through spec materials but for this unfortunately doesn't help. What I have found now that does help a bit, and I mean a small bit. If I lower the index to say 1.2 it starts to look better and less pronounced. This obviously may not be correct but im not sure how else to get around it?

Perhaps try a Cinema 4D volume object to model the condensation instead? That could get your geo closer to reality and allow Octane to do its thing. It looks like a caustic effect to me. If you change the lighting direction what do you see? Also, have you tried your setup with a simple plane instead of a cylinder and see if the issue persists?