OTOY Forums

Hey Guys,

Working on adding water droplets to a sphere by displacement.

The base sphere mesh is has a regular glossy material applied.

I then have a second water mesh with a specular material applied. I displaced this and then added an alpha channel to knock out the remaining area where I dont want the water...

Both meshes are the same size and I'm getting some weird interference from the plugin. Not sure what to do here but I've attached screenshots.

When I make the water mesh larger than the base mesh so its not touching I get no issue but now the drops are floating.

I guess what I am asking is there another way to accomplish this so the meshes arent having this kind of interaction.

Any help is appreciated! Thanks.

Try setting the Kernel->Ray Epsilon to the lower possible value it will go to.

Paul

Thank you for the reply Face.. The meshes still seem to be interacting still @ Epislon .0001 - that's about as low as I can go. I found a post yesterday where someone was able to achieve a really nice result with displacement.

Ive contacted them but no reply quite yet. Here is a link to the post: viewtopic.php?f=9&t=48591

Made another attempt today.

This time I used a single mesh and a mix material.

The geometry errors are gone but Im still getting these dark halos around the water drops.

I think Displacement |Image files can only have the UV projection, and spherical projection won't work - but I'm not 100% certain on that. Also, I'm not sure how well mixing a specular with a glossy material will be. I think you would get a much better result with two meshes - one being the specular material with the droplets and have it being .01 of a mm bigger than the inside mesh. This will also more closely match real-life.

Happy to experiment if you send me the droplet texturemap.

Paul

Thanks again for the reply!

Gave the UV mapping a shot which produced a slightly better result but still getting some interaction when the drops get too close to the base. The drops get a bit floaty when I push them away from the base to combat the issue.

Ive included my drop map that was made in photoshop along with a screenshot of my latest attempt.

I did it with 2 spheres....

Sphere 1 = 100% scaled, with the green material
Sphere 2 = 101% scaled, with the Displacement material
Set Ray Epsilon to 1um

Scene attached.

Paul

Thanks again. I tried the double mesh again and am getting this thing pretty close. I still am having an issue because the drops look like they are floating when you look around the edges. This will end up being used for a client so it needs to be perfect. Is there any we we can solve this?

I've really sorry - but this is getting out of my field of expertise. I suspect you just need your opacity map to have the drips a little bigger - however they may be other ways. There are quite a few renders in viewforum.php?f=5 with drops on bottle. Suggest scanning through the gallery and see if the creators detail their workflow.

Also, if you scale up your scene x 100, you can have the drop mesh much closer to the base mesh before hitting the ray epsilon limits.

Sorry I can't be more help.

Paul