jwellery rendering in mental ray

[Agent X]

I am neither a MR nor jewelry expert, but my opinions are

a) A MR Nurbs trim approximation might help as the edges of your rings don't appear to be tesselated properly.

b) I think that you main issue is that you don't have any light illuminating th
e jewel. The jewels in the Maxwell are facing up, towards the main light source, so they are capturing the light. The most interesting thing about diamond, according to my fiancee, is how the sparkle in the light. Translated into useful information its the high index of refraction to causes diamonds to be interesting.

That is my two cents. It may also help if you posted some more information. Are you using Caustics, particular shaders, HDRi. It is hard to offer suggestions on improvements when i have no idea of what you have done.

[pwl]

hi,
Thanks for your suggestions..am not using any light for this scene, its lit by a HDRI image..i have attached the maya scene file, i would be very glad if someone can teach me how to use the shaders and light properly!

thanks in advance
maya scene file: http://www.waterlemon.co.in/jwellery.rar

[Agent X]

I have downloaded this scene and had a quick look. i will look into it more, but my clients are pissed at my renders, but a few issues i can see are:

a) each stone is not one mesh ( it is made up of man seperate meshes). In my experience, using the mia-x materials for pools, the difference between using a flat plane and a cube is definately noticable. so select the faces( the are all in one group luckily), Mesh > Combine
switch to vertex mode (F9)select all the verts and edit mesh > merge. this should helpwith refraction...

b) Refraction. Your IOR (index of Refraction) is 1.5. Diamond is 2.149 or around there.

c) The HDRi isn't very interesting. Think about how a photographer would light the diamond. i would look into how they light cars. i think the principles should be the same. Mess around with the set up.


I havea thursday deadline. So if no one has helped by then, i will have a go and post back.

Good luck. Remember, the diamond can only refract the light in the scene.

[Bitter]

Keep in mind that you also need a way to show the diffraction like the diamond in the maxwell render. Daniel Rind has an older fake diffraction shader online. It can be slow so take care when tweaking it.

http://animus.brinkster.net/downloads/Diffraction.zip

Master Zap also has a way to similarly fake it with some mia shaders.

www.mentalraytips.com (http://www.mentalraytips.com)

[pwl]

I have downloaded this scene and had a quick look. i will look into it more, but my clients are pissed at my renders, but a few issues i can see are:

a) each stone is not one mesh ( it is made up of man seperate meshes). In my experience, using the mia-x materials for pools, the difference between using a flat plane and a cube is definately noticable. so select the faces( the are all in one group luckily), Mesh > Combine
switch to vertex mode (F9)select all the verts and edit mesh > merge. this should helpwith refraction...

b) Refraction. Your IOR (index of Refraction) is 1.5. Diamond is 2.149 or around there.

c) The HDRi isn't very interesting. Think about how a photographer would light the diamond. i would look into how they light cars. i think the principles should be the same. Mess around with the set up.


I havea thursday deadline. So if no one has helped by then, i will have a go and post back.

Good luck. Remember, the diamond can only refract the light in the scene.

Hi,

Thank you for taking a look at my scene, the model of the ring was done using rhino, every triangle of the mesh was a seperate object when i imported into maya, so i have to group them seperately (it was so tedious)...I will try merging them as you suggested.

The shader i used was the 'thin glass' preset of the mia x material, i tweked its value to get tht result, but i have very little knowledge about the attributes in the shader. I hav used IOR 2.4 in my next scene (s2.mb)..

anyways i will try try tweaking with diffrent light setups and HDRI..I will post the result very soon but you take a look when you are done with your project :)

good luck for your project and thanks for your very timely help..

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