[emarvets]

I have read through the forums for jewelry and gemstone and have found plenty of threads, but they are older. Any links for files or to tutorials are now dead. I am struggling. Can anyone point me to a tutorial that is jewelry specific?

Several members have pointed to the following link. I know it and have been using that practice succesfully for actual jewelry photography for many years prior to purchasing Maxwell:

http://www.tabletopstudio.com/documents ... graphy.htm

In photography, when I use a sparkler light, a diamond returns fire (pinpoint reflections of color). However, in Maxwell my diamonds all sparkle white light.

[JDHill]

Have you made sure to enable Dispersion in your diamond material? You'll find the switch for this in the global material properties, as described here.

[emarvets]

Yes I am. I am using the diamond_complexIOR for my material.

[JDHill]

There is also a global Dispersion flag in Maxwell Render itself (see the Globals section here), is that enabled?

[emarvets]

I could not find that option in the Rhino plugin, but I did find it in the Maxwell Render interface and it was not selected.

Is there a way to enable global dispersion by default? Is the option available in the Rhino plugin?

[JDHill]

That one has not yet made it into the plugin UI, but you can enable it by putting -dispersion:on in the command-line field. If you want to make that the default, you can use Presets > Defaults > Store Current in the toolbar of the Scene Manager > Output page.

[emarvets]

Thanks, I have color in my diamonds now.

I bought Maxwell because I was really impressed with the gallery.

After reading the manual, doing the tutorials, and playing with it for a month, I've come a long way. But I'm missing something. There are no strictly jewelry tutorials and I really wish there were. The forums have had a lot of jewelry topics, but they are all older and hard to follow since the links to files are now dead. I'd really appreciate any help getting me farther down the road because I've hit a plateau. This is where I am:

[Mihai]

I think from now on it's not a matter of Maxwell specific tips but you should instead look at some jewelry photography setups/tutorials. Such as:
http://www.tabletopstudio.com/jewelry_p ... html#focus

There is a section there called "How to add sparkle to diamonds or faceted gemstones" and they show a few types of light for doing that. To mimic that type of light in Maxwell, it would be best if you had access to a real lamp like that, and photograph it using different exposures to then create an HDR photo of it. Then use that HDR applied to a plane to create an image emitter. After that it's all about careful placement but FIRE can help there a lot. There is also HDR Light Studio which has some hdr photos of lights included and it's a great application for these types of lighting: http://www.hdrlightstudio.com/hdri_light_packs.htm

http://support.nextlimit.com/pages/view ... Id=1475757

Another way to mimic an array of small lights efficiently is to instead create a black and white mask in an image editor and apply that as a Layer mask to your emitter material. About Layer masks: http://support.nextlimit.com/display/ma ... ing+Layers

So this way you just apply this material also to a flat plane, but areas in the Layer mask which are black will be invisible so you can create very quickly from a single piece of flat geometry something that looks like an array of small LEDs by creating small white circles in your layer mask image.

[emarvets]

Are there any libraries of HDR lamps that people share? Do any come with Maxwell?

I watched all the tutorial videos and took notes on HDR Light Studio thinking it was part of Maxwell only to find out it costs another $500. If I was doing a lot of different things with Maxwell, I would save up to get it. I just need a single lighting setup to take pictures of my jewelry CAD models.

Why would I use a layer mask instead of just creating an OpenEXR and using it as an emitter?

[hatts]

HDR Studio is not necessary, all it does is expedite the process that any 3D app can already do (putting X emitters in Y locations). There are many usable (free) "light box" HDRIs out there.

Judging by your attached image it looks like your modeling is definitely not the problem; you've got nice subtle fillets etc. Also I'd say you've gotten the diamond looking great with regards to dispersion and general look.

I would consider adding the slightest of bump/scratch/dust maps to some of the metal parts. I know jewelry is well-crafted but nothing in reality is so perfect it doesn't have a little surface inconsistency.

Also, for this shot, you're using the HDRI in a way that maximizes boredom. The camera angle is centered and the HDRI is centered, with one broad light source that evenly washes across the ring. Try some combo of off-center camera angle and/or rotated HDRI and/or wackier HDRI.

I think one good technique for lighting of rings specifically is to position the HDRI in a way that places a large black void across the ring's body. In your shot the blackest part of the HDRI is hitting the little mounts that hold the gems, whereas I think it might be more effective hitting the ring's body.

Furthermore don't be discouraged by the time it's taking you to learn Maxwell. A month in the game is nothing; it took me roughly a full year to be truly confident and productive with it.

[emarvets]

Where is a good place to find free hdri's? Bump maps?

A month is not a long time, but I've hit a plateau. I'm not improving and I've run out of manuals and tutorials.

I model in Rhino and ensure my stones and metal are not intersecting. Then I send the metal into 3DCoat to smooth my meshes before rendering (it is also useful for fixing boolean fails). All the subtle fillets are added with a couple of clicks in about 5 minutes.

As far as composition, I usually clone the object and have them lay against each other so you can see contrasting angles of the piece I'm rendering. I used a boring layout just to work on my light box setup.

I have a left, right, and top emitter that are plain emitters with different temperatures. The front of the light box is open with another plain emitter behind the camera. When I add a sparkle light (small, hidden, image based emitter placed directly over the stones), it washes out the diamonds before adding additional color, or what a jeweler would call fire. I've tried several kinds of OpenEXR's I've made in Photoshop. This was the last one.






I have all the emitters turned way up and use multilight to adjust them after the render is done.

[hatts]

That sounds like easily a good enough workflow. For me the last large improvement that could be made is to not have so much gray reflected in the ring's body.

[Polyxo]

If you use 3DCoat you have everything at hand. You can remesh when converting stuff to Voxel or in any case redo UV's
so that you are no more bound to the original Nurbs patch structure. You also could quickly draw a specular map for the metal
and a very subtle normal map. Pressing the 1 and 2 key lets you work with control on these isolated channels.

[emarvets]

Mathew, I think a bump map would take care of most of that. It looks like the black and grey are shading from full and partial shading. I'll start investigating making one if no one has one they can share.

Poly, I only know how to do a few things in 3DCoat. Are you saying that it's easy to adjust the mesh and achieve the same effect of a bump map in Maxwell to get a more realistic surface? Wouldn't I be better off with a bump map, since it would be saved in my material for future use and let me work with less dense meshes?

[Half Life]

Mix in bit of anisotropy for the metal parts -- this occurs naturally with polishing: http://www.maxwellrender.com/forum/view ... 82#p337382

Best,
Jason.