UV Mapping

Chad Holton · October 31, 2016, 07:39:06 AM

Quote from: mertmg on October 31, 2016, 05:41:54 AM
why don`t we have a detailed tutorial regarding to creating a UV map for Keyshot? i can`t make it work

What modeling software do you use? There is usually tutorials regarding UV mapping in more common 3D programs (if they support this type of mapping). Once the UV map is created and model is exported, you just choose this mapping type in KeyShot.

DMerz III · October 31, 2016, 08:19:20 AM

mertmg, I've been trying to figure out UV mapping for a LONG time now, haha, so I understand your pain. In the past few months, I have discovered why it is so hard to get a straight answer with Keyshot. Basically, it is highly dependent on your modeling/CAD software, and your process.

I'll do my best to explain as a "newbie" in this area. Here's what I've gathered, and if someone who is an expert can help clear up any misunderstandings I have, please feel free!

If your method to model something is polygonal modeling (like in 3DsMax or C4D, Maya, etc.) you'll have more success finding answers about UV Mapping, and the tools you'll need to "set the UVs". These programs have a built in UV editor, and there's an entire process for how to "unwrap" the UVs for proper texture mapping. Each one does it differently, and there are other programs out there that make the process more or less, "easier". Search for tools like Headus UV Layout, 3D Coat, 3D Unwrap.

If you're modeling using CAD/NURBs type software, Solidworks, Rhino, MoI3D (which is what I've been using), you're going to have some trouble when you get to unwrapping the UVs. UVs rely on a mesh to make sense of coordinates, and even though you can export from these NURBs programs into a polygonal mesh file (like an OBJ) when you look at the mesh, it's not optimal for unwrapping. There's something called "edge flow", which I am just starting to understand and modeling with proper "edge flow" in a polygonal modeler is something that must be thought of beforehand.

But what if you're designing something in NURBs? What's the solution? Well, I am still trying to figure that out, but I wanted to share my experiences in what I've learned in my search to figure this problem out myself as well.

From what I've gathered, there is a way to "retopo" a model, and perhaps have a better polygonal mesh more suited to UV Unwrapping, but I haven't made it far enough to understand what workflow/programs I need to achieve this. Really hoping someone else can lend some advice to us both!

mertmg · October 31, 2016, 09:41:48 AM

HI dimerzii,
i use Creo/Solidworks so I`m on CAD/NURBS. i understand complexity of it but i`m really willing to have an answer to it like you. i`ve attempted in several difference ways to render related textures/labels onto my products it worked well but i struggle as my needs getting bigger and bigger. UV mapping is the simplest approach in an ideal world but having models from CAD and trying to align them with polymeshes creates the problem. i`ve tried to install Blender and give it a go but it didn`t end up with pleasure so i`m looking for more. i`ll have a look at your recommendations but i`m sure there is a way achieve this even though it is too complex

Quote from: dmerziii on October 31, 2016, 08:19:20 AM
mertmg, I've been trying to figure out UV mapping for a LONG time now, haha, so I understand your pain. In the past few months, I have discovered why it is so hard to get a straight answer with Keyshot. Basically, it is highly dependent on your modeling/CAD software, and your process.

I'll do my best to explain as a "newbie" in this area. Here's what I've gathered, and if someone who is an expert can help clear up any misunderstandings I have, please feel free!

If your method to model something is polygonal modeling (like in 3DsMax or C4D, Maya, etc.) you'll have more success finding answers about UV Mapping, and the tools you'll need to "set the UVs". These programs have a built in UV editor, and there's an entire process for how to "unwrap" the UVs for proper texture mapping. Each one does it differently, and there are other programs out there that make the process more or less, "easier". Search for tools like Headus UV Layout, 3D Coat, 3D Unwrap.

If you're modeling using CAD/NURBs type software, Solidworks, Rhino, MoI3D (which is what I've been using), you're going to have some trouble when you get to unwrapping the UVs. UVs rely on a mesh to make sense of coordinates, and even though you can export from these NURBs programs into a polygonal mesh file (like an OBJ) when you look at the mesh, it's not optimal for unwrapping. There's something called "edge flow", which I am just starting to understand and modeling with proper "edge flow" in a polygonal modeler is something that must be thought of beforehand.

But what if you're designing something in NURBs? What's the solution? Well, I am still trying to figure that out, but I wanted to share my experiences in what I've learned in my search to figure this problem out myself as well.

From what I've gathered, there is a way to "retopo" a model, and perhaps have a better polygonal mesh more suited to UV Unwrapping, but I haven't made it far enough to understand what workflow/programs I need to achieve this. Really hoping someone else can lend some advice to us both!

TpwUK · October 31, 2016, 04:05:58 PM

My apologies guys, I have had a lot of personal stuff going on in my life since this pledge was made, I will try and get round to this before the New Year, hopefully the issues I am facing will be resolved by then.

Martin

DMerz III · November 01, 2016, 01:45:03 PM

Martin, there's no need to apologize! However, when you do get a chance to make that thread, I AM VERY INTERESTED!

I've learned quite a bit about it just from trying to solve a simple problem of needing a bitmap to wrap around an organic "cord" that I modeled in MoI3D. I'm new to modeling, and MoI was the easiest program for me to learn, however, not the best choice when you need to texture something with UVs. I've been playing with Headus UV Layout (haven't made the purchase until I know for sure it can solve my problem). I suddenly had a breakthrough when I modeled the cord in c4d instead, and unwrapped it in 2 seconds using UVLayout. It's all about those quads! Now...if you've got a workflow from MoI to UVLayout, I'm super super excited to see what you've got.

PS. The image you posted at the beginning of this thread explains the problem precisely.

DMerz III · January 05, 2017, 01:13:47 PM

Martin, I'm curious, have you ever used 3DCoat?

I've seen some tutorials by Chipp W, in which he takes a MoI3d hard surface model, does some "3d-painting" with 3DCoat, then exports those maps into Keyshot, and everything seemingly lines up.

https://www.youtube.com/watch?v=lk_6SsRfmAg

What I haven't seen is someone take a Moi OBJ export into 3DCoat, retopo, uv unwrap, and then export that OBJ into Keyshot, but my inkling is that it is possible. (I do not have 3DCoat yet, but would love to purchase if I could find someone who knows THIS workflow could be a reality).

TpwUK · January 05, 2017, 02:58:03 PM

Quote from: dmerziii on January 05, 2017, 01:13:47 PM
Martin, I'm curious, have you ever used 3DCoat?

I've seen some tutorials by Chipp W, in which he takes a MoI3d hard surface model, does some "3d-painting" with 3DCoat, then exports those maps into Keyshot, and everything seemingly lines up.

https://www.youtube.com/watch?v=lk_6SsRfmAg

What I haven't seen is someone take a Moi OBJ export into 3DCoat, retopo, uv unwrap, and then export that OBJ into Keyshot, but my inkling is that it is possible. (I do not have 3DCoat yet, but would love to purchase if I could find someone who knows THIS workflow could be a reality).

I couldn't get on with 3D-Coat I found it all very unintuitive. I know it has some excellent tools for sculpting and painting and the retopo tools are considered to be some of the best in the world so it's auto UV generation is supposedly really good too, however I could not get over the interface and struggled like hell with it, you might find it easy so I would suggest playing with the trial and see how you go.

I did start writing my theory for beginners to UV mapping that I wanted to complete before Christmas but sadly my wife was forced to go into a care home by the powers that be, and sadly that means I have been too distracted and don't have time to complete it for now, but I will happily post what I have written up to now if you think it might help you understand things a little better.

Martin

DMerz III · January 05, 2017, 03:13:42 PM

Martin, very unfortunate to hear about your wife's situation. $:-\$

I cannot imagine the difficulty in that process. Hoping the circumstances shift in a positive manner soon, man. Thanks for all your help here and elsewhere on the forums. I see your posts often, and they're always very informative; much respect.

Either way, do not mean to rush you on your informative theory to be. If anyone else does have some insights on 3DCoat or other techniques, it'd be greatly appreciated! (otherwise, we'll be trying out the demo version soon!)

Here's our situation.

We're encountering a potential need in the near future to figure out a solve for UV mapping. Unfortunately, many of our models are provided to us via CAD, and we do our best to work around those limitations. Most of the time it doesn't need UV mapping, but for a particular part, we're going to need a solve for it soon. It's a bit more complex and unfortunately, not a part we can just remodel ourselves in a timely manner with a polygonal modeler.
Not to mention, we need it to be accurate. So my hope is this hunch with 3DCoat might be the solve we're looking for.

Anyway, thanks again Martin, feel free to share what you have, but totally understand if it's not ready to share yet!

TpwUK · January 05, 2017, 04:51:01 PM

Quote from: dmerziii on January 05, 2017, 03:13:42 PM
Martin, very unfortunate to hear about your wife's situation. $:-\$

I cannot imagine the difficulty in that process. Hoping the circumstances shift in a positive manner soon, man. Thanks for all your help here and elsewhere on the forums. I see your posts often, and they're always very informative; much respect.

Either way, do not mean to rush you on your informative theory to be. If anyone else does have some insights on 3DCoat or other techniques, it'd be greatly appreciated! (otherwise, we'll be trying out the demo version soon!)

Here's our situation.

We're encountering a potential need in the near future to figure out a solve for UV mapping. Unfortunately, many of our models are provided to us via CAD, and we do our best to work around those limitations. Most of the time it doesn't need UV mapping, but for a particular part, we're going to need a solve for it soon. It's a bit more complex and unfortunately, not a part we can just remodel ourselves in a timely manner with a polygonal modeler.
Not to mention, we need it to be accurate. So my hope is this hunch with 3DCoat might be the solve we're looking for.

Anyway, thanks again Martin, feel free to share what you have, but totally understand if it's not ready to share yet!

These are just drafts and are only one page each so won't take long to read, I will try and muster some time over the next few days and cover CAD models and the processes you can take to separate and trim to help with texture mapping.

Martin

DMerz III · January 06, 2017, 01:49:46 PM

Thank you Martin, much appreciated, going to take a look at these RIGHT NOW!

TpwUK · January 11, 2017, 09:52:51 AM

Quote from: dmerziii on January 06, 2017, 01:49:46 PM
Thank you Martin, much appreciated, going to take a look at these RIGHT NOW!

Part 4 added to the list above - I will write part 5 when I get the chance, hopefully over the weekend if not before.

Martin

DMerz III · January 11, 2017, 11:54:28 AM

Thanks again Martin, these are very well written and concise. Definitely helps one get a grasp of the complexities of the problem!

I do have some interesting news for anyone looking for a short-term solution. I downloaded the free 30-day demo of VRED Pro just to try to see if their new UV Editor worked as advertised (see video attached). They claim it will work out unwrapping for meshes produced from NURBs modelling programs.

It took several hours of trial and error, but I was able to get a good result on a rounded cube like surface shown earlier in this thread from a surface originally modeled in MOI3D. Unwrapped the OBJ in VRED, then exported another OBJ, which I was able to map a 2D texture seamlessly in Keyshot.

Helpful hint for anyone who wants to try it out themselves. I followed the steps in the video, however I also used the "Unwrap Islands" button several times afterwards in order to "straighten" out the flattened mesh. At first it was bending over itself, so several dozen "clicks" on the "Unwrap Island" button helped untangle it for me. (Also note, you'll need to select the island in the UV editor by holding shift and dragging. This took a while for me to discover, so I thought I would help anyone wondering.

I also tried to get a result from 3DCoat using another free trial, but wasn't able to get a "seamless" texture to wrap over a rounded cube in Keyshot. I'm sure it is due to a lack of understanding on my part, and not that it is incapable of doing so, VRED just made the problem a little easier to solve, albeit, after many hours of trying. (if I were doing 3D 'painting', 3DCoat, solved that issue in seconds).

The only problem is, I cannot afford VRED, and my trial will be over in just a couple of weeks. We do not run into this UV problem often enough to justify getting a subscription. SO HOPEFULLY LUXION CAN INCORPORATE THIS INTO KEYSHOT SOMEDAY! =)

DMerz III · January 11, 2017, 12:24:24 PM

I feel like that was a lot of text, and no pretty pictures. So I redid my process using a simple rounded surface from MOI3D very similar to the shape I had originally worked with.

1st Image is MOI3D surface modeled (NURBs)
2nd Image is OBJ export out of MOI3D (triangular mesh, which works Keyshot import later).
3rd Image is in VRED (the texture is a UV Checker map to show what you are dealing with before the unwrap process).
4th Image is after the Unwrapping technique in VRED, you can see, it isn't perfect, but pretty good for my purposes.
5th Image is the Before (in front) and After (in back) using a procedural polygon diffuse map. The materials are linked, exactly the same, mapping mode is obviously UV.

Hope this helps!

TpwUK · January 11, 2017, 01:55:36 PM

Looks pretty impressive - How responsive is VRed these days? I found it very slow when I tested it, even with 24 cores on Xeon v2

Martin

DMerz III · January 12, 2017, 08:04:49 AM

It is only my first time using it just this week, but it seems fairly responsive. Granted, I've only been using it to UV unwrap this ONE object, and haven't used it for anything else it is actually supposed to do. (I'm also using a pretty beefy Dual XEON E-5-2660 v3 cpu machine with 64GB ram.)

I'm also pleased we finally found something that could actually solve this major issue. Unfortunately, we won't be buying a license because we just don't have a need for VRED otherwise, and UV issues don't arise with every job, just once in a while, and always a pain since we're receiving the CAD from different sources every time.

It does give me hope that there is now a piece of code out there that makes this possible.