Best practices for 3d asset modeling suggestions?

abomb · June 29, 2014, 11:43pm

I have been lurking this forum and soooo many tutorials on unreal and related tools & techniques. I have not come across one that addresses this though.

I was really trying to study the sci-fi hallway example to learn how they did everything, specifically the models & assets used. I noticed that a lot of the environment is what I would call “Cheated”. Essentially a piece of paper with a texture applied. I know this may be over simplifying it and I am sure they made it solid when they were modeling it… My question is HOW do you model like that? I would assume these types of models are way easier to uv unwrap!? I have some ideas but I am not sure what the best way to go about it is. The Hourences solus project guy had a bunch of assets like I am thinking. What I would think is you kind of model it solid then cut out the back facing faces…

I model mostly in Rhino3d which isn’t THAT friendly for unreal engine but I have had small success so far… I also have blender & zbrush but have not learned it to where I would feel comfortable modeling within the programs. I don’t have the privilege of owning or accessing 3ds max or maya but possibly the techniques in that program could probably translate.

Any advice or tutorial links to how stuff is made for games? I would need to know best ways to model like that for performance or whatnot. Also I really don’t quite understand the second uv for lighting. If you create your first UV with no overlapping, couldnt you just use the same UV? I noticed in the sci fi hallway there were some with overlapping UVs which i thought were a no no. I could probably replicate the scene in rhino fairly easily but, I have never textured stuff before, and everything would be solid and probably somewhat high poly when I get it into UE4. Also rhino’s unwrapping is not friendly at all. blender looks so “easy” you just mark the seam on the edge, but in rhino not every edge has an option for a seam which is kind of ridiculous.

Also anyone who happens to have good advice on converting rhino nurbs (or nurbs in general possibly) models to a suitable polycount or whatever to use for this engine i’d love to know that as well. I also attached two practice items I have made. The railing i modeled after the realistic rendering example just to see if rhino could unwrap properly. It was my very first time even unwrapping anything so it was bad. I made it too quick so there was a mistake or two in there :P. If anyone could take a look at these and tell me if what I am doing is working/suitable.

file: Google Drive: Sign-in
reference images - added unlit version the first picture was so dark oops.

SimpolJosh · June 30, 2014, 3:47am

I think you should look into polygonal modeling in a package like blender. I think it will give you greater control of how your asset turns out in-engine. When modeling directly with polygons nothing has to be “created solid.” A wall can be made (and often is) as a single plane right from the start. Also yes you can get away with having a single UV layout for your lightmap, however; that would lead to inefficient use of texture space. You want extra spacing between UV islands to prevent shadow bleeding in the in the lightmap. This is because there is normally a massive resolution discrepancy between the textures and the lightmap; lightmaps are typically a much lower resolution image so your UV islands need more empty space between each other. Overlapping UV’s is normally allow separate UV islands to use the same texture data. This is an intentional technique and should not be confused with issues caused by strange badly unwrapped meshes where a single island is overlapping itself.

P.S. that DNA ring is awesome.

Edit: This is a good place to start if you want to learn blender and get into poly modeling. I feel like Andrew Price is a good resource even if his focus isn’t in games particularly (generally creates finished renders). You can learn some of the basics about subdivision modeling and texturing from someone I find informative, friendly, and entertaining.

I’m going to attach some pictures of a project I am currently working on in Blender and if you have any questions in particular about its creation I will do my best to give you answers. The images are of a high poly subdivision surface model. When it is complete, I will create a low poly version and the details and surface normals will be projected from the high poly model to the low poly.

-Josh

SonKim · June 30, 2014, 4:19am

@abomb, cheating is allowed in game engines and compositing software - so keep cheating!Actually they “cheated” they used nDO for most of the stuff in the SciFi hall way. You can model all this stuff and bake it to a polygonal plane as you mention but it would be faster to just use nDO for that sort of stuff because your time as an artist could be spent on more meaningful aspect of a 3D environment. In the real world in a game studio no one cares how you get from point A(model everything or use nDo) to point B(finished work), they want quality work as fast as possible. Also if you want get a job at a game studio learn Max/Maya(because they are industry standard) but if that’s not your long term goal use which ever software you like, yup it’s that simple! Rhino is nice though a bit expensive - I used moi3d(because it cheap and awesome). Software like Rhino/Moi3d have their place you can use them to create high resolution hard surface model in many cases a lot quicker then a traditional polygonal/subdivision surface app, those are good for modeling the low res mesh,UV,smoothing groups. I was still learning moi3d and I manage to make this SCAR: http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=5157.1

Yes I believe in UE4 you can use the first UV map for Light Mass if there aren’t any overlapping UVs, there are some trade off but that’s for another thread. UV/Texturing is something you’ll need to do in a traditonal polygonal modeler I use Modo it has some awesome modeling & UV tools! You can use Rhino/moi3D to create your high res mesh, export that out via FBX as a polygonal mesh(you can do this in moi3d , not sure about Rhino), then you need to create a low resolution mesh base off of that high resolution mesh(this is known as “retopology”) - you’ll need a traditonal polygonal modeling app for this(not NURBS). With the High res and low res mesh ready you’ll need to bake a normal map(The Fundamentals of Perfect Baking - YouTube). I use Xnormal for baking it’s got tons of useful outputs. You’ll also need to texture your mesh, check out Quixel Suite and Substance Painter & Substance Designer.

nDo: nDo2 workflows #1: Creating hard-surface designs - YouTube
Everything you ever wanted to know about normal maps and some: http://wiki.polycount.com/NormalMap/

I do have one baking advice for you regarding UE4, if you have any hard edges(edges that have a 90 degree turn) you’ll want to split the UVs at those edges. A good example is a cube, all edges are sharp 90 degree. If you don’t do that you’ll get normal map rendering artifacts in UE4:Normal Map Workflow with Xnormal is not working - Programming & Scripting - Unreal Engine Forums At least until Handplane3D supports UE4…

There are tons of video on youtube on content creation aspect of game development, but yea you can still keep Rhino in your pipeline if it can be exported to a polygonal modeler(i.e. Modo,blender,Maya). Lots of videos on retopolgy, texturing, UV mapping,etc once you understand it you can apply that knowledge to any other 3D app.

SimpolJosh · June 30, 2014, 4:56am

Funny that we both used a SCAR as an example! lol. Very nice model. Mine is using polygonal modeling and is clearly not done though

SonKim · June 30, 2014, 5:16am

Yea I got the idea from you :P.

**@abomb **- One important advice on the low res asset aside from keeping the triangle as low as possible. The next best thing you could ever do is to check out your low res asset silhouette, you can apply a pure black material to it and start rotating it. This can reveal how will you asset is built and what areas need to be rework. You want to make sure you are 100% happy with your low res asset before you start UV unwrapping it.

Denny · June 30, 2014, 9:42am

Wiktor Öhman, also known as Disting, is the guy who was responsible for that environment. I know he streams his process from time to time, working with the Quixel tools, but it seems that Twitch can’t find the video when trying to look at an older broadcast. You can see if it works for you.

You should be able to find a breakdown for one of his other environments, the Abandoned Apartment, should be a PDF on his website. Even though that breakdown is for CryEngine, similar principles should apply.

http://www.artbywiktor.com/

Tim_Hobson · June 30, 2014, 1:19pm

Hi abomb, glad you moved from lurking to asking some questions!

There are a lot of different ways to do things in game engines with your modeling assets in general. As others pointed out above, there certainly is a lot of “cheating” going on to get a specific look. It’s not always practical to need something in a game to behave or be replicated exactly how it is in life. A good example of this is God-rays for directional lights. Those are a prime example of cheating! It is common to use a static mesh with a material for the beam rather than having that being created from the directional light in a scene.

I suppose by piece of paper you mean a plane. This is also common practice depending on the artist and their workflow. A lot of that would depend on what is needed for your level design and use for the assets. It is possible that you could model and not use just a single plane as was done. You could start by using a box, detail the single side you need, and then delete any faces that will never be seen in the game. It’s up to you as the modeler to decide what you’re best workflow is to achieve the results you are wanting. Often times when I’m building assets I’ll start with a single polygon and build off that adding detail and such.

Ie. if I wanted to model a a ship from Star Trek like this Romulan Bird of Prey.

I would start with the blueprints depending on availability and how accurate it would need to be. I would line these up and separate the separate views. This video will give you the setup for doing so.

With this approach I start off using a single plane that I manipulate and position to resemble the basic shape of the ship. Sometimes I’ll use splines to get nice curves that I want and then cap that into a single polygon that I have better control over. The next step I would then extrude the faces from a side view to get the look I want.

It’s a process that can be used with single planes to get more detailed objects. Ultimately everything comes back to what you feel most comfortable with in your workflow to get the results you wou

Good places to start with Modeling tutorials: (Not all/any of these are Rhino specific but the concepts can/should be able to be carried over to any modeling program)

http://www.3dtotal.com/index_tutorial.php
http://www.digitaltutors.com/subject/3d-modeling-tutorials
http://www.free3dtutorials.com/

Lightmaps:

The second UV channel is a completely used for baking a shadow map within UE4 when lights are built. This channel provides you with a way to get the best shadows possible for your model. Technically, if you first UV has no overlapping UVs you could use that as your Lightmap channel. I would not recommend this for the simple reason that unless you built that UV with your lightmap in mind it may not come out the best.

This series of tutorials from WoLD not only covers how to make lightmaps but their importance and why they need to be setup in particular ways.
World of Level Design: Lightmapping tutorials

Overlapping UVs are commonly used with the diffuse texture to get the most out of UV space and have a good resolution for your texture. Using overlapping UVs for your lightmap will most definitely cause you problems though. The overlapping UVs will bake shadow information on one polygon and where those polygons overlap on the lightmap UV will carry over the shadow information as well.

Here is a video for the basic workflow that was used with Quixel’s Scifi Hallway to demo their software.

Texturing with DDO is made relatively easy because they are using texture masks (Coloring objects a specific color that their software recognizes as specific materials) to achieve their look.

Take a look through this text wall of information and if you have any questions feel free to ask!

Tim

abomb · June 30, 2014, 3:32pm

WOOOW! Such quality responses! You guys are all so awesome! I half expected the classic “USE GOOGLE” response. I felt my initial question was specific enough to warrant posting about it though. The others I probably could have found… anyway hopefully others will benefit from this thread as well!

By cheated I definitely didn’t mean this in a bad way. I think it was really clever actually. As someone who is/was on the “other side” of video games from player perspective I didn’t really know designers did that. I have always been a curious person so once I got into 3d modeling for jewelry I became very interested in how things are modeled in general. Looking for all these tutorials I even can apply some of the knowledge to better quality jewelry too so that’s pretty sweet.
Thank you josh for the compliment, I love that ring. I still haven’t made myself one sadly.

Those scar models are great! Looks really nice. So on your version Josh, those little extrusions or whatnot on the side near the clip eject button were all part of the overall lower receiver mesh? I am trying to picture doing that with T-Splines, which is basically the closest I can get to polygon modeling within Rhino, but not sure how that would work. In this case I would probably make those pieces separately and then join them together.

SonKim I hope you don’t mind that I downloaded your model you linked in that other forum. I was looking at it in my program, it actually is the same file format I use which was cool. Really great attention to detail in there. I even see that your curves are still hidden so I think I confirmed the way you made it. See isn’t nurbs great? I know with experience a polygonal modeler could probably keep up with a nurbs modeler but I am not there yet. I want to be able to do both. Do you care if people use the file in anything? I can’t wait for that handplane support it looks very useful.

I have played around with the export settings since this posting in Rhino a bit. I am pretty confident I can still use this program for a lot of the stuff I want to do. I am used to the workflow and shortcut keys so it wouldn’t inhibit my progress as much. The biggest hurdle now is figuring the right export settings which look like this if anyone knows…So I can make it more friendly for a different app to handle making a low poly asset and all this UV talk. So the LOW POLY version is the one you want to unwrap? or both… (Are there any reliable & affordable automatic UV solutions? with nDo and dDo i feel like that should be possible seeing how awesome those programs are). I never had to deal with UVs with my jewelry so this is all new, i only heard of it in zbrush a little when I was looking at tutorials for that. I will read up on all your suggestions! thank you.

I hope blender can handle these things well as I will be researching that next. I paid way too much money for the plugin I use for rhino to make jewelry, that is the reason I bought rhino. If I would have known I wanted to eventually do 3d design for games or CG I would have maybe bought maya or 3ds max instead but now how do I pick one if I have never used either? I have seen the question of which one to get before but everyone has their own opinion. I guess I could do the 30 day trials of each to find out.

Im not sure how many different programs I can honestly learn at once so I would really rather skip them for now. I know they are important in this industry, I would actually like a job doing this eventually so I will probably pull the trigger at some point. I have so much to learn of course and I am super super excited to start making some great assets. The NDO video you posted SonKim is amazing to watch, it just blows me away that is even possible without touching a modeling program.

Denny thanks so much for that link that is absolutely perfect. What better way to learn the question I asked then to WATCH him make it!! So happy you found that.

Tim thank you for the tips! I am semi experienced in that style modeling but typically it is all for 3d printing. Yes I meant plane :P. I noticed those are great for making trees or stuff like that with materials applied where it is transparent and looks like a leaf or something. I will look at all these links and see what I can come up with and post on these forums. I think my biggest problem so far is dealing with UV unwrapping, and getting the models I can make into a usable format for the rest of the processes. All this help should fix that.

I am SUPER excited to make really great things. This engine is so impressive to me. Lots to learn! Keep an eye out for my posts I think I will be able to make some really great stuff with all this help. Thank you for all the great responses.

Tim_Hobson · June 30, 2014, 5:39pm

You would definitely want to Unwrap the Low-Poly version. There is no need to unwrap the High-poly version. Since the Low-poly is the version you will be using for textures, lightmaps, and baking your Normal map (if there is one) you want this to be your primary object to unwrap and make game-ready.

There isn’t a really “automatic” way of doing UVs that will get you good results. In 3Ds max there is Flat mapping which will just break everything apart and throw it within the UV space. This isn’t ideal at all. There is the likely hood that two polygons that are attached will end up on different parts of the UV. Breaking your UVs up manually and marking seams for where the model should broken apart is probably best to solution. It’s not a fast process and is one that should be given a proper amount of time to get just right.

Quixel’s NDo and DDo do not handle UV unwraps. They are simply plugins for Photoshop and must be used with Photoshop. They are for Normal map creation and texture creation.

This is a common dilemma that most users face. Blender is completely free and is capable of doing a lot. To me it can be cumbersome to figure out since I’ve always had 3Ds Max. I’m not sure how Rhino is with it’s modeling but you may run into this as well if it’s similar in any way to Maya or Max. If you were going to try Maya I would suggest the 2015 version as they have completely overhauled a lot of it’s core modeling features and coding. Their unwrap has been greatly improved as well. But as you suggested. Give them a try and figure out what works best for your needs.

When you run into issues with UV unwraps feel free to ask. A lot of my expertise is with 3D modeling for games so I can definitely help out in that respect! There are lot of users who are coming from ArchViz background and other areas that do not require or have a need for UV maps and they are immediately running into a roadblock. Game engines heavily rely on these for real-time efficiency and it’s definitely an art form in its own right.

Don’t worry about having to learn a lot of new programs at once. There are still a lot of things I’m picking up after years of working in some of these programs.

Glad to have on the forums and out from lurking in the shadows!

Tim

SonKim · June 30, 2014, 11:07pm

@abomb, Yup it’s my file it should still have the curves intact. I put a lot of time and energy into that SCAR model but I am okay with people using it for commercial purpose just give me credit for it somewhere/somehow. To answer some of your other question. You could UV unwrap the high res version and texture that, then UV unwrap the low res version,Texture the high res then you can then bake all the textures from the high holy to the low poly. Though most people do not use this method because it’s generally time consuming. Most people just don’t unwrap the UV of the high poly version, they only use it to bake normal maps. You’re better off texturing the low poly version in something like DDO/Substance Painter/Insert whatever painting program you like here. It’s always about getting great quality work for the least amount of time. T-Splines are great I had used them in Fusion360 when it was free.

Which software should you use? If your long term goal is to get a job in the game industry definitely learn Maya/Max(check which studio use which software). If anyone is reading this you can get free license of Autodesk product if you are a student. Usually with many software you’ll still need many scripts to speed up the modeling process.

Enjoy the journey.

I did a quick texturing with Quixel Suite(DDO) a weeks ago(was just testing it and really love it!):

http://lookpic.com/O/i2/1879/3ocNT1VB.jpeg

SimpolJosh · July 1, 2014, 5:44am

Yeah that weird little part is part of the mesh. It was pretty challenging for me to try and make it as accurate as I could. Lots of trial and error for me lol. But its pretty much just breaking it down to its simple shapes and planning out how many vertices will be needed for everything to connect properly. For the purposes of a game asset pipeline, it would not be necessary to model it as one mesh as there are baking tricks to give the illusion that it is smoothly integrated even though its modeled separately.