Texturing PBR materials in 3D Coat and exporting to Unreal 4

3D coat generated an ambient occlusion and a curvature map for each object I painted in it - that way it knew how to paint in crevices that are stored in the imported normal map.
It was excellent in this regard as I found out that it can handle memory quite well when compared to Substance Painter. In 3d Coat I was able to get over 40+ layers on 2x2048 maps of 3 paint objects - with all channels + normal map. In substance painter - it just crashed on the second or third layer I made (preview texture set to a miserable 512).Even though my laptop is 7 years old - 3d coat handled this one quite gracefully.

For the skin I used one of the leather pbr shaders that came with 3dc and heavily altered it to make it look more like human skin.
Of course it is really difficult to fake SSS in real time. Unreal engine - which is the target engine for this character does have a SSS shader, but since the character will not get any closeups and not much of the skin is really revealed- I decided to be cheap again and stick with one material for the entire character. Before texturing the body I made an import test of the head/spray mask texture.

I set the texture maps in unreal in a way where the alpha channel of the diffuse is used to store the roughness map pass. I also wanted to use tha alpha channel of the normal map to store the metalic pass, but I found out that Unreal 4.10 does not allow using the alpha channel of a normal map texture if the file is a png. A few forums noted that it will work if I use targa instead - but targa is a huge file size and I thought i wont be saving a lot that way.

Gangsta-mask by blurymind on Sketchfab

I imported my character with the unreal rig applied to it.
Here is the model - you should be able to preview it in your browser:

Hero TPP by blurymind on Sketchfab

For the spray cans in the game I used an rgb map to split it into three areas - cap, sticker and can . The alpha channel of the sticker controls the sticker's mask in this case. That way the programmer on the project - Steve Stavrev can control the color of each instance of the spray and even change it dynamically during run time to create some interesting effect. 

His pose and animation is not my work - it is using one of the unreal project examples. Since my binding pose and the source binding pose are slightly different, the actual animation is a bit screwed up on the target. Unreal 4 supposedly has nice tools to adjust binding poses and when this issue is at hand, but I discovered that as I am writing this (4.10.4) there has been a bug for over an entire year that nobody from epic fixed that stops the users from doing that. I had to blindly set up the bones in blender, but the fingers are still screwed.
The best thing to do here for my portfolio is to actually make the animations myself, but unfortunately the freelance nature of the project dictates that we make do with this.

Some notes on baking Normal maps again

Flipping UV islands is a common way of getting more pixels to cram in detail. What you do is for each symmetrical part of your model, you take the left side and flip it over the right side.

 That doesnt mean that the entire left side should be the same as the right - if you do that your model will of course be a bit bland. So plan in advance which parts you want to have symmetric and which not. You should plan it right from when you start making your high poly model.
In my case, I sculpted the nude in Zbrush completely from scratch, but used marvelous designer to create his outfit:

Making the hoodie was a  gotcha moment.I had to first stitch it in neutral pose over his head and run the simulation to get it to wrap around it naturally, then I puled it down to fall over his jacket during another cloth simulation. He looked good with a hoodie on, but the final design was planned  with a hat on instead.
Marvelous provided some really nice realistic cloth simulation which resulted in a good starting point for wrinkles and detail. Bringing the clothing back to Zbrush - I added detail to it - more wrinkles and a zipper here and there, the shoes and shoe laces. The hat, the hands and the respirator mask are all made in blender - where modelling them made much more sense. For the mask I used modifiers heavily. Wireframe modifier was perfect  for the cage.

Naturally the generated cloth mesh had no symmetry. So then when I started doing retopology in blender - the plan started forming more. For the outfit I will keep the middle part asymmetric, but will reuse the texture space of the sleeves. Same goes for the pants. His face will be completely unwrapped, but I will reuse uv texture space of the neck, the the cap shade and the shoes.


So I did the model accordingly in two stages- first retopo the asymmetric bits, then do the ones that reuse texture space - with a mirror modifier. I had to cut the hi poly model import from zbrush and marvelous designer into body parts and make the planned ones symmetrized for the high poly mesh - where there was no symmetry for the clothing. Thankfully blender has wonderful sculpting and modelling tools that make that part a walk in the park.

 When baking a normal for a target model with flipped islands that overlap their counterparts, you are most probably going to get seams.
If you want to avoid it, but still be able to reuse texture space via flipped uv islands, it is important to do this: Select all islands that overlap other islands, and move them in X + texture.width.


As a side note you need to consider that this UV technique does not work if you need to bake a lightmap on the model - which is usually the case for static background objects.

For the mask normal baking, I arranged the uv islands in a way that it will bake the bars perfectly horizontally and vertically. It is generally a good practice to arrange your islands in a way where you will get less diagonal lines on the bake - try to avoid diagonal straight lines as a whole. Horizontal and Vertical lines have  no anti-aliasing you see - so geometric detail such as this looks much crisper on lower texture sizes. If you look at model rips from old video games - you will see that they utilized this approach quite successfully to get some good looking textures as small as 256 or even less. I was also being cheap again with reusing UV space  with a vertical mirror. Whenever you can, and especially for detailed parts with repeating elements - try to reuse texture space!

In most cases, you will still need to clean up the bake result.
The normal cleanup was done in Krita, as 3D-Coat does not allow cleaning up external normal maps. Their import layer is locked and limited to very few operations.
 It was however quite good at further detailing them during texturing with your PBR materials. Next post will be about that =)

Creating all the 3d graphics for a Kinect game - to teach kids how to cross the road

 A few months ago I just finished working on a game with Tri-soft.  It was created in Unity and was using Kinect for input.  The Goal of the game was to be a part of a larger event that is aiming to teach kids about road safety in a safe environment. The game came out and it even got some media coverage. Seeing as to how kinder-gardens and schools are using it now, I would class it as a successful project. You can watch the media coverage here (more pictures and video)

The deadline for it was tough. I had a month and a half to create ALL the 3d graphics in the game. The entire pipeline - including animations on three kids - one on a bicycle.

When we first started, the game was planned to be photo-realistic. It had no art style guide. So what I did was make one and offer it to the client - before doing any concept art or even modelling.  

I had to make sure that I know that they know what they want and I know what they want! :)
I offered them a short presentation of two styles - a cartoony one and a realistic one. Then left them to decide which one fits the target audience (little kids) more. The choice was obvious.

It was great that they went with the cartoony style, because it was much faster to produce (not requiring any normal maps) and it worked with the limitation of the old computers they have at the schools.
The target device handicap also forced the team to use Unity instead of Unreal engine.

 I couldn't get the game to look as good as I wanted to, due to the deadline. But I am somewhat happy that it is at least out there. Of course, I had to make some changes along the way to meet the client's demands. Also those ground textures were not my job.
For the characters:  After submitting a quick concept art drawing, I didn't get any reply so everything seemed fine. However when I got to the stage where the models of both kids were ready and textured, the client asked me to change the girl's dress completely, give her pigtails, change the boy's hair color and give him a red cap. In these cases, stuff like that always happens, but it is better to have something already made and easy to alter, instead of keep waiting for the client- halting the production. It's best to have something to give to the programmer to play with early on.The changes were in part with the issue of having the game displayed with a digital projector. The colors were getting washed out and it was not easy enough to see on the screen in which direction the kid's head is looking- looking at it from behind. I had to use very bright colors. On why they wanted both kids to be blond - I have no idea :D

I had to use my time wisely. In order to meet the deadline and leave some extra time for unexpected issues and client demands (which of course there were some) - I planned the assets in a way in which I can reuse things. Even at the stage of the concept art, I designed all three kids very similarily - where shapes deform - so as to be able to reuse the geometry of the first one to create the other two. This also allowed me to partially reuse textures (instead of starting from scratch), reuse skin weights, the rig and partially even animations!

The kid on the bicycle was a bit more complicated. Due to the bicycle being partially controlled by player input, I had to create a rig for it in a very specific way. That required a lot of back and forth communication with the main programmer. Thankfully he was a great guy and helped out a lot technically.

Finally the last dynamic object in the game that had to be designed was the car! For the car I wanted something that looks like a toy. The programmer asked me kindly to use more realistic proportions for the car in terms of distance between the tires. This wasn't too big of a problem anyway. Both the car and the bicycle were made in a way that would allow him to control their steering and speed dynamically with code. That part I didnt have to animate at least. For the bicycle I did all the animations, in a way that would still leave him with some control.

After all that concept art and planning, it was time to do the actual models! Even when you look at their screenshot, you can really tell that they have the same base mesh (which probably is not a good thing, but time was not on my side)!

 For the buildings: A big part of the work was done in blender. The excellent modifier and instancing system allowed me to create a big number of assets very quickly and save a lot of time in UV unwrapping. 

 Before modelling anything, I went out with my camera and took reference images of real places and things. The school is based on a school that I used to go to. The kindergarden is the one I grew up in. Even the ugly Eastern European communist style Blocks in the game are based on one that I used to live in.

 Each model of a building was planned in advance - so as to pack textures in the most efficient way and use the smallest amount of geometry possible. In terms of UV unwrapping/texturing, it was important to take note in advance which were the repeating elements in a building and what Islands I can overlap or even flip in order to save uv space - giving each building texture more resolution if the client wants more detail later on.

There were quite a lot of buildings to make. Some of them had more than one different variations- In texture and in number of storeys. On storey variations I simply used the array modifier. There was also quite a lot of mesh instancing used and snapping.  When modelling all the assets, I kept them all in a single blend file that (at least in theory) had the correct units set to export and also had some consistency in art style.

Finally here is a trailer of the first version:

Most of all I am glad that the game was made for a good cause. I hope that none of these kids ever gets run over when crossing the street. Would be nice if they liked playing the game too of course. :)

Speaking of good causes...

I used Krita for texturing. It's vector layers and color adjustment layers made my life very easy. It even has ALOT of amazing features that photoshop does not have and probably wont get anytime soon. Things like brush stabilizing, more than one brush engines, layer instancing, wrap-around view mode (great for tiling texture painting), a vastly superior to the bucket tool  fill algorithm (via gmic), and many more are completely missing in photoshop at the moment. Krita is free and open source - unlike Photoshop it doesnt require monthly subscriptions and is available on Linux too!

They currently have a cool kickstarter campaign to fund development and bring more features. Most of all the campaign is to get krita to run faster than photoshop and to become a dedicated 2d Animation application as well - meaning a complete animation system - unlike the one in photoshop!

You can download it right now and start playing with it. The funding campaign comes with some great goodies- such as an awesome learning dvd course for example.