Material testing and car rendering

Hey guys,

in this thread I will share the progress of a litte side project I am doing atm :wink:

First of all, please excuse me if I will fail to provide constant updates. We have a lot of stuff going on at work right now and since I also want to play Lego with my son, there will definitely be hard times in working on this :smiley:

But yeah…its still very exciting to work on this, since its the first time I have UE4 at home (I am used to it from work, however…you know…you dont always have time at work to go crazy in the way you want^^)

This project actually started when I saw an awesome screenshot of a Bugatti concept car from some guy (called jmv design) on deviantart (so the design credits of the car go to him^^). I liked it so much that I wanted to model it and render it in realtime.
The goal is to achieve a look as real as possible (like what I can do with the tech and modify it atleast as far as I can without much coding knowledge). So yeah…getting UE4 actually is a blast for this kind of project! :smiley:

And whats also very cool is, there are a lot of obstacles to overcome (like no good translucency right now, no multilayered brdf with second spec ability…think of multicoated carpaint, no real area lights, etc^^) and that makes it even more interesting to find nice workarounds :smiley:

I have modeled most of the basics of the car hp right now and for the wheels I have a textured lowpoly. I am still using the hp with a veeeery bad unwrap in the engine since I am far away from having the model finished and baked (****…I never thought how time consuming it is to model a car just with a couple of screens and no blueprints xD)…so I guess I will have my slowest progress there xD

The rest of the scene is a material test where I worked on cool concrete tiles and a floor material, and I also worked on a good way to do lightsouces, and, what better way is there than to try nice bubble lights^^
I am also working on a blockout for the scene righ now but I wont show it until its at least something worth looking at :wink:

Sooo…enough writing for now, here are some screens!

This is the lightest I have been working on. I didnt really do much on the post…so lensflare looks crappy and yeah…not much tweaking there yet^^ However I think doing lights like this (even in other situations with bulbs and tubes) could be a nice thing.

Now just a couple of screens of my test room with the car, some carpaint testmats and a couple of lights to see how the reflections behave with different carpaints and the shapes.

Hope you like it and please…feedback is very much appreciated! :slight_smile:


Hey…just a couple of additional screen :smiley: Tried the carpaint in the standart level and I think it looks pretty cool already^^ Just added a skylight to the scene and tweaked the fog a bit…so nothing fancy in here. Still need to get my hands on the source code to tweak the cubemap rez to get better reflections^^

That car looks sick man! Too cool.

Really nice. How many polygons is it?

The rubber material for the tyres needs a bit higher roughness value, but i guess you’ll fix that when the whole car is finished anyway. :slight_smile: I’ll keep an eye on this one!

I’d imagine quite a pretty fair sized poly count on that beast.

Haha…thanks guys! Well…the polycount right now (and totally unoptimized) is at 1,1 mil xD. I modelled mostly with edgeweights instead of supporting edges, which makes it easier to get the shapes without errors but also increases the count quite a bit^^

Yeah man, the roughness on the wheel totally slipped through the net since I was so drawn into getting the paint right. Will probably fix this in the evening :wink:


1.1 million is a bunch but still looks very nice.

1.1 million would have been alright if it included interiors as well, considering how high poly Forza 5 cars are. You can still remove some edge loops if you want to make it a drivable car in the future anyway so it’s all good.

Yeah…but man, this is the full turbosmooth model and far from game ready :smiley: I will not use this in game anyway^^ in the end I guess I will be between 200 and 500k with interior. Btw…the forza cars are only that high in the garage :wink: The goal is to go for a med spec. Old school cars used very low rez models with normal maps and today its common to use no nrm maps at all but go pretty high in polycount. I will go for something in between. I will give it the geo that it needs but still bake it to improve the shading. Lets see how it turns out in the end :wink:

Small update on the roughness of the tire :wink:

Cheers! :slight_smile:

Nice updates to the wheel. That is very nice and realistic.

Very nice. :slight_smile:

I’d like to see the car in different HDR environments to get some color variation on reflections.

Cool Progress.
I would definitely look at some reference of real life or high quality rendered vehicles and shoot for those.
Here is an example that shows a good quality bar to shoot for:

Hey guys,

thanks a lot! Jeremy man, I am loving your ocean shader thread and how you do this project for the community! Thanks for the feedback, I will try to push as much as I can towards exactly what you described :slight_smile:

Regarding the paint shader…
Sadly, I was not yet able to download the source code (aw man, I just come home and start with this stuff and then its late and I remember, **** …didnt you want to download something :D)
so I couldnt adjust the max allowed HDR import size from 512 to 2048. That should actually do quiet a lot to the reflections and how they behave over different roughness levels.

That will work nicely together with another change I made to the cubemapcommon.usf that basically does this (and btw, If you go almost zero with roughness, Unreal does not really choose the lowest Mipmap):

its says that if the roughness is at or below 0.04…always use the original cubemap quality with no mips applied. This and the other change should finally allow me to go for the desired quality (and of course some mat tweaking is involved as well :D)

But yeah…you asked for screens in different HDR environments…here you go^^:

Cheers! :slight_smile:

Now the paint is talking. :slight_smile:

Definitely an improvement
Keep going! A few more iterations and who knows, it could rival rendered images :cool:

Hehehe…thanks a lot guys! :slight_smile:

@Jeremy…yeah lets see how far I can push it^^ The goal definitely is to rival rendered images :cool:

Hey guys,

sorry for the long time without any updates, been pretty busy lately. So here you go, these are the latest changes on the carpaint shader (model hasnt been updated yet :frowning: ) Will post some shots of the mat later as well :slight_smile:

I just added some minor things like fresnel based AO effects and (finally! :D) a normalmap for the paint and some other tweaks to the roughness and metallness behavior.

Hope you like it and feedback is very much appreciated!

Cheers :slight_smile:

Nice work, though I can see some texture stretching along some of the edges near the wheel and the back of the door.

Hey guys,

@SE_JonF yeah, I am sorry for that, its still the unfinished highpoly with no nice UVs that I am working with. I should definitely update this soon :smiley:

Here are some shots of the material:

Let me know what you think! :slight_smile: