08 January 2021

Realistic Moss Tutorial using Megascans – Daljit Singh

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Introduction

My name is Daljit Singh, from Leicester, UK. I’m a Game Artist with over 12 years of experience in the Game Industry.

During this time I’ve learned the importance of developing environments optimally and always pushed the technical aspects to the edges when doing so. With this in mind I’ve decided to tackle 3d moss – something I hope will feature in the next-generation consoles. Technology is proving anything’s possible with the solutions Unreal provides.

First, you need to decide whether this is something you actually need. Quixel has the Fuzz shaders and maps to generate some nice blends. Something you might see in Ghost of Tsushima etc.

However – if you want 3D Moss like Death Stranding, then follow this tutorial!

Software Requirements

⦁ 3dsmax
⦁ ITOO Forest Pack (Max Plugin)
⦁ Unreal 4
⦁ Quixel Bridge
⦁ Substance Painter

Workflow

daljit-singh-moss-tutorial-part1

In summary, I take a Quixel Bridge asset into 3dsmax > scatter moss cards > dress the asset > export lods into UE4.

Make an Atlas Texture

Find a nice moss that will occupy a lot of space on the card. The more stringy the texture the less it’ll read further away

FOL_MossAtlas_BaseColour

This is a big collection of plants (probably don’t need as much but it’s a personal project.) The main point is to have as many plants on 1 atlas sheet for memory purposes.
After that place the pivots on the moss cards and line them up next to 0,0,0.

foliage_cards

Moss Placement

This can only be done procedurally so you’d need software that lets you distribute 3d cards over a mesh using a black/white texture. I’ve not had time to investigate other methods like Houdini etc but ITOO Forest Pack is quick and within the 3d package.
I’d advise watching the video below to get a better idea of how to use ITOO Forest Pack in this demo Quixel has done for us.

https://youtu.be/iBiod9cQBPQ?t=448

The video demo’s making moss for renders however all we need is a set of moss cards as I stated earlier.
What we want to do is get our cards onto the 3d asset then collapse it all to be an editable mesh.

Play around with the transforms of Forest Pack and you should get a decent result like below.

moss_placement

This is 15k tri of moss cards atm. Some cards won’t hit the normal and face the other way – that’s fine. Just camera select the moss you need and Invert selection and delete.

Don’t be alarmed as what I tend to have is LOD0 around 15k tri of moss then the next 5-8k etc and so on.

Dressing up

After the moss is made you want to begin dressing up the 3d Asset with plants you’ve made from the rest of the atlas texture. Keep them nice and cheap. I’d say 1k for the LOD0 is enough foliage to sit on the asset. This is the final touch to help sell the look – so you have the creative freedom here. Probably the only step that isn’t automated. Enjoy yourself!

dressingup

Optimization

Below is the LOD3. This only has the 3d asset and the plants you created. This is also 50% of the plants triangles found on LOD0.

You will never see the moss at this distance so a good idea to keep it low as possible.

Unreal 4 has plenty of LOD solutions like HLOD’s World compositions etc. I’d suggest if your going to have a lot of different assets you pack them into Atlas sheets similar to what we’ve done with the plants.

optimization

Painting in Moss

Some 3d assets didn’t have enough moss or a decent fuzz map from it’s scan. So I decided to paint it in using Substance Painter. Another solution is probably Quixel Mixer as it lets you paint onto 3d objects now so have a go if possible?

All I did here was load the LOD0 with it’s albedo roughness and normal. Then made another layer and painted ontop of the green moss with a stronger Nordic Moss found in the Quixel library.

paintmoss
paintmask

This mask was then copied over to a new Fuzz layer and basically exported out a new set of textures.

Below: Albedo, Normal, Roughness & Fuzz map.

albedonormalroughness
examplefuzzmap

Then I repeated the steps of loading it into max, placing my moss, dressing up asset. Creating LOD1,2,3.

endresult

Above is the Quixel mesh on the left and the end result after my steps on the right.

Final thoughts

I’m impressed with the final look and I’m taking this approach from now on to other assets in my scene.
I understand it’s looks expensive but technology is providing us with a lot of solutions to these technical limitations. Hopefully in the future this might be the standard our games push to deliver.

Many thanks again to GamesArtist.co.uk for letting me write up this tutorial and feature it on this site.
If you’d like to know more about my work visit my Website or my Artstation page.
Contact: [email protected]