[RELEASED] DirectX 11 Grass Shader

DirectX 11 Grass Shader

An affordable way of getting great grass to your project.

If you need the 5.0 version of the shader, you can still download it here.

High performance:
Scalable from low to high end, by generating blades of grass directly on the GPU!

Easy to use:
With a detailed text and video documentation and easy to use controls great results are a matter of minutes.

CPU Fallback:
Systems that cannot use DirectX 11 can still use the optimized CPU Fallback system.

Dynamic reaction:
Reacts dynamically to characters, vehicles, or any other game event.

Artistic control:
Use a variety of included tools to paint grass where you want it or easily create texture atlases.

Highly customizable:
From underwater scenes to alien landscapes. Useable for every art style.

With features from years of support and development:

• Supports Unity terrain and custom meshes
• Texture atlases
• Various lighting modes
• CPU fallback
• Moving platforms
• Advanced interaction system
• Grass painter
• Wind zones
• Texture atlas creation tools
• Detailed text documentation
• Video tutorials

Now on the Asset Store:
https://assetstore.unity.com/packages/slug/36335

Website:
http://stixgames.com/

Documentation:
http://stixgames.com/grassshader/documentation

Discord:
https://discord.gg/jvBFhQA

Supported third party assets:

• Curved World
• Most assets should work without explicit support. Ask here when you are in doubt.

Supported third party assets:

Frequently Asked Questions:
Can the shader be used with Unity terrain?
Yes, the package includes a preprocessor which can optimize Unity terrain for use with the shader.

Can the shader be used with other meshes?
Yes, it works perfectly with custom meshes. To use all features it will have to be UV unwrapped.

Is it possible to remove grass?
Yes, you can also use a grass painter tool to change it directly in the editor.

If you have any questions, feel free to ask!

Example Screenshots:

 

Yeeah, finally. Good job. It was me you sent a link to on reddit (@ddutchie). Will buy with next round of purchases. Thanks.

 

Thanks for the early interest! If you should have any problems or questions, just contact me!

 

Does it work with Oculus? (I guess it should)

 

A few people reported that it worked with VR, including Oculus, but I had one comment that the right eye doesn't render correctly on Oculus. I'll try to fix that bug, but that might be a bit tricky, as I don't have one myself at the moment. (I'll get mine as soon as the consumer versions are out!)

 

Any chance you can add terrain support for specific texture layers? Would make this asset 11/10

In the video comments, you told you did the videos using the terrain, can you explain the process to get it working with a terrain?

 

I tried the texture layer support, but only partly got it to work, maybe I'll try it again later. The problem is that that requires some serious changes to the shader, to be similar to Unitys terrain shaders. Even after that there are still the terrain LOD problems remaining, so the best way is probably to just create the terrain in an external program.

Anyway, here's short guide how to get it to work:

1. Create a terrain object (obviously)
2. Create a Grass material (with the grass shader) and a floor material (with the standard shader or something similar)
3. Duplicate the terrain, so that both are exactly overlapping.
4. Apply the materials to the terrains, this can be done here:

I hope that helped! If you have any other questions, wishes or suggestions, feel free!

 

Just bought and tested but disapointed : there is no more than the simple grass, none of the screenshot's grass is included...

 

Issue with the wind if you move the object (exemple : the plane is moving as a plateforme)

 

Could it be that you didn't see the Grass type / Texture count tabs at the top of the material settings? I didn't include any example materials because I thought it was obvious. I'm sorry about that. I'll definitely include some of these in the next patch, as well as some example scenes. (I only didn't do that from the beginning because some of the textures weren't mine and I didn't have any time to look into their licenses)

Yes, you are right. Using the grass on moving platforms isn't possible because of the nature of how the wind is calculated in the shader. In short, the wind is calculated completely new every frame, it has no idea how strong it was the frame before. For the calculation it uses the position and time since the start of the program, so if you change the position, the shader doesn't know any more how to continue the wind calculations.

I try to add a object space mode, so you can create moving platforms, and include it in the next patch, but that means that the wind will rotate and move with the platform. (I'll try to include as many things in the patch as possible, because the submission process takes quite a bit of time, but it shouldn't take too long)

 

This asset is absolutely beautiful. I've added it to two projects and it's absolutely transformed one of them. Here's a quick video of it it in action

Beautiful asset!

I've found the asset extremely easy to use, reproducing the grass in the videos should be really easy to do. That said, it'd be nice if they were included as additional examples.

 

Watching this. Would love to see a bit better integration with Unity Terrain (as horrid as it may currently be) since we use Terrain Composer to generate our terrains.

 

This looks exactly like my grass. Is this by chance Grid's DX11 solution? Always curious to check out how other people do things so I'll pick it up for that alone.

 

No, I've created it from scratch! I've seen a few youtube videos using similar techniques to mine, but they seemed more like tech demos or small tests.

Also if you want to check out the code, you shouldn't have any problems with that! The full code is included, without any obfuscation or stuff like that. It's split up in a few .cginc files, so start with the Grass.shader if you are a bit disoriented at the beginning.

Edit: I just found the paper to Grids implementation. That's quite interesting! I'll definitely look into it. Could have been helpful a few months ago, but maybe I can still get something out of it.

 

I'm thinking the same, actually, with regards to yours - I implemented Grid's solution but I'm certain I can pull some stuff from yours to benefit. I hadn't actually thought of just applying a material onto the terrain. That would save some cycles, though also somewhat harder to easily control the density. I would presume yours is faster because it does not involve separate rendering, and definitely easier to apply with shadows, because it's right inside the pipeline (I use a command buffer).

Definitely a resemblance - I just run more, but thinner, blades.
https://www.dropbox.com/s/aaun3n2l6ig6bp9/Screenshot_2015-07-01_03-28-53_1.png?dl=0
https://www.dropbox.com/s/83q8y8oku1tdee0/Screenshot_2015-07-01_03-28-47_0.png?dl=0
https://www.dropbox.com/s/girb1aa0bqk1tq0/Screenshot_2015-08-13_03-47-14_15.png?dl=0

Here's a contrasting image with just your code - no lighting, obv, but simple grass, limited LOD -
https://www.dropbox.com/s/i7u8l8rbyaefkuz/Screenshot 2015-08-17 17.10.34.png?dl=0

Love it!

I like my look, but I'm glancing through your code and will take some lessons from it as soon as I get the time to implement it. I won't say anything about the techniques you use directly, but I'm sure it'll improve my performance to skip the render because Unity won't allow me to go straight from a render => append buffer, so I have to do render => MRT for two textures (position + normals) => compute shader => append buffer.

 

Yeah, I'm giving away a bit of flexibility so I can use tessellation. Believe me, getting the smoothing of tessellation levels working was really annoying, but now it's done I think it's working really well.

Still, with a bit of playing around, you should be able to get something very similar to you scene with my shader. Just decrease the width of the grass, like I did here: http://gfycat.com/GrotesqueAromaticBeauceron

By the way, especially your third screenshot looks really nice! I love the atmosphere.

Please go ahead and use as much as you can, but please keep it to your own projects. I'm all for sharing, but the shader is already rather inexpensive as it is, so I wouldn't want parts of it to be given away for free. The whole thing was quite a lot of work after all!

 

Of course! That's what I meant. Exactly why I am not mentioning how you put everything together here. Well aware of how challenging some of these things can be, and how much work it can take... This'll integrate fairly easily into my project (which is commercial), preserve the same look, and probably double the rendering performance of the grass. For $20? I'm happy with that. Code is well written, too.

 

I'm happy to hear that! I've been trying to keep the code as readable as possible for situations like yours.

 

Any web player of this in action?

 

Not yet, but I'll add it in the next few days, after cleaning up the example scenes. For now you can use the trailer or this small (a bit outdated) collection to get a feeling for the shader: http://www.gfycat.com/nonakesh/dx11_grass_shader

 

Looks good. I'm aiming for PS4 which by large only needs a tweak or two (if any) to compute shaders. I'm wondering if it's possible to vary the tint of grass based on a map or such and if there's lod possibilities?

Also we do not use the slow abomination that is Unity terrain - am I right in assuming it will work on meshes too? I'd like to use a different weight map every so often - is this possible as well ?

Thanks!

 

Color, height, density and weight maps are all supported. The shader actually works better with meshes than with Unity terrain. It also has it's own LOD system, where grass density is automatically reduced based on distance to the camera.

Unfortunately this doesn't use a computer shader. It uses tessellation and a geometry shader. Until Unity supports these features for OpenGL there's not much to do about it, if you don't want to essentially reprogramming large parts of it.

 

Oh I see thanks.... hmmm! That changes a few things - how well does it respond to lights? We need our grass to be lit by Unity's lights and hopefully that still works? Deferred of course.

 

It works with all types of light. It can also cast and receive shadows, although shadow casting increases the performance cost quite a bit. Right now there's a small visual bug when using it with the deferred renderer, but I already fixed that and will submit the patch with some other changes (like example scenes) in the next few days.

 

Well I am picking it up, why not? $20 gave me no choice.

 

cool

 

Hiii @Nonakesh ^^

Really impressive Shader you got there *-*

My questions are:
Can I use it on any Mesh...!?!
Or
Can I use it only on Terrain...!?!
Can I paint it or is it based on texture...!?!

greetz ^^

 

Yes!

No, using a mesh works actually better! You can use the terrain, but it has a few disadvantages.

It's based on textures... but you can paint the texture!

I should definitely create a FAQ section for the shader.
Anyway, please go ahead and ask if you have any other questions!

 

I think a tutorial video on how it works might be beneficial. I am still sort of unsure as to what it entails to be able to paint grass using this shader on a mesh/terrain.

 

That's one of the limitations with the terrain. It's not possible to paint it with the terrain system. I'm sorry I didn't make that clearer, I'll definitely include it into the FAQ section I'll be writing. It might actually be included in a future patch, but I'm not sure how big the changes I'd have to make to the shader are.

If you want to use weight maps, or grass height maps for that matter, export the terrain as a obj file, or create a new mesh in a 3d modelling program and create a weight texture for that, just like you would create a texture for any other object. For example, in Blender there's a texture paint mode that could be useful for this.

 

I was going to say apply it as a second material, but I suspect for Unity terrain you'll need to set up a custom terrain shader. It would have to basically just add the grass as additional passes, but referencing the main splat maps, with a toggle for which splat channels allow grass on them. The only caveat being you'd probably need to make a script for settings, rather than a material editor, since the unity terrain would not allow it. Otherwise, it would probably be a somewhat simple addition since you wouldn't need to modify the base terrain shader or passes (but it would break compatibility with other custom terrain shaders).

Unity's terrain is kinda confusing, I figured I'd double check before suggesting anything, but boy. I simply set it up so I can select which UV channels/vertex color channels I want to be valid, so it can be added in additional passes for grass and use the same vertex data. Even then, if you could just simply apply a second material to the terrain, and have a helper script set that material to reference the same splat maps, it'd be able to just sample those as weights without all the confusion of a whole new shader set.

 

Yeah, the main reason why I didn't add terrain splat map support from the beginning is because Unity's terrain is just seriously confusing. Actually I had the support already working at one point, but it suddenly stopped working after some changes and I gave it up again.

It's also a bit problematic, because you'll essentially need two different terrains. If you use one terrain object/prefab you'll only be able to have one splat map for both the ground textures and the grass, but as soon as you split the terrain into two objects, it will be seriously annoying to keep both of them in sync.

I'll look into it after the first patch with the more important changes, but seriously, I hope they'll overhaul the whole terrain system in the future. It seems like the most inflexible thing in Unity right now. It seems more like a relic from the engines beginnings than anything else...

 

My thoughts would be to not split it, and have one splat for both ground & grass, letting the person designing choose which channels to apply grass to, since they would most likely want a texture underneath. Then if they just wanted one way to paint grass, it'd be tying it in with one specific texture and painting that.

Still annoying, but that would be the simplest way to support it without confusing anyone (at least, I would hope...). Then instructions are simply "pick a texture to put grass on! Or pick multiples! Paint on the terrain like normal!". Since I imagine the users most likely using the terrain are the ones who would not want something requiring lots of setup complications. 2 cents from someone who doesn't use the terrain!

 

I simply don't advocate any support for Unity terrain, it would be better to place the burden of responsibility on end users with a healthy how-to guide (or simple conversion tool), enabling you to better focus on the core product ie optimisations. Not least because Unity's throwing existing terrain out in the not too distant future.

As for painting, there's a few interesting ways to paint splat maps within unity, ie https://www.assetstore.unity3d.com/en/#!/content/41837 which could be adjusted for use.

 

This is pretty cool, I'm looking forward to updates. However, I'm having issues with the grass "flickering" when using textures. Additionally, the LOD popping is very noticeable to the point that it actually draws attention. Other than that, I'm pretty happy and it's definitely a promising asset.

Speaking of which, you might want to link to this thread from your asset store page, because it probably answers many questions potential users want answered before buying this. Additionally, you might want to consider making the manual public so people can have an idea about the work flow before they buy it.

Was there an official statement on that? That would be so great. With terrain being in the "Research" category of the road map I was thinking it'd be a long long while until something was going to happen about it.

 

Not too distant could still be a year. I can't say because I'm not making it. I have heard it will be a fair bit different though. In other news, I'm pretty sure using meshes turns out to be faster in most cases if people handle their own lods.

 

Btw: a suggestion for densities - a good approach to LOD is from the grid system (I think it's in there?) - you can gradually expand the blades widths as they go further out while placing less of them. I did that in my first two screens - the far one has better performance, even (and thanks for the feedback on the image; 100% procedural & voxels, it's been a fun project so far and turning out well).

Edit: This is for simple grass, at least. Not sure it'd matter for the other types.
Edit2: You do both of the things I mentioned. So, just a mention of expanding the blades as you go further out. If they stay relatively the same in terms of screen-space size it's hard to notice.

 

Thank you for your answer, here i made a list of enhancements you can make :


1. If there is any limitation to your grass system, you should notice it in bold. If a knew it couln't move i would wait to buy it
2. You made a good visual communication, a good website etc ... it gives the crave to buy : But you should work a little bit more on the "dev-communication" part :

2.1. Make a video tutoriel on how it's working : how the grass is working, how you can make/add your own textures, how the interaction with other objects works
2.2. Make exemples scene. It's very important to have an exemple with at least one texture, to see how it works
2.3. If the screenshots are not included in the package you must say it in bold. For my part i expeted the flowers to be inside .
​

Now :

1. Can you assure me you will make an "object space mode" ?
2. Is it possible to disable the wind ? It would solve the problem, espacialy if you don't need the wind
3. Can you send me the link/package to the flower exemple from your screenshots ?
4. If you made a local mode before to send it to unity it would be nice to send it to me, i will of course send you my paid invoice so you can confirm i bought your asset.

Thank you for your time

 

The flickering is already fixed and will be patched soon. That is, if you are talking about the flickering that only occurs when being in deferred rendering mode.
The LOD should not pop at all, except you are using Unity terrain. I'll definitely put this limitation on the store page.
Edit: Except you disabled the smoothing at the top of the shader options.

I think these are both good ideas.

If the licenses allow it, they will be included with the example scene!

I actually have them from here, so it should work: http://www.cgtextures.com/
The example scenes won't be the same as the trailer, because except for the stones and the grass, everything is from assets, some paid.

I'll look into it today. I'm fairly sure it will work.

For now, you could disable by setting the wind strength or speed to 0, which essentially turns it off. I think I'll add an actual turn off button though, that could reduce the performance cost a bit.

That should be possible! Just send it to me via PM, preferably with a screenshot of your work! I'm always curious to see the grass in action!

 

Great to hear that's been solved! Right, so you need to enable the disabling of the smoothing. That works, thanks.

 

Thinking about it.. it kind of IS confusing. Don't worry, I changed that right now. I also added another smoothing mode that changes the width instead of the height, which looks quite a lot better. I have no idea why I didn't come up with it until now!

 

I just implemented the object space mode, so yes I can assure you that it will be included in the next patch!

 

Hello,

I was having an issue getting the circular displacement working. I believe I followed all the steps listed in the manual. Adding the colliders and putting the grass on a specific layer. Is there anything else specific that I need to do to get this working? I just built a demo scene with the default grass prefab with the standard unity third person character controller as the displacement object. I have tried using both the dynamic texture adder and a manual texture but the grass doesn't seem to be responding to it.

Thanks in advance!

 

Sorry for the problems, I'll create some example scenes and submit them tomorrow (it's almost 10PM in my time zone right now), that should hopefully clear up some problems.

As the submission may take a while, I'll just try to help you here.

Just as a short clarification:

• The grass needs a collider (and a grass layer for optimization)
• The grass needs a displacement texture, the higher the resolution the finer the details, but the performance cost will increase as well. The texture has to be editable, which the TextureAdder script does automatically.
• The player, or displacer, doesn't necessarily need a collider, just the script. The script will send a ray, as soon as that hits the grass, it will change the displacement texture.

If you still don't have any changes when all that applies, you may want to look at the settings of the displacer. You could increase the radius or strength and decrease the falloff, just as a test.
You could also put a normal map into the displacement texture slot, just to see that the displacement is actually working. If it STILL doesn't work in that case, it might be a bug and I'll look into it in more detail!

 

I've modified it, but I've largely moved to this system completely - here's some pics -

https://www.dropbox.com/s/at5nx99c16n6kn4/Screenshot_2015-08-19_05-10-19_4.png?dl=0
https://www.dropbox.com/s/tekvz4pvb1c8223/Screenshot_2015-08-19_05-10-33_5.png?dl=0
https://www.dropbox.com/s/185cju2c54kjabt/Screenshot_2015-08-19_05-11-07_7.png?dl=0

The main modifications I've done are taking HSV color values into the fragment, and then applying some random modifiers for blending hues to whatever I want, I've tweaked the LOD and density settings to scale it better in the distance, and I scale up the width based on distance to the camera which preserves the 'thickness' of the grass. It's now running about 4ms faster than my old solution - plus I get the possible shadowing, displacement, etc, though I haven't linked them up yet. It's also running in deferred, not forward.

I'll stop spamming your thread now - but it's been a fun exercise to set this up!

 

Please do spam and share optimisations haha

 

While creating the example scene, I just remembered another important condition for the displacer to work: The grass mesh must have a UV map or the displacement can't work!

 

So are these screenshots with my shader now? If so, you've managed to recreate your old visuals perfectly!
Also as @hippocoder said, please do continue to spam the thread!

 

I just submitted a patch with the following changes. It should take about 5 business days until Unity accepts it.

1.1.0:
- Fixes a bug that caused flickering artifacts in deferred rendering mode.
- Adds a unlit rendering mode
- Adds a additional and improves grass LOD smoothing mode
- Adds a example scene with example materials and the displacer in use
- Adds a object space mode for moving platforms or similar (I forget this one in the package... oh well, I guess @Timothee35 who requested it, will see it here anyways!)
- Cleans up the grass material editor

 

The oculus rift is broken in one eye, this dissapears when you turn off cast and recieve shadows. Seems like shadows are broken...
Otherwise, amazing! Is this similar to GPU fx, low draw calls?

Thanks