[RELEASED] DirectX 11 Grass Shader

I know you're busy, but I'm literally releasing the game tomorrow. Please help !!!

I was getting the same two errors as above on compile. It turns out, it was due to the grass being hidden in a scene when I hit build. I don't know how any of this works, but goddamn this was annoying to figure out.

Unity 2017.1.2p4
Version 1.82

 

Will this asset support Vulkan instead of DirectX in the future?

 

If the cross-compiler of unity gets fixed, this shader should run fine on openGL and maybe even vulkan. However, all Unity shaders are written in HLSL and cross-compiling has proven to be tricky. Here's the issue that prevents at least openGL. https://issuetracker.unity3d.com/issues/shader-does-not-compile-under-glsl-due-to-miscompilation

 

Directional light which is more than 90 degrees away from the grass normal (it's shining from below) causes NaN values, leading to artifacts with TAA. Any chance of having this fixed? Thanks.

 

Hello,
I was wondering if it is possible to render a projector or decal clearly over the actual grass mesh to show things like unit selection/range? I have experiemented with render queue and everything is just drawn either beneath the grass or the grass culls the decal.

To put it another way does the shader render to the depthbuffer? (zwrite on)

 

It turns out one scene with baked shadowmask lighting was causing these errors for me. It was the only scene with baked lighting in my project and it doesn't even have any grass in it.

Is everyone else able to use shadowmask lighting and grass together in their project?

 

Hi,
i'm using this plugin to simulate a dense grass field under the player in a vr game, but i'm having some issues i cannot solve.
It seems the grass have some zfighting problem, and it clip and flicker a lot upon close inspection (around 1 meter range).
I'm on the last stable unity version (Unity 2017.3.1f1) with the last version of the shader.

Someone could help?
Thanks a lot!

 

Same problem here !

 

I am currently optimizing the game I'm working on which is using this grass shader. In the quality settings I plan to allow the user to reduce the amount of grass that is shown by changing the max density on the shader at runtime. I wanted to check if this is a good way to handle a quality option for the grass or if there would be any known issues with changing the max density at runtime.

 

Does this system currently work with deferred rendering?

 

Hi Nonakesh, sorry for not getting to this for a loooong time, been busy. Is it still ok to ask for help with this? In my project I still see the ghosting of the blobdisplacment, burn cutoff value change does not help. I also tried changing the mesh no help..

 

Hi,

Are you aware if this works within Nintendo Switch and if not, would you allow me to test it prior to purchasing?

Thanks

 

Shader error in 'Stix Games/Grass': invalid subscript '_ShadowCoord' at Assets/StixGames/DirectX 11 Grass Shader/GrassFrag.cginc(36) (on d3d11)

Compiling Vertex program with DIRECTIONAL SHADOWS_SHADOWMASK GRASS_CALC_GLOBAL_WIND GRASS_USE_TEXTURE_ATLAS GRASS_WIDTH_SMOOTHING THREE_GRASS_TYPES
Platform defines: UNITY_ENABLE_REFLECTION_BUFFERS UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BOX_PROJECTION UNITY_SPECCUBE_BLENDING UNITY_ENABLE_DETAIL_NORMALMAP SHADER_API_DESKTOP UNITY_LIGHT_PROBE_PROXY_VOLUME

Same error here. Build is VERY erratic. Sometimes it builds, sometimes it fails. I'm puzzled...

 

Do you use baked lighting in your project?

 

Is this in a large project , maybe a shader limit has been reached?

 

THEY FIXED IT !!! YAY
https://issuetracker.unity3d.com/issues/shader-does-not-compile-under-glsl-due-to-miscompilation

It should work from 2018.1 onwards

[UPDATE]
It works, just make sure you're not using metal on Mac

 

Lucky you!

 

@Nonakesh
There seems to be an issue in OpenGL when using Unity 2018.1b13
The grass blades don't catch shadows. Could you look into this?

 

Would it be wise to set mesh as static and have it included in occlusion culling?? I did that and while running around the grass, it's flickering in and out. In other words, the OC is making it appear/disappear... a lot.

 

bump.. ??

I had another issue start happening. After baking lightmaps, the grass is flickering in and out darkto normal color. The plane which has the grass shader is not set to static. Also, the grass is not receiving shadows. This is happening when I move the camera.

 

It has something to do with my lightmaps. I cleared my lighting cache and now the lighting on the grass is working as it should. I'm baking again to see if it happens again.

 

I appears that setting the main directional light to "Mixed" causes the flickering of shadows. If it's set to realtime, this will not happen. But if you bake your lightmaps with the directional light set to mixed, the flickering will occur until you rebake with the directional light set to realtime.

 

Hey there, sorry for being gone for so long. I've had some health problems lately, nothing serious, but enough to stop me from doing basically anything work related.
I'll go through all your problems and will try to help. Also I will start working on a CPU based Fallback system, which should partially solve all compatibility problems that exist with the shader. With the current plan, you'll still need a DirectX 11/Windows system for creating the offline materials (the scripts will use the shader to build a texture atlas), but after that is should even work on mobile.
Of course I will also be reachable via email and private message again. Again sorry for not being reachable lately.

 

I notice your mesh renderer does not cast shadows, if you turn that on does that help resolve the issue?

 

No, I tried that. Thats the mesh that the grass shader is on. It doesn't need to cast shadows

 

Judging from the screenshots it looks like your directional light settings could be the problem. Can you post screenshots of the mesh renderer for the grass material and your light?

 

It was the directional light. Setting the directional light to Mixed or Baked causes this to happen. Setting it to Realtime works.

 

Is the grass set to static? The grass is moving, so baked lights can't work with it. It must not be set to static.

 

It is not set to static. See my image above of the inspector window for the plane.

 

That definitely sounds like a bug, I will look into the problem, but for now you should just avoid using baked lights. I think the shader should work with the real time global illumination baking, just not with the static one.

 

Is there a way to get the grass density consistent when using the shader on a mesh with different sized quads? The density seems to be different depending on the width/length of each quad. The UVs are consistent, but the tessellation doesn't seem to take UVs into account.

 

As I've said before, the density is dependent on quad sizes because of how tessellation works on the GPU, so it's possible to normalize the density between all quads, but only by reducing the density of all smaller quads, you can't increase the density above the max. I'll look into this problem, maybe I can find a solution.

 

Hey, you shader looks good, but I would appreciate if you didn't post it in this thread. I have put a very large amount of work into this shader and while I appreciate open source, I think it's a bit... direct, to post a link to your project in the official post of another project that isn't open source.

That said, here's what I think of your project: The point cloud technique is quite nice because you gain a lot of control, but I believe (and we've had another user in the forum who came to the same conclusion) that it is still missing the raw power of tessellation. That said, being able to do things on the CPU instead of the GPU should make it far easier to implement LOD and other techniques, but it will likely be hard, if not impossible to reach similar density as with my shader.
Good luck with the project, I'd be happy to discuss it further with you in private messages!

 

Why could you not create your own post for this? That is way more appropriate. It's a separate topic isn't it? Anyway looks ok, PM me your new topic and I'll check it out. PS I like Nonakesh's one lots, it's tough to beat IMO.

 

I've tried solving it myself, but haven't had any luck so far. Which is strange, since it seems like it should be a fairly standard use of the tessellation.

 

Last time I tried to fix this problem I noticed that tessellation regulates mesh density without problems as long as the maximum density is not reached. But as soon as very large differences occur it can't handle it any more.

I personally came to the conclusion that the best way of fixing will be a mesh preprocessor, that automatically splits triangles that are too large into smaller ones. The smaller differences will then be handled by the shader. I will look into this problem once I have finished the fallback system.

 

I skimmed through the manual but I would just like to check; Does this only work with the unity terrain tool? Or can I use this as a material on a mesh?

 

This is probably the question that I get asked the most, apparently the FAQ isn't enough.. anyways, yes it does work with meshes, actually it probably works better with meshes than with Unity terrain, because Uniy terrain has it's own LOD system that interferes with the grass (not very noticeable, but still)

If you have any other question, I'm happy to help!

 

Thanks for the fast reply. However in regards to an FAQ, that may have been enough... if it was linked to in the store page

 

... good point. Well, it's in the first post of the forum, but maybe I should really make a own section for it somewhere.

 

Hi,

I've noticed when playing under 4K screen resolution, the grass density is much higher if the base geometry's vertices are dense enough. How can I limit the max screen resolution parameter for the shader? Becuase I spend most of the time trying to adjust the density of different grass materials under 1080p resolution. I would like to see the density keeps the same when screen resolution scales up.

Thanks.

 

I noticed that bug myself, while doing some updates. I have now fixed the density to be the same for all resolutions. The update that will contain this fix is still in progress, but I could post the one line that has to be changed, if you want (I'd do it right now, if I was on my PC).

 

PS after a loong time (of giving up due to other tasks) I re-visited this and discovered that my Ambient Occlusion was causing this effect.. I am currently working on moving the displacement mesh up higher than the camera view to avoid this, might be useful for others to know, if using AO.

 

Would you mind posting the altered line please? I think I'm seeing the same issue.

 

Sure, here you go:

 

Spot on Nonakesh! Thank you very much.

 

Is it just me or when placing the grass the size brush doesnt work. It only works when the size of the brush is half way to the largest size.

 

I just tested it myself and it doesn't seem like it. Maybe your density texture is too small, so one pixel is larger than the brush size? Could you post a short gif of it?

 

Hey @Nonakesh. I've been using your asset and it is great so far. I've encountered one problem though. The displacement system doesn't work on ground that isn't facing 90 degrees.

Example:

I am trying to run around on a cube. The displacement works correctly on the top face of the cube, but not any other face.

Any help would be greatly appreciated!

Thanks.

 

The displacement system work by using a camera that is pointed from the top downwards. In special situations like yours, where you want to run around a spherical planet, or a cube, this won't work. If you really need the displacement you could try creating a custom solution where you create the displacement texture directly and map it to the UV maps of your cube. Or you could rotate the cube instead, so the side with your player is always at the top.