Good looking grass viewed from above?

bitinn

Here is an interesting question I hope polycounters can shed some light on:

- How do you make grass field and grass props that looks good when viewed from 45~90 deg?

I find solutions that work for <45 deg, especially billboard grass, looks very unnatural from a higher angle, even if you orient them towards the camera.

- Have you seen some interesting implementation of grass field for overhead camera in games?

I would love to see some examples that isn't just textures with exaggerated normals.

sprunghunt

I don't know if this is what you're looking for but Horizon Zero Dawn had code in their grass shader that would bend the grass when the player approached it. This would mean you would get a more perpendicular viewing angle when looking downwards onto the grass.

https://twvideo01.ubm-us.net/o1/vault/gdc2018/presentations/gilbert_sanders_between_tech_and.pdf

bitinn

sprunghunt said:

I don't know if this is what you're looking for but Horizon Zero Dawn had code in their grass shader that would bend the grass when the player approached it. This would mean you would get a more perpendicular viewing angle when looking downwards onto the grass.

https://twvideo01.ubm-us.net/o1/vault/gdc2018/presentations/gilbert_sanders_between_tech_and.pdf

nice, this is roughly what i had in mind; I was just wondering if there were other developments on grass rendering beyond this.

Note: nintendo also like this trick, in older zelda games and also the recent link's awakening remake, grasses are tilted to give a nicer view.

bitinn

To clarify, my problem with the tilting technique is it can only do so much when given limited vegetation.

If you are fixed camera and all grass are stylized then it's relatively easy (see Zelda above)

If you are first person and vegetation are varied, then the Horizon Zero Dawn approach would work.

But if you are a game like Total War, then I don't think a simple tilt can make this go away:

rollin

The problem with total war is the length of the billboards, isn't it? 

I guess this comes down to a LOD system. Like every grass strand like BOTW for close ups and a reduced system for grass further away.

About the topic: Grass looks good from above if you mimic the curliness of real grass which requires some geometry. But as there is only one particular spot really straight below the camera this can be used for driving some LOD values. 

Shrike

first step would be having the ground color matching the grass plane color, and you can have smaller grass at the edge of the grass patch, and yes these are too long on total war

Alex_J

Try making your grass into clumps like this:

You can use a lot more grass than you probably think, too.

Another thing that will look cool is give enough geo + wind shader to bend the top of tall grass almost horizontal.