Making grass look good in-game?

grimsonfart · Mar 2014

Hello

I have a quick question to the foliage masters out there, how do you get the grass to look so good in-game.

I know of a few techniques, both modeling the grassblades in 3Ds or taking pictures of straws, but which one is actually the best? (can't really figure this out myself as i don't have a good camera).

I have heard of people using some kind of opacity maps, but i can't figure out how that works, seems to be very little information of it. I have seen people use that on bushes and canopys for trees, gives it that outer lighting and inner darkness.

Any other techniques that might be usefull? Il gladly try out anything you guys trow at me!

Wesley · Mar 2014

Posted a couple of days ago. Might be of help.

http://www.crydev.net/viewtopic.php?f=315&t=100319&utm_content=buffereb577&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

grimsonfart · Mar 2014

I have seen this post numerous times. Modeling the grass is not really a problem for me, so this post does not really answer my main question.

Thanks anyways :poly124:

Neox · Mar 2014

there is just no "best" for every case, both can work great if done right.

Mark Dygert · Mar 2014

"how do you get the grass to look so good in-game?"

That depends on the game, the resources available for grass and what look you are trying to pull off. Like Steffan pointed out there isn't one way to do it. It's a balancing act between a lot of other factors. You are asking a broad generalized question but want specific answers but don't specify a lot of the necessary details.

What engine? Unity, UDK, Crytek, homebrew?
What game? Are blades of grass, tree sized to little players, are players giants or somewhere in between?
If giants, do they ever lay down in the grass?
If tinny do they ever fly above it?
Is the grass small tufts in a courtyard or sprawling grassy hills that go on for miles?
Does it need to react to dynamic forces like wind, vehicles and players?
What kind of light step ups are available in the game? Are they static or do they change?
How does the engine handle opacity sorting and opacity blending?
Does it cause a lag bomb if you see through 2 or 3 transparent objects at the same time?
How will any of that effect your layout?
How will any of that affect the overall game design?
How will any of that affect the way you build the models and layout the textures?

grimsonfart · Mar 2014

Mark Dygert

Engine: CryEngine.

General FPS, regularly sized grass like you would see in most games.

It should move in the wind, for example using CryEngine automerge feature.

Engine does handle opacity blending.....

Lots of things to answer haha.

THats what i have right know. Not very happy with it...

Wesley · Mar 2014

You realise that tutorial has opacity grass at the end right? It's not just about modelling them and sticking the models inside of CE...

grimsonfart · Mar 2014

Wesley, that is just for growing grass, but that said it might be usefull for other things too, i kind of overlooked it

Wesley · Mar 2014

Well at the very end it touches on 'growing' grass. But the whole thing is great, about modelling the grass to create your own style that suits your environment, and then baking out those alpha maps for your low-poly game-ready grass.

Depending on how tall your grass is you could then look at micromovements in CE.

http://docs.cryengine.com/display/SDKDOC3/Bending+Setup

leleuxart · Mar 2014

Since you're using CRYENGINE, play around with the vegetation tools for random size. Are you using the Vegetation shader too? There's a Backface Lighting(something like that) slider, you can use that to fake variation. Random rotation + random size + adjusted backface lighting can give you some nice variation. Add other plants too.

Also, although this won't show that well in screenshots, get the grass moving through the vegetation shader and setting Bending to 1 when you paint them out. You could also use the AutoMerge feature, but from my experience, it works better with individual cards.

Making grass look good in-game?

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