UE5 Procedural Grass Using Bezier Curves (Ghost of Tsushima Technique)

In this video we will create a blade of grass for which the shape can be procedurally defined using a bezier curve. I show the process for a quadratic curve, although the technique works for higher order curves as well.
Part 2: • UE5 Procedural Grass U...

[@givemepen0]

UA-cam front page really feeding me this gem, great explanation

[@TechArtAlex]

Thanks!

[@BooneyTune]

This is actually an advanced technique. Thanks for looking into it and sharing

[@TechArtAlex]

Thanks for watching!

[@UriahGnu]

Good to see ya back in the mix, love your content!

[@TechArtAlex]

Thanks! It was a busy period for me, but I've been wanting to make this one for a long time.

[@UriahGnu]

@@TechArtAlex btw you might be interested in checking out the original Outerra blog where Ghost of Tsushima got the idea, there it is used at a planetary scale.

[@TechArtAlex]

@@UriahGnu Yeah, I have seen it, great stuff.
The LOD system they used for it works a lot like how Unreal ended up solving volume preservation for nanite foliage.

[@muhammetemirbulut6511]

very nice bro good to see back

[@TechArtAlex]

Thanks!

[@lordkelvin1]

All your videos are top notch, keep em coming!

[@TechArtAlex]

Thanks!

[@vyacheslavkuzmak3086]

Update: My fault, missed the subdivision adding for the rectangle itself.
Great tutorial! Never throught mathematics could be so amazing. I have one problem for now, after adding "transform vector" node, width stops working, goes back to simple rectangle. But stil works with Local Space option, checked everything few times for now

[@UnrealArtist]

Thank you so much,

[@TechArtAlex]

Thanks for watching!

[@arvinmoses]

Still looking to dig into this but I agree with people here - your stuff is sooo good. Are you at a studio anywhere?

[@TechArtAlex]

Thanks! No, I'm not at any studio currently. Just doing this stuff independently.

[@arvinmoses]

@@TechArtAlex wow the implementations are very clean. Really probably my favorite source for useful production viable shader tricks

[@arvinmoses]

@@TechArtAlex any thoughts on how to break up the shadow map? I'm testing some painterly rendering techniques and it works well except the shadow maps are still super crisp

[@TechArtAlex]

@@arvinmoses Depending on the stylization you're going for, you can potentially extract the shading/shadows in the postprocess by looking at the difference between the base color and the final scene color. By isolating the difference, we can tell how the scene is shaded.

[@arvinmoses]

@@TechArtAlex ty! I'll try it. Ive used this before to grab the lighting values and map to a ramp, but never tried grabbing cash shadows from it. The other thing Im testing is to maybe grab the stencil pass and create a breakup there. Thank you!!

[@evzircon4152]

My grass cast a square shadow, what to do?

[@TechArtAlex]

The only reason I could see that happening is if you were using raytraced shadows without enabling the feature "use WPO with raytracing".
I strongly suggest you don't use raytraced shadows for the grass, as it will be extremely expensive. I talk about shadows more on a later video.

[@evzircon4152]

@@TechArtAlex Thank you! Just wrong shadows misled me

[@NorwinLabs]

Random queston. So I have made it though episode 7 and When viewed at a low angle, my grass material has a black shading issue on it. I believe it is too low and is in the ground when viewing in the material editor. How can I fix that? Is it a model issue?

[@TechArtAlex]

Is the artifact only in the material viewer, or does it also appear on the grass in level?

[@NorwinLabs]

@@TechArtAlex both. It tanks my fps and if I turn off world position offset, or switch it to transparent it goes away and viewing it anywhere, it has it. I suspect it is detecting it is underground. When I spawn it, I have to elevate it with pcg because it spawns clipped into the ground. Maybe it's contact shadows?

[@TechArtAlex]

@@NorwinLabs of it is clipped below the ground then your mesh pivot or UVs must be different than how I've set them up in the example. This could be adjusted but I set it up the way I did to minimize shader math.
It could also be the setting "affects distance field lighting" in the mesh spawner. This setting often causes black artifacts.

[@NorwinLabs]

@@TechArtAlex It was affects distance field lighting. I was using the wrong pcg graph. Thanks!

[@GMTechArt]

Alternative - ua-cam.com/video/gfQNjC69PCM/v-deo.html

[@TechArtAlex]

A great approach for sure

[@swoorp]

literally was looking for this haha, thank you

[@TechArtAlex]

Lucky day! Thanks for watching.