in our project we have massive problems with our foilage (all bought UE4 Assets).
One problem is the rendering. Very often if you stand very close to the foilage (grass, plants and trees) the texture is displayed very blurry and looks incredible ugly. So far I havn’t figured out a way to fix it. I changed the lod setting and tried a few other changes, but without any effect.
As I said, it is the same issue with all our foilage, no matter if it is a tree or a plant
The other big issue is the performance. After placing some grass on the landscape as a test the framerate dropped from 60 FPS down to 17.06 FPS…the test area was quite small, I placed grass cluster and it rendered around 4000 planes.
This is all generated from , some of these examples you just buy and download. I agree completely with what you’re saying though, 14,000 tris for a piece of grass??!
the cattail cluster from the screen from the static mesh editor is not what is massplaced in the level, it will be only placed near rivers and lakes, or somewhere else were it is wet.
The massplaced grass is the grass rough and the whole cluster has 720 triangles
Still too much -> with another technique you could place 120 ordinary grass meshes instead of just one. It depends, how your lod’s look like? (tri count)
Go to segments and scale it down. Probably the issue. That or makes planes in Maya or such a program like . IMO is not the best for grass if you want any real performance at all.
@ : Yes, once I have a suscription for the Modeler I could reduce the polycount and make tons of variations and bushes from my bought trees and plants.
What I don’t understand is why is selling IDV assets that are not really production ready, if a small field of test grass is dropping the framerate by 40 FPS
It would be great to have a official topic here (post release) were user could ask IDV about certain problems with products and UE4.
I will probably try it on their forums, but I remember they pointed every question related to and UE4 to Epic Forums. I think once the grass performance issue will be under controll, I’ll face the next huge performance knockout when I start to build the large forests in the north.
As for the asset issues, particularly the Cattail model, we probably put too much stock in our naming convention. You might notice that we label the resolutions we ship as Hero, Desktop, and Mobile. That’s probably misleading you guys – sorry about that.
To us internally, these labels pretty much refer to the rough triangle counts and not necessarily that they’ll work well in dense populations for the named platform.
Hero: ~10,000 - 15,000
Desktop: ~5,000 - 8,000
Mobile: < 1,000
For strictly grass models, we do offer planar versions, just not this one yet. I talked to the artist who designed the Cattail and she said her intent was for it not to be used as a general grass model that might be used to populate a whole field since Cattails normally grow at water’s edge. It was meant for sparse populating. That said, she’ll be updating it to include lower resolution varieties this week. For those who already have it, you’ll be able to download the update when it’s available.
We’ll have an engineer come and address the issues in this thread very soon.
the performance issue was caused by the Rough Grass Desktop Cluster, the cattail wasn’t involved there. I mainly bought it to be only placed near rivers and lakes (mentioned somewhere above).
I plan to subscribe to the Modeler as soon as I have more time to concentrate on foilage itself, which should be in 1 or 2 month.
At the moment placing foilage is some sort of test and blockout until all foilage resources (Bushes, Containerplants) are done.
There is nothing preventing you from making extremely optimized grass in .
My old grass was made in 3DS and worked great, but recenly made the same thing in using a plane prepared in 3ds to give them the same functions as my trees and smoother LOD transitions and the performance is just as great, if not better.
We have updated the cattail model to include an even lower resolution model that should be good for populating grass, Mobile_2. Anyone who has bought it can download again from their store dashboard.
As for general optimization of grass, you’ll need to edit the densities and culling settings the same as you would for non- grass. Set a good far cull distance and utilize the PerInstanceFadeAmount node in the material to have a smooth transition there. Smaller foliage clusters will enable the grass to be culled closer to the frustum, but it’s a tradeoff against draw calls. Adjusting the instance settings also improves occlusion of the clusters. The documentation on foliage explains all the settings:
For -specific optimizations, grass should probably be just one LOD and no billboard (since it fades out in the distance anyway). If using LOD, adjust the LOD distances on the meshes if you are using them for foliage; the defaults right now are probably closer to what they should be for individual actor trees. You can get away with setting wind to the lowest setting (fastest) in most cases. Grass models are usually so short most of the fancy wind effects won’t be noticeable. Grass close to where the user will walk can be desktop models, but you’ll want to use the mobile versions for further away or highly dense grass.
Cluster models may or may not be helpful for grass. UE4 foliage is already using mesh instancing, so a cluster will probably just be harder to place than the single model since it is wider and will not conform to the terrain as well as more single models. You can probably adjust the foliage instance settings to achieve a similar look.
One final nuclear option for somewhat-further-away grass (that can actually work for trees, too) is to only import the billboard or lock the mesh to that LOD. Paint that model further away. This is really good for trees on a hillside or something where the user never gets close. Billboard meshes will still sway with global wind (fastest) if it is enabled in the Modeler.
Hope this helps
EDIT: Just for clarification, “cluster” refers both to the chunks of instanced meshes the UE4 foliage renders, and to the naming convention on some models that include a handful of similar plants/trees in one file.
Your grass has 14.000 tris (when you use the one on the picture above ^^) -> that’s too much. Normal gras just consits out of some planes (e.g 6 tris)
