I would say its not that UE4 is hard. Its a good system with good guides. However, it is not a lone-wolf system. It suites minimum size teams but not the best for a single person. 3DGS is harder to learn, but supports a single developer style creation.

@Malice: haha, I see no rats around it is possible to make a 3DGS refugees page on the forum e.g. at General Discussion ...and maybe a 3DGS to UE4 page would be useful...

As I recall the animated movie, the Piper lead the villages children away when the village leaders didn't the bill.
A fitting metaphor for engine that doesn't maintain its services and see it's users leaving in masses.

to be honest I know pied piper from here https://www.youtube.com/watch?v=h2LG7JXK5mQ

I realized if you want to test real performance it is better to test run the project in standalone mode, and fps can be written out by a console command stat_fps.
It runs fine in 1366x768, even with 400 animated characters onscreen (with LOD, the same I use in 3DGS) and some thousand instanced static mesh trees, having billboard LOD (shader can be get from LandscapeMountains demo). A desert scene could perform even better

@sivan, which engine has higher fps with your setup (army, trees etc.), gamestudio or unreal4? Unreal4 I take it?

Thanks for sharing your experiences with unreal4 by the way.

it is a bit difficult to compare them, but approximately:
- with lower quality stuff I use in MapBuilder (small lod and clipping distances, simple sky cube, simple fog, terrain lod with 2 times smaller vertex resolution, bone animation shader similarly with 400 similar characters, simple shaders especially for lods etc.) and with about max 1000 tree and building entities per level, 3dgs is faster. even if a few thousands of grass models are placed with short clipping (having no collision!).
- but over a certain scene size and detail level, I mean e.g. thousands of trees, 3dgs performance falls rapidly down to unplayable level (I've never used the model merging offered by the TUST library), while UE4 is more stable and optimized for such an environment, even beside an advanced sky system, better shadows, complex vegetation and terrain shaders with physically based rendering, longer view distance of terrain (I try to scale lod distances and clipping approx similarly). probably if I optimize the environment shaders I got from UE4 samples it would perform a bit better. and UE4 renders faster higher poly models thanks to its effective occlusion culling, and other many optimization tricks I don't know.
...and soon I will test it with a nice water, and with many moving and colliding characters on the navmesh (what I will probably replace with my own pathfinder).

basically, working with UE4 goes a bit faster after you get familiar with ue4 editor and its sub-editors:
- for your free subscription you get cool textures, models, materials, animations, and game play codes (or blueprints) you can use freely.
- I find blueprint visual scripting difficult to overview over a certain detail, but cool and fast for simple things.
- the programming side is much more complex! but there are UE4 helper solutions for everything (e.g. dynamic arrays) to make memory handling safer, which requires significant time to get familiar with, especially to build C++ and blueprint classes onto each other smoothly. it is very difficult comparing to lite-c, and requires more preliminary learning and planning!

A some month ago, I downloaded Unreal engine and I started to make the same level that I already did in A8. I very carefully make complete level to keep everything the same like in my 3DGS level - position, size, settings, number of models,... everything. And fuck!!! A8 is faster?! Can someone explain to me HOW THIS IS POSSIBLE? All this time I was convinced A8 is an poor and outdated engine. I expected all will explode with Unreal Engine, but this has not happened
To make things worse for me, this Blueprint thing seems quite confusing and is not useful as I thought, and writing code with C++ is not funny - it's very complicated and hard for me, and Lite-C here have a big advantage.
I must admit that I not enjoy working with this Engine, maybe is too hard for my level of knowledge -> I do not know, but I belive that soon it will be removed

This performance gap can be explained very easily: A8 IS very, VERY outdated - that means there are only so many ways you can torture your hardware with it. If you build a scene that runs well in A8, it probably is not very complex by modern standards.
Now, you port this not very complex scene to UE4, an industrial-grade, state of the art engine, and suddenly it performs WORSE. How is this possible?
Well, the short answer is, UE4 is very very potent, offers A LOT of features, very modern technology, and these features simply come with a performance cost, even if you do not make full use of them. And if your PC is a bit older, it will have problems. UE4 is not designed to run on old machines out of the box, you can make it perform well on older hardware but you'll have to enforce some optimisations that it may not apply per default.

However, a very complex scene, using a lot of effects and features that UE4 offers you, and that runs well on a modern machine, will run very slow, if at all, when ported to A8, EVEN on the modern machine.

Long story short, UE4 has higher baseline hardware requirements than A8, yes. If your PC doesn't meet them, you will have poor performance no matter how complex your scene, and you may get better performance in A8 as long as your scene is not too complex.
To make use of UE4s potential you will have to upgrade your machine.

@sivan @the_clown, interesting but makes sense. So basically GS3d performance is good enough unless you go for heavy first/third person shooters or high-budget games like graphics (which is harder to get right anyway as an indie unless you buy models or work with a team).