Models:
Firstly, pretty much everything is extremely low poly, I can only assume it is due to the skill level of contributors as it certainly isn't winning you much in terms of performance. Polys are an outdated measurement for performance and say almost nothing about the in-game performance, vertex count is closer, but even still, modern hardware is at such a point that thousands of vertexes aren't really a problem any more. The vast majority of your performance is not dictated by vertex count, and I seriously doubt, given your game style, that you will ever see the tens of millions of vertexes required to produce any significant performance hit. My conclusion: Do away with low poly entirely, it looks crap and doesn't help the game, start using high poly, well optomised models and you will see what I mean immediate.y However, that doesn't mean there aren't gains to be had from your models:
The biggest performance hit from your models currently is that every single one of them has double sided faces, and many of them also have hidden faces. This is an absolutely no no. Double sided faces means that your game engine is drawing the inside of every single model in the game, effectively doubling the amount of system resources used to draw any given scene. Simply going through and making them single sided will give you a better performance increase than any amount of poly count hoarding. The hidden faces are also a big problem it means you are rendering things that no one will ever see, and that is a needless waste of resources, particularly when you are rendering both sides of those hidden faces.
Textures:
so you have these tiny poly models, and yet you give them gigantic textures? Is this some kind of over compensation? 2048x2048 png 24 for creatures that have a handful of faces and spend most of their lives taking up a tiny fraction of the screen is insane. You could redo all of your textures at 512x512 png 8 and barely even notice a difference.
Here is an image to demonstrate what I am saying, this is the troll texture, displayed at a level of zoom which would correspond to zooming right in on him ingame.
the current Troll texture is on the right, 2048x2048 png 24, filesize 6,500kb
An alternate troll texture on the left, 512x512 png 8 filesize 136kb
That means your current troll texture is 47 times(!) larger than it needs to be. And on top of that it is being drawn twice by the engine, meaning your engine is doing 94 times more work than it needs to every single time it draws a troll.
There is another issue with your creature textures, in that many of them use mirroring in their UV unwrapping, which renders very poorly, and the situation only gets worse once you start using normal maps, since simply mirroring a normal map produces the wrong results, meaning your creatures end up looking blurry and the light bounces off them incorrectly. I'd recomend re-unwrapping and retexturing all textures that use mirroring, otherwise you are shooting yourself in the foot.
Normal/specular maps
These are sorely missing, I understand they are on the todo list, and I would make them a priority, particularly for your walls. If you are going to have low poly models then normal maps are of critical importance to avoid everything looking like boxes.
Environmental Textures
The number one thing missing from your engine at the moment is environmental texture variety, your whole world is made out of less than ten textures, all of which are tiny little tiles. There is simply no way to make that look good.
In this image I replaced the existing dirt and rock textures with higher quality versions,
and then zoomed right in. As you can see that looks better, but it doesn't matter how good I make the textures, because each of those textures is then tiled hundreds of times in every direction. It is simply not possible to have any texture look good under those circumstances. What the engine needs is a way to provide texture variation. The two easiest ways to achieve this are:
slightly altered tiles
this is the easiest way, I just make up a set of dirt textures which are still seamless with each other at the edges but are different in the center.
pros: easy to implement
cons: still looks relatively crap as different texture types still jar.
Automatically Blending tiles.
pros: looks great, is easy to add new textures into and allows for huge variation in theme.
cons: difficult to implement.
Personally I'd be recommending the second option, but either way is better than what you have now.
a final point on environments, your project is meant to be dark, and yet most of your environment textures, and indeed many of your creature textures are lightly coloured. If you want to convey a feeling of darkness, shiny beige floor tiles are not the way to do so.
Folder Arrangement
My last point is that the contents of your folders need to be better arranged. At the moment, with a relatively small amount of media, its not too bad, but as you gain more an more content the situation is just going to get worse and worse. Having all of your environment textures, creature textures, item textures, material settings and effects, all in one folder... that is a recipe for utter chaos. I would highly recommend rearranging your folder hierarchy so things are more logically ordered and divided.
I mean look at this, its a mess:
Final Conclusions
It seems to me that up until this point the art in the OpenDungeons Project has been functioning in a fairly ad hoc way, I would suggest that there needs to be some strategic direction and a unified artistic vision, which can best be achieved by establishing content guidelines and todo/request lists. This appears to me to be a key priority if OpenDungeons is ever to move form being a techdemo into being an actual game.
In regards to content guidelines, I'd suggest having a look at the DungeonHack content creation guidelines as a starting point: http://dungeonhack.sourceforge.net/Art_Workflow_3D
I hope I haven't trod on too many toes, and if I have I hope it doesn't hurt too much because I feel much of this needs to be said. Goodluck and good day.
