I rarely make requests for new features, but here is one which I think would be very useful for many people: a more flexible LOD system.

While the current LOD system is fast and simple to use, it lacks some important features.

1) ability to use different types of entities as LODs, specifically the ability to define a sprite or model as part of one LOD chain. This would be useful for doing things like large numbers of plants or trees, where you can turn your tree model into a sprite at a certain distance. (of course this can be done in script, but it not so easy to manage all these sprites and such, would be much better if you could just define your own LOD chain)

2) Furthermore, if you can define your LOD chain, you could also have the option to set individual properties for each LOD level, such as materials. Also there could be some way to transition between the LODs smoothly. For instance if you are going from a model to a sprite, it would be nice to have the sprite LOD appear first, before making the model LOD disappear. This too can be done in script, but not if you want to use static entities.

i'd like to hear comments on this idea..

This would be really nice and a LOD for Shaders also (->other tread)

Yes I agree and I would like to add the idea to have some kind of material LOD with chunked terrain as well. Distant blocks of the terrain could have another material and another texture just to save shader performance and FPS.

You can see this in Oblivion that visible distant terrain chunks have a very small texture without multitexturing.

Different LOD entity types are normally not necessary: A sprite is just a model consisting of 2 polygons.

A LOD transition by blending two models does not sound good either - LOD is normally used for rendering faster, but this would be slower than not using LOD at all.

However, other LOD improvements do make sense. Built-in LOD meshes for models are planned - you then don't need different models for LOD levels - and we'll then also provide a solution for different LOD materials.

At the moment, you can just use different LOD models with different built-in materials.

OMG, a miracle Automatic LOD-Meshes would be very nice

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Different LOD entity types are normally not necessary: A sprite is just a model consisting of 2 polygons.

A LOD transition by blending two models does not sound good either - LOD is normally used for rendering faster, but this would be slower than not using LOD at all.

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Yes but a sprite faces the camera automatically, a model does not. This way you wouldnt need to have a script that make the model fact the camera. Also, replaceing models with sprites is just faster, because sprites tend to be faster than models.

The LOD transition DOES make sense in some circumstances, such as when you are going from a model to a sprite. Specifically if you are using billboards for distant trees, making the sprite LOD appear first make the transition look better. This is how Speedtree (oblivion trees) work.

Please consider what I'm saying, my ideas are based on observations of how otehr engines solve certain problems, and my own experiences.

My LOD system (explained in another thread) is much more flexible than even described here. LOD stages can be defined at any distance and can be unique to each entity (even scaling the distance with a simple mathematical trick). You don't have to have only 4 entities, you can have any number from 2 to infinity (or however many you feel like making). It can also be used to allow for different degrees of accuracy for collision by making all but one of the LOD entities passable and the distance is checked on only one entity as all others are at the same distance. This kind of flexibility means a lot.

@Matt: Yes, you are right with the sprite orientation. However I believe that you can already switch from a model to a sprite in a LOD chain. I'm not 100% sure - try it. Otherwise we'll implement a flag that turns models towards the camera.

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Specifically if you are using billboards for distant trees, making the sprite LOD appear first make the transition look better. This is how Speedtree (oblivion trees) work.

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Matt's right, it would be a good option to have the sprite appear first for transitional purposes. I know from my own tree system, putting 1 big leaf on a stump before scattering the smaller leaves to different trees looked better than scattering first then putting the big leaf.

Also wanted to say thanks for the new LOD feature in the beta for techniques. Makes it easier.

chunked level geometry with lod would be kind of interesting. kind of like octree level geometry but optionally lod stages can be stored for each octree cell. the lod cells could have multiple textures baked into a single one and also simpler geometry for example.

i read a "shadow of the colossus" making of and there they used such a system for their vast landscapes (that game runs on a ps2 though). i think the gta games use something like this too...