Thinking about some RPG..Android version.

[Thomas.]

Vainly trying to figure out why everyone are using normal mapping in tangent space instead of object space. Object space is faster and less memory-intensive. Or what is main differences?

[EgonOlsen]

Object space normal maps can't be reused on different objects and you can't create (...fake) them simply based on a texture. In addition, using them on deforming objects can be an issue.

[EgonOlsen]

This is how the AI sees the world:

[Thomas.]

Every red point is obstacle? I see monastery and houses Do you want these models? They are from my old and probably dead project...

[EgonOlsen]

Yes, they are obstacles. The smaller dots are mostly trees and rocks. I've you've some models to spare, i would be very grateful.

[EgonOlsen]

Hunted by a pack of goblins...

[EgonOlsen]

The NPCs now may have a (very subtle) blob shadow. I wanted to add this for ages, but i hadn't figured out how to do it efficiently on Android. After all, a simple flat shadow plane that moves with the character won't work in this terrain. It has to adopt to the terrain to a degree but i couldn't use a projective texture either. So i had to look for a way to make a plane roughly follow the terrain without impacting performance...and this is it:

[Thomas.]

Nice, did you have any problems with depth buffer accuracy?

[EgonOlsen]

Nothing noticable. The plane is shifted a few units up, which you usually can't see. I tested it on desktop, Adreno and Tegra so far and it works fine on them. I'll try on PowerVR once the damn slow Nexus S has finished all updates that it thinks it has to install (haven't turned it on for some weeks). The Mali device is on holiday together with my wife, so i can't try that ATM...

[raft]

looks nice  how do you make shadow plane fit to terrain? using collisions similar to car sample? ie: 4 collisions for 4 corners of plane?

[EgonOlsen]

... using collisions similar to car sample? ie: 4 collisions for 4 corners of plane?

No, not exactly. That was my first idea but it had the problem that it was much too slow on Android to do it that way. But i already have this height map that i'm using for npc movement anyway and i have a method that returns the current height at any point based on this height map and a strange linear interpolation. I'm using this to take three samples around the enemies position and calculate the normal vector of the plane that these three points span. I'm then using a linear interpolation between this vector and the former one and rotate the shadow plane to match the resulting vector.
So...it's a linear interpolation of a linear interpolation of some height map values...sounds strange but works pretty well.

[IZACIZAC]

Are you streaming in map data, or pre-loading it all? Just curious because I am trying to stream map data and have no idea how to do it efficiently, any pointers would be awesome

[EgonOlsen]

Nope, no streaming. It's loaded as one large lump of geometry. It's not that large, so that's not a problem. I'm not trying to create something in the range of Skyrim here.

[Irony]

Looks definitely better with the shadows. Can you already shoot those bastards? 

[EgonOlsen]

Can you already shoot those bastards? 

Yes, in the latest version, you can shoot them with the bow.