TERRAIN TIPS 

HeightMaps

[X] Recommend not using a map larger than 1024x1024
[X] Can use 24 bit but it needs to be 'grayscale' like with shades 
of gray an 8bit 256 colors.
[X] The more dark the shade of gray the lower it will plot 
your terrain. (Ditches, creeks, valleys.)

TERRAIN TEXTURE MAPS

[X] You can use 8 or 24 bit images.
(recommend using 8 bit textures for best performance)

[X] SURFACE TEXTURE TILING:
You can split up larger terrain textures into 2, 16 or 64 pieces 
and select each section on the terrain, and simply select the texture 
from the texture list. 

Use the below guide:
Fullsize    Texture      Texlog2  Tile Qty Size of each  Notes
1024x1024 0 1 1024x1024 Very low Q.
2048x2048 1 4 1024x1024 Low Q
2048x2048 2 16 512x512 Good
4096x4096 2 16 1024x1024 Better
4096x4096 3 64 512x512 Easier to use previous - for same Quality
8192x8192 3 64 1024x1024  -=BEST!=- Currently 
**Only works for 8 Bit 256 color textures only! 

**This limitation is being fixed as I write this.

If you make a terrain that is not Square, you have to make the
 FULL SIZE texture reflect the proportions of the terrain.
Then You will have to resize it after you create it to a "square" size. This is to avoid 'stretching' appearance on the terrain texture 
after you apply it. 
Or else you would be apply say a 1024x1204 texture on a 1204x2048 terrain. and it will have to stretch to fit the terrain. And this will be noticeable!  One way around this is to avoid sharp cliff like sections like shown. A less steeper slope is
desired

 

Optimization:

Visibility on terrain is based on players "frustum' or 'what's ahead'.
in the players cone of sight.  So your frame-rate will be based on what is in this view. This includes all that is not seen as well that would otherwise bee in the player view ahead if the terrain was indeed flat. so hiding objects behind a hill won't really affect the performance. Keep this in mind as you look form the top view as to try not to place random detail in the 'line of sight' where to many things are in the players 'frustum' at one time. (when possible)

[X] Quads:
 
You have to balance this on Optimization
 (affect on frame-rate and speed of real-time rendering) 

-versus-

Appearance. adding more Quads will decrease frame-rate speeds
But will improved quality in the shape of the landscape.

Textures:
Use 8 bit texture/256 colors when you can. Simply reduce the color in a good paint/image editor like Photoshop or Paint shop pro.
Also, consider how much detail you need on your map. First/third person game will require better resolutions for example.

Always use the terrain TerrainObject for larger open ground surfaces. It better manages optimization than a larger brush.
Even for a flat surface.

How the outdoor Terrain is (currently) optimized
What is rendered is what is in the players frustum
or 'field of view'. Keep this in mind as you build your scene.
Having too many objects like Actors and world geometry in the a given frustum at the same time will greatly drag down the Frames-pre-second. Spread out the detail so as to not be able to encompass to much into one view. 
Scroll down below, as coming new features will almost eliminate this worry entirely!

3-3-05
Terrain VIS.

Prior to this feature added by "Krouer"
of the Jet3D development team. The terrain was rendered, 
even if you looked from inside a sealed cube.

Shown below in wireframe (line) mode, you can see
 in blue, the terrain wireframe shows through inside the sealed cube.
Note how you don't see anything but the terrain, no actors,
the skybox that wraps the terrain. Only the terrain mesh shows, 
so all the while indoors it is as thought you are still on the terrain. Bad frame-rates, poor performance!  This is still going on with
Other game engines as I speak. And this is why in these games you don't see a player go into an indoor area without a "loading" of a different map level.

 

So many game engines, have to keep indoor and outdoor areas in separate levels. So if you enter a larger cave or indoor area of a building,  they would set another level to load as they enter.  

This is NOT the case with Jet3D now!
A new feature added to Jet3D actually enables you to place larger indoor buildings on your large terrain! It works just like VIS, in that when you enter the building past the set VIS portal, suddenly the all of the outdoor geometry is Not rendered. After all why should it be?
This means great frame rates, and you don't have to load another level when exiting the terrain as with my example.

Another cool benefit to Terrain VIS:

EMBEDDED AREAS

First look at the two images below:
('Excuse the 'test' maps, as they  are a bit of an eye sore.)

(Above) A large hollowed room, deeply embedded in the and it 
even goes below the terrain object.

(above) Shown Inside the CUBE. Note the terrain is not seen in the cube.
No bumps, mounds poking through the floor here. : )

What you are seeing is not really the cube cutting a hole in top the terrain, but what is happening is the terrain is not rendered inside the cube due to 
this new feature.

(Below) So if you cut a doorway into the cube the terrain is suddenly rendered and shown inside. Since you allow the VIS Carefully planned, you can make say a tomb that is flooded with sand, go around a corner and go deep into the tomb lower than the terrain. Caves, secret under ground bases are now possible on the terrain without loading a second game level to enter or using a teleported.
As you can place your VIS portal at some point to not render the Terrain.

Far clip plane
New feature as of v2.1..
A set radius inside JDesigner3D from the camera properties,
all beyond that radius will not render as though it has been cut-out or 'clipped'. The trick here is to conceal the clipping in outdoor areas with carefully mapped hills, obstructions, etc. Fog will help here as well. If you make it thick you can block the visibility so that you can't see through the fog to see the far clip plane 'cut-off' points.

FOLIAGE and TREES
v2.1.1 Can't yet be added without heavy drag to scene statistics. These are feature set for next release that will aid in the use of detail in your terrain scene:

JetMesh
JetMeshes will use a DX9 function called 'ID3DXMesh'. This  will be used with the Dx9 driver for this new Object called 'JetMesh', which is much like Unreal Static Meshes.  With a JetMesh, you can have several instances of the same Mesh without the duplicate meshes taxing the performance of the rendering. (FPS) In other words you can have 100's of trees, and yet performance will behave as though there is only one tree in the scene. This also means we can soon have foliage all over the terrain, without the drag on performance. As with the tree example, you could create 5 grass types. (sheet brushes) And cover the entire terrain with 100's of copies of each one of these, yet, it would be as though only the original five sheet brushes are there in the scene.

Actor LOD
Actor CLOD- Actor CLOD will consist of 16 or more levels of detail.
If you choose to detail your scene with actor models this will help optimize you scene statistics and performance.

Other soon to come features that will help scene performance

Hardware T&L

D3D fog. 
Used well in games like Dungeon Siege.
The fog can be set to black to simulate darkness. Basically D3D fog blocks the rendering of what is not visible beyond the fog.

Lastly Terrain LOD.
As we see 100fps on the tested terrain (see screenshots), so Terrain LOD is the last on the list since so many of these features mentioned above will truly make Jet3D terrain a powerful feature.

TERRAIN for extraordinary uses.
You can lay another terrain into a ceilings or an area to make a cave looking area. same can be done to walls. What you will find is that terrain object can intersect with itself, brushes, actors

More to be added soon...

- Ken Deel

To report "errors" and to post comments e-mail us at kendeel[at]mail.com

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