How can need for speed car racing game's terrain get created? Did they use heights map? or using 3D models to create the terrain? http://www.gamespot.com/pages/image_viewer/frame_lead.php?pid=920469&img=13 any 3D model on the web i can download to create "need for speed" type of terrain? Thanks

You mean the road? Yeah, that is just a model. You may be able to buy a road "set" , but i think it would be best to get a modeler to do the job. Using prefab models for something like a road may be kind of tough to just throw into your game.

O i see, how about the buildings on the side? so it's also 3D models i guess?

I think the sky is using a "SkyBox" right?

so in all racing game, all the terrain is using 3D models instead of a "height map"?

is that 3D models is better than height maps as height maps is only good for mountains kind of landscape?

Quote: Original post by stmarsp5910
O i see, how about the buildings on the side? so it's also 3D models i guess?

I think the sky is using a "SkyBox" right?

so in all racing game, all the terrain is using 3D models instead of a "height map"?

is that 3D models is better than height maps as height maps is only good for mountains kind of landscape?

I'll assume you're new to game development. In which case lets break things down a bit:
1.)Games don't always have a set way of doing things, it depends on their situation and approach.
2.)Games go for what is more optimal (fast).

Knowing this and looking at the screen shot i can see that:
1.)The road is made of a model.
2.)The buildings are models too, but since they're not casting any type of stencil shadow it would be safe to assume they're shells. That is, the buildings are only modeled to show their fronts, facing the player, while everything behind it is deleted. However, because of rule 1 stated above, we can see that this approach is used because they didn't have any type of tri/face culling to remove the backfaces, so their approach was most optimal. However, such a thing does not need to be done in a modern engine with such backface culling.
3.)Certain items in the scene may be a sprite. That is, a single faced model with a transparent texture, one which could be animated or not. This is used because you're driving at fast speeds, it would be unlikely the player would notice if the model was completely modeled or just made intoa sprite, as such the best solution is a sprite for certain small objects.
4.)The sky and other far away (very far away) scenery in the sky is probably using a skybox.

Now that we have broken down the basics of the scene, hopefully you'll see that their approach to everything was what was optimal with their engine and their platform.
So:
"so in all racing game, all the terrain is using 3D models instead of a "height map"?"
You can now see that, depending on your engine, your platform, and your approach, you can use either a heightmap road or a modeled road.

"is that 3D models is better than height maps as height maps is only good for mountains kind of landscape?"
Depending on what kind of heightmap system you have going, models may be a better solution for certain things like cliffs. However there are heightmap systems out there that support things like cliffs, and mountains and other such terrain. However, if your heightmap system does not support this then it is quite common to use a mixture of models and heightmap generated terrain. It just depends what your situation is.
In your situation i'm thinking a mixture of models and heightmap terrain would be best, but i don't know what engine you're using so its hard for me to say.

edited: Removed error, thanks soconne.

[Edited by - Jarrod1937 on November 28, 2007 7:26:16 PM]

Quote: Original post by Jarrod1937
2.)The buildings are models too, but since they're not casting any type of stencil shadow it would be safe to assume they're shells.

I don't believe there's anything stopping a shell from casting a shadow, stencil or shadowmaps can both be made to work.

Quote: Original post by Silicon Munky

Quote: Original post by Jarrod1937
2.)The buildings are models too, but since they're not casting any type of stencil shadow it would be safe to assume they're shells.

I don't believe there's anything stopping a shell from casting a shadow, stencil or shadowmaps can both be made to work.

The most common and fastest implementation i've seen of stencil shadows requires closed volumes to work correctly. But you're right, i do believe there are various methods for getting around this limitation, you just get bit of a performance hit in return. Though, perhaps i've just been unlucky and have had the last 3 engines i've worked with use the closed volume requirement implementation.

Quote: Original post by Jarrod1937Crysis for example uses roads made directly into their terrain, this solution worked best for them.

Actually that's incorrect. Crysis's roads are created from actual geometry. In their Sandbox editor, you define a spline on top of the terrain then it generates actual geometry which is NOT based on the terrain at all. The road geometry sits above and conforms to the terrain.

Quote: Original post by soconne

Quote: Original post by Jarrod1937Crysis for example uses roads made directly into their terrain, this solution worked best for them.

Actually that's incorrect. Crysis's roads are created from actual geometry. In their Sandbox editor, you define a spline on top of the terrain then it generates actual geometry which is NOT based on the terrain at all. The road geometry sits above and conforms to the terrain.

Oh really, that is a very interesting method, i'll research that further. Thanks for the info.

Quote: Original post by Jarrod1937
The most common and fastest implementation i've seen of stencil shadows requires closed volumes to work correctly. But you're right, i do believe there are various methods for getting around this limitation, you just get bit of a performance hit in return. Though, perhaps i've just been unlucky and have had the last 3 engines i've worked with use the closed volume requirement implementation.

True, to do stencil shadows you need to have a closed volume, but given a shell you can extrude it in the direction of the light to form your shadow volume. With a shadowmap you can easily render the shell into it.