350z ready for export

[TF]

[edit] Here is a shot showing some of the track resources I've been working on and the new 350z in a very early form:



I've got three weeks off so I thought I would spend some time on graphics. Here's what I've got in mind.

1. A 350z. I want to buy this car so rather than taking a test drive I think I will build one out of polygons and see if I still love it
2. A 240zx. I was watching an old rally car video and it pulled the heart strings. I modeled a 280zx not too long ago so this should be a quick and painless process.
3. A rally track.

#3 would normally be the most difficult but I spent my morning getting in touch with free texture authors and a surprising number of them are willing to give me textures with gpl licenses. Is there any problem giving with giving them credit somewhere in the game or documentation??

I'm thinking of the track needs the sweeping curves of Mosport, the hairpin from Suzuka and the corkscrew from Laguna Seca. Any other suggestions?[img][/img][img][/img]

[reece146]

I'm thinking of the track needs the sweeping curves of Mosport, the hairpin from Suzuka and the corkscrew from Laguna Seca. Any other suggestions?

Lots of elevation changes, lots of sheer cliffs and rock faces, and a high speed section where the trees on either side create a "tunnel" over the road because they touch each other.

[TF]

Such an Ontario request! I'm from the prairies and wouldn't know what a tree that big looks like :wink:

The elevation changes are a priority for me but the trees could be tough. Modeling them can be very time consuming

[joevenzon]

3. A rally track.

That would be great.

#3 would normally be the most difficult but I spent my morning getting in touch with free texture authors and a surprising number of them are willing to give me textures with gpl licenses. Is there any problem giving with giving them credit somewhere in the game or documentation??

Nope, no probem.

[cotharyus]

I like you other work so far - I like it so much I'd like to make a car request - and really, anyone can do it, but the guys will tell you - I don't make many requests for models. But I'd love to have a Shelby Daytona Coup.

[TF]

I've posted some screens at the top of this thread of the models I'm working on.

I'm working on modeling some trees instead of using billboards. Is there any LOD modeling for the track objects? If not, how tough would it be to add? Things would look much better with polygonal trees close up but there wouldn't be a speed hit if we replace them with billboard further out. I've set up a blender scene for quickly generating the billboards and I used it to produce most of the small trees in the screenshot.

The GPL textures I received from a number of authors are really paying off. The new road texture is much higher resolution than the existing roads in vdrift.

[TF]

I won't be able to work on a Daytona Coup any time soon -- the track and car I'm working on now will probably take me well into my next semester. I've added it to my list so we'll see...

[joevenzon]

LOD would be easy to add to the engine. I'm not sure how you'd specify what low detail objects matched up with which high detail objects in blender, though... maybe putting all of the low detail stuff on a separate layer...??

[TF]

I was thinking I could use the lowest detail version in the map itself and then save the high detail versions with the same name and a suffix like _1000 for a version that is accurate from roughly 1000m away. That way the track will work in the current version of vdrift without LOD. It also makes blender's slow real time renderer a little more manageable.

One other thing I was thinking would be cool is batching for the track objects. Once LOD is added batching will allow for hundreds of repeated identical objects like rocks, trees, grass, etc.

When adding multiple identical objects to the track should I duplicate them in blender or is there some way to place them without having to export the identical data a second time? It seems wasteful to have multiple identical .joe files around.

TF

[joevenzon]

When you said this:

I was thinking I could use the lowest detail version in the map itself and then save the high detail versions with the same name and a suffix like _1000 for a version that is accurate from roughly 1000m away.

Did you mean:

I was thinking I could use the highest detail version in the map itself and then save the low detail versions with the same name and a suffix like _1000 for a version that is accurate from roughly 1000m away.

Having a suffix sounds like a reasonable way to go and would be easy to do in the code. Put "LOD" in the suffix somewhere too.

Once LOD is added batching will allow for hundreds of repeated identical objects like rocks, trees, grass, etc.

What exactly do you mean by batching?

When adding multiple identical objects to the track should I duplicate them in blender or is there some way to place them without having to export the identical data a second time?

Placing multiple objects that have the same model data is supported in the engine but not in the list.txt file format. I couldn't think of a good way to make it work when exporting from blender.

By the way, just so you're aware, if you aren't already: there's a version of the exporter in the art package (the one with "all" in the name) that exports the entire scene, not just the selected object.

[TF]

I was hoping to use the lowest-polygon versions in the map itself for 2 reasons:
1. The map will be playable on a low end machine without any need to change the code
2. Blender will be much more responsive with 100 4 polygon trees on screen than with 100 1000 polygon trees.

Batching is a technique supported by modern video cards for rendering geometry very quickly without changing material settings and textures between objects. There's an nvidia article here on it:
http://developer.nvidia.com/object/GDC_2...tions.html

and here's a project that uses batched LOD to render millions of polygons:
http://www.ogre3d.org/phpBB2addons/viewtopic.php?t=5607

[joevenzon]

Okay, lowest-polygon versions by default works, too. As soon as you get something working in Blender let's discuss getting me an exported copy so I can work on adding the LOD code.

Batching is a technique supported by modern video cards for rendering geometry very quickly without changing material settings and textures between objects. There's an nvidia article here on it:
http://developer.nvidia.com/object/GDC_2...tions.html

Ohhh, *that* batching. The benefit to batching is doing all of your draw calls with the same rendering state (same texture, same shaders, etc). On DirectX you have to go out of your way to do batching because DirectX's normal draw calls are extremely expensive. The DirectX draw calls always switch the rendering state, even if it's the same as the last object. OpenGL, on the other hand, has very lightweight draw calls. The OpenGL draw calls don't touch the rendering state, and so you are getting the benefits of batching every time you do another draw without changing the state. In VDrift the engine supports sorting the objects each frame before drawing to minimize state changes, although at the moment it's disabled. This is because with the number of objects in, say, laguna seca, (and on my system) it turns out that the sorting each frame took longer than the time saved by sorting things by texture. I did just get an idea, however, to do sorting only once (instead of each frame) for all of the track objects, since they share the same node on my scenegraph. I'll give that a shot.

[joevenzon]

R1905 has the optimization I discussed above regarding sorting once by render state. It gained one or two FPS for me on my test track (paul ricard) and will probably be even more of a speedup on others. I also found that I was needlessly messing with the transform matrix and optimized that away, which gave me another one FPS or so... not bad.

[cotharyus]

Out standing Joe. Any place we can make progress like that will be good - I've been figuring my laptop would be the lowest powered machine that would be able to run the game, so it'll be interesting to see how that changes things on it.

[joevenzon]

I'm curious too -- let me know how the laptop performs and what its specs are.