Billboard Clouds

Post by **jacmoe** » Wed Jul 05, 2006 4:27 am

Falagard wrote:I know how SpeedTree works, I've spent months with it, and implemented my own unique version similar to it, remember?

Yeah, that's me trying to teach your GrandMother to suck eggs.. Sorry.

Thank you for explaining how SpeedTree works. From watching OldBlivion I was able to see it in action. And I don't think it should be a problem when using billboard clouds, because as far as I can see, there's no animating leaves on but up close.
Well, I guess we are waiting for a live demo of it in action.

<edit>
fronds must be another name for billboard clouds, right?
</edit>

Lioric · Post by **Lioric** » Wed Jul 05, 2006 4:33 am

The texture billboard cloud generation is done using ogre, a render system and render texture, that is why its not important if you render your original tree with shaders or not

Post by **Falagard** » Wed Jul 05, 2006 4:34 am

I'm having lots of problems with SpeedTree tree style rendering for various reasons and would prefer to avoid them so this billboard cloud solution is very interesting.

Not to hijack this thread, but I hope these problems point out some of the benefits of using billboard clouds for the leaves:

1. Lower end hardware without vertex shader support - means you have to create two different versions of the same tree if you want to support older hardware.

2. Lighting quads that face the camera is a problem, since they are facing the camera the lighting is wrong.

3. Shadows cast from quads that face the camera is a problem, especially since my current implementation isn't done using a custom movable object factory and only works with a single camera, meaning the quads are oriented towards one camera each frame and don't work with any number of cameras that might render that tree from different directions. Can fix but takes work.

Billboard clouds won't have some of these problems though lighting will still be a bit of an issue.

Clay

Post by **jacmoe** » Wed Jul 05, 2006 4:36 am

@Lioric:

http://www.vrvis.at/vr/billboardclouds/ wrote:We use the simplified models as static levels-of-detail in the medium to far field.

Post by **Falagard** » Wed Jul 05, 2006 4:38 am

The texture billboard cloud generation is done using ogre, a render system and render texture, that is why its not important if you render your original tree with shaders or not

Thanks for the answer, that clears things up a lot. What if the extents of the billboard cloud are calculated by going through all the verts in the original mesh and finding min and max values of the vertex positions, but I'm positioning the verts in my shader and the positions in the actual vertex data of the mesh is not the final position that is rendered on screen?

Post by **Falagard** » Wed Jul 05, 2006 4:42 am

We use the simplified models as static levels-of-detail in the medium to far field.

Ah crap that means that I was wrong about seeing billboard layers for the trunk when I freeze framed it - it must have been really low lod trunk mesh then.

*edit* although I just watched the second video and I swear you can see the cross sectioned tree trunk.

Lioric · Post by **Lioric** » Wed Jul 05, 2006 4:48 pm

Probably when they say "we use simplified models as lods" they refer to billboard clouds with different error threshold to produce the level of detail model

I dont know the exact method they might be using in that video, but the proposed algorithm suggests using the error threshold and the texture resolution to produce the lods

The trunk is created using a "Card Board Plane", so what you have watched in the video is probably correct, although i dont see a reason why you cant use the real geometry for the trunk if you want and dont generate the card boar plane, with little modifications

Post by **Falagard** » Wed Jul 05, 2006 4:58 pm

I must have been tired when I posted these. I re-read the page and he's definitely just saying that they generated simplified models using billboard clouds and use them as levels of detail for distant trees, which implies that you wouldn't use them for near viewing.

He doesn't say that he's using full meshes for near viewing in the video demo, and the video shows that he's not.

SuprChikn · Post by **SuprChikn** » Wed Jul 05, 2006 5:59 pm

jacmoe wrote:fronds must be another name for billboard clouds, right?

frond
n.

The leaf of a fern.
A large compound leaf of a palm.
A leaflike thallus, as of a seaweed or lichen.

Post by **Falagard** » Wed Jul 05, 2006 6:09 pm

fronds must be another name for billboard clouds, right?

Not at all. As SuprChickn stated, fronds in SpeedTree are used for Palm tree type leaves that don't face the camera, for ferns, etc. but also used for fake branch geometry. They don't do dozens of cross sectioned quads for a fronds, it's usually just a few polys.

In my tutorial on how to create trees for GOOF (which as you might know, I've pulled trees out of GOOF so far because of the aforementioned problems) take a look at this picture:

http://www.larabie.net/ogre/MaxScreenshot.jpg

then this picture:

http://www.larabie.net/ogre/MaxScreenshot2.jpg

Some of the branches are full geometry, and others are the fins, or as SpeedTree calls fronds.

Post by **jacmoe** » Wed Jul 05, 2006 8:21 pm

Great!
Can't wait to see this billboard clouds business in real-time!

Joshua · Post by **Joshua** » Tue Jul 18, 2006 12:07 pm

http://graphics.cs.brown.edu/games/Hybr ... hybrid.pdf

Not the most helpful of whitepapers (just an abstract) but it does have some nice screens of mesh trunk + bbc leaves.

swx · Post by **swx** » Fri Jul 21, 2006 3:42 am

I'm just gonna post a small progress report. I'm currently working on implementing the more complex plane selector. There are a lot of things needed for it to work properly, and it's very easy to make some silly error that costs several hours of debugging, but I'll hopefully have it working before the end of the week. Then I need to optimize it, add some different plane modifiers and clean up the code. I'll also add generation of heightmaps for the billboards so that more complex bumpmapping techniques can be used

syedhs · Post by **syedhs** » Fri Jul 21, 2006 8:24 am

Sounds good..

swx · Post by **swx** » Sat Aug 12, 2006 8:18 pm

An update: The billboard cloud generator is basically complete, there's mostly more optimization thats needs to be done, but the generator should work now. Any comments on the interface would be appreciated. I might add so that it can work with existing Ogre roots instead of creating its own if people want it, but since the generation is so time consuming, so I dont really see how it could be integrated into other tools in some good way, so perhaps its best to use it as a stand along command line tool?

I'm thinking about adding support for tree models that have their leaves assigned to various stems in the tree, probably using some sort of xml format. This would allow the creation of billboard clouds that could be used in combination with tree animation. But this will have to be something I do after the summer of code is completed. But since I'll probably use this tool myself, I'll continue updating it even if I dont get money for it

Post by **Falagard** » Sat Aug 12, 2006 10:29 pm

Congrats! Sorry, is this available in Ogreaddons or something?

Command line tool sounds fine.

swx · Post by **swx** » Sun Aug 13, 2006 12:33 am

ogreaddons/billboardclouds in the "ogrenew" branch.

bibiteinfo · Post by **bibiteinfo** » Sun Aug 13, 2006 3:54 pm

swx wrote:ogreaddons/billboardclouds in the "ogrenew" branch.

I think you made a little mistake, it's in the "ogreaddons" branch

swx · Post by **swx** » Sun Aug 13, 2006 4:30 pm

hmm, perhaps... I've just checked it out once, and that was 2+ months ago

Edit: yeah, you're correct, I did a checkout on the ogrenew branch too, so I got it mixed up. So it's "billboardclouds" in the ogreaddons branch

Post by **Assaf Raman** » Tue Aug 15, 2006 11:12 am

It would be nice if you can give the process a progress status while the "Billboard Cloud Generator" generates the end result.

Currently you can't estimate if you are going to wait for a day or only for an hour for it to finish.

swx · Post by **swx** » Tue Aug 15, 2006 10:25 pm

I've added support for a listener that will be notified of events in the build process.

Post by **Assaf Raman** » Wed Aug 16, 2006 10:16 am

I have created a nice tree for you to try out as a good sample.

I have tried to convert it with your project.

No success.

I waited for a long time and the program didn't finish its work on the module.

Do I need to use different settings in the project?

The obj file:http://www.upload2.net/page/download/gb ... e.zip.html

This is how it looks:

pbergeron · Post by **pbergeron** » Wed Aug 16, 2006 5:16 pm

we are interested in evaluating this add-on. can you provide instructions or a help file for its use?

swx · Post by **swx** » Wed Aug 16, 2006 11:39 pm

Assaf Raman: The generator is really slow now since I haven't added the custom memory allocator yet. So expect to wait 15-20min for models like that

Anyway, the newest version has working support for listeners, so you're notified when the generator changes phase and when planes are selected, so you can keep track on the number of faces left to simplify.

My wavefront .obj loader doesnt support multiple materials per object, so the textures for that tree wont be correct... I'm gonna try to fix this tomorrow.

I'll try to start working on some kind of help file or tutorial once I've got the .obj files working properly. The parameters to the generator makes a huge difference both in terms of generation speed and in quality of the output model.

Captain Nemo · Post by **Captain Nemo** » Thu Aug 17, 2006 1:42 pm

Keep up the good work, swx! I am REALLY interested in this project and will try it out soon.

Ogre Forums

Billboard Clouds

progress bar

try this out - a simple tree