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Outerra Tech Demo download. Help with graphics driver issues

Author Topic: Collision Mesh  (Read 4737 times)

Beolex

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Collision Mesh
« on: April 02, 2010, 01:18:21 am »

You may or may not be familiar with many game terms, but a collision mesh is something that needs to be explained just in-case you don't know what I am referring to.

Lets say you want to make a very detailed 3D Model and import it into the game:



But, when you integrate it into the game, it has a lot of polygons and makes your frames-per-second low because of all the detail it has. Maybe you can make a replacement mesh, but it doesn't replace the model, it replaces the physical properties:



So that blank house would replace the model. But it wouldn't replace the model itself, only the way it behaves in-game. If you've ever played Need For Speed Underground (or any of the series after that), you might try to drive through a garage or through a narrow street, but it blocks you. That's a collision mesh, it's just a substitute for the old high-polygon mesh.

This might involve a little bit of editing of files once exported, but if you know what you are doing, perhaps you can make some really great [detailed] models yet get very good framerate ingame. I like to make my models detailed (I have 1.5+ years experience in Sketchup, little in 3DS Max), and once the COLLADA importer works, I would like to get some of my stuff in-game.

But I want it not to lag a lot, so this collision mesh could really be helpful, and this way we can have more objects on the terrain without all of the lag and slow-motion due to high polygon/detailed models.

Here is an image to explain:
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cameni

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Collision Mesh
« Reply #1 on: April 02, 2010, 07:09:15 am »

Surely we know what's a collision mesh ;)
What did you want to say? You want to have detailed meshes without impacting performance by using the same mesh for collision. The importer will actually yell at you if there's no collision mesh or a bounding collision primitive(s) included for the model. Also we are thinking how the LOD for models will be handled, in a way that is compatible with modern high performance rendering requirements. The process may be automatic or the different levels of detail can be contained within the file.

Btw anyone interested to make a set of buildings for upcoming city rendering test/video?


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Beolex

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Collision Mesh
« Reply #2 on: April 02, 2010, 07:34:49 pm »

Ah, good to see you comprehend the concept. It's very hard to explain, so I am glad you understand. So yes, I want to have detailed meshes WITHOUT impacting the performance. This can save much performance yet getting the detail of an immaculate map. It will also be interesting to see how the process will be automatic. But I hope it all turns out well...

I could make models in SketchUp (I have 3DS Max 2009, but not learned it yet) but it has no ambient occlusion and not a good texturing system. Also, CG Textures (a site for building textures) does not allow them to be redistributed in open-source projects according to this line out of their policy:

Quote
May I use your textures to make a (commercial) computer game?
Yes--with the exception of Open-Source projects. See below.

Therefore, If I use the textures on your game, you could risk being accused of using textures without a valid license. I can make blank (uncolored/untextured) buildings and you can add your own.
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cameni

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Collision Mesh
« Reply #3 on: April 03, 2010, 01:01:09 am »

Well this is not an open-source project, I don't know how their license applies to projects that are open to extensive modding or based on user content.
Anyway, this is only for the test and the video. We already have untextured models, and we are looking for textured ones that use repeating for windows so that they look good even from close distances.

The test is about instancing performance, so there will be few types of buildings - one or two sky-scrappers, then something half the size, and 3 kinds of apartment houses. 1200/800/500 triangles approximately, and as few textures as possible (shared).
The buildings will be placed randomly but using a fractal to determine the layout so that high ones are grouped in one location.
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Beolex

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Collision Mesh
« Reply #4 on: April 03, 2010, 02:21:49 am »

I have sent you a forum email with more information. Thanks for the quick + informative replies!
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