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Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 08 Feb 2011, 17:03
by charlie
Found here:
http://opengameart.org/content/mech

Integration status: ongoing

Image

Re: Mech by Skorpio (OGA)

PostPosted: 09 Feb 2011, 15:54
by hc
Here is an in-game picture of the mech with one of the procedurally generated solid camo textures.
The current rendering doesn't use 2d texturing, but 2d texture maps to blend solid material textures from corroded over blank to paint might become handy.

Re: Mech by Skorpio (OGA)

PostPosted: 09 Feb 2011, 23:37
by Skorpio
Hehe, nice. :) So are there only procedural textures atm? I'd also like to play the game, but I'm still waiting for a new windows version of Linwarrior.

And I'm already working on a new mech, but I can't say when it'll be finished.

Re: Mech by Skorpio (OGA)

PostPosted: 10 Feb 2011, 11:51
by qubodup
Woo! new mech! Yay!

Re: Mech by Skorpio (OGA)

PostPosted: 19 Feb 2011, 20:20
by hc
Just want to add that the "Scorpion" will of course be in game with several different camo texture mappings.

@Skorpio:
Could you provide some background info on the robot?
What role on the battlefield do you think this mech occupies?

Re: Mech by Skorpio (OGA)

PostPosted: 19 Feb 2011, 21:08
by Skorpio
I think it's a normal heavy battle mech, best suited for close-medium range combat.

Have you applied the edge split modifier in Blender before exporting the model? On this screenshot the mech looks very smooth, even though the edges should be sharp.

Re: Mech by Skorpio (OGA)

PostPosted: 19 Feb 2011, 23:57
by hc
Haven't noticed the wrong shading but now that you say it...it seems rather obvious.
I guess there were some things that may have gone wrong. Besides I'm not very familiar with blender: The normal calculated in LinWarrior may be flawed, the smoothing groups may be wrong and I was lucky when the conversion worked out the first time (Blender -> obj -> MisfitModel3d).

Re: Mech by Skorpio (OGA)

PostPosted: 20 Feb 2011, 07:05
by Julius
Skorpio {l Wrote}:Have you applied the edge split modifier in Blender before exporting the model? On this screenshot the mech looks very smooth, even though the edges should be sharp.


Regardless of how it looks etc, in general you shouldn't use this so much in real-time rendering as it effectively doubles the number
of vertexes along those edges (and it is actually more the vertex count than the poly-count that matters for rendering speed AFAIK).
The same applies for cuts in the UVmap btw... for every separate edge there, the GPU has to redraw the vertexes.

Re: Mech by Skorpio (OGA)

PostPosted: 20 Feb 2011, 10:36
by Skorpio
I know, but I guess, since the number of vertices is quite low, it won't affect the performance too much. Hc could you do some performance tests with and without split edges? I'd really like to know how much they actually influence the performance. I heard the bottleneck in the graphics pipeline is the rasterization not the vertex transform.

Re: Mech by Skorpio (OGA)

PostPosted: 20 Feb 2011, 10:39
by Julius
Really depends on the hardware platform... but on most of today's hardware you are right, the rasterization (and pixel shader passes) take the majority of the rendering time. However we should keep low end mobile devices in mind, as Linux as a platform is probably more promising there then on the desktop.

Re: Mech by Skorpio (OGA)

PostPosted: 20 Feb 2011, 10:43
by Skorpio
Bah, low end sucks! :)

Re: Mech by Skorpio (OGA)

PostPosted: 21 Feb 2011, 11:39
by hc
As for vertices/normals and sharp edges:
Pushing additional vertices through the pipeline generally costs, yes. And having a hard edge doubles the vertices (normals) at the seam and even more on corners. But I agree that some edges should stay sharp and I am willing to pay the potential price when the quality-cost-ratio is even. Here I think the model loses personality through smoothing. And the blurry desert-camo texture makes the edges even more blurry.

Of course I have to always consider the sum of all things (models, environment, ai, physics) and everything counts but so far I think this model is within a reasonable budget. More detail may be allowed for bigger and stronger mechs, because they may get placed more sparsely. Let's say model A has three times the complexity of model B then it may be reasonable to place groups with three B's and one A. So rarity allows detail. :)

As for modeling quality:
You may model it sharp and if there are any problems I may still smooth the edges. There is no need to model ultra-lowquality because a game requires ultra-lowquality - I consider "modeling data" and "in-game data" two different things where the later is a downsampled/converted/integrated version of the former (with higher sampling quality as time goes by). The first version of LinWarrior ran on a Voodoo Banshee (II ?) and a 300 MHz CPU btw...stone age (or antique - compared to dos software rendering). Open source gaming has to face far longer "shelf" and development lives, not just 2 years [actually IMHO non-free games should consider that, too]. And lower-end-devices may use downsampled versions (LODs).


PS.
The models are finally converted to md5mesh models which may use several vertex weights or meshes anyway and I've kept the rendering stupid: CPU-bound, no vertex buffers and trianglefans and so on. So there is a lot of work that may be shifted away from the CPU to the GPU eventually. Actually the IQM-Format (http://lee.fov120.com/iqm/) may be better suited for robots because it supports explicit normals - with md5mesh the mesh-polygons have to be grouped around edges because normals are derived from vertices at run/loadtime. [...or implement two ways to calculare normals: smooth/flat, according to material]

Re: Mech by Skorpio (OGA)

PostPosted: 21 Feb 2011, 11:54
by hc
If I consider, you may model angled edges (eg instead of 90 degree edges, two edges with 45 degree each), these add model detail and add more/sharper normals even when smoothed - costs about the same as doubling vertices for individual normals but you get more detail.

Re: Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 16 Jun 2011, 16:33
by hc
Here's a picture of the mech with multi-material and sharper edges:

sk1.png
sk1.png (60.21 KiB) Viewed 22779 times

Re: Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 16 Jun 2011, 17:25
by qubodup
sharper edges = much better!

Re: Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 16 Jun 2011, 18:45
by charlie
Yes, it does.

That Mech doesn't look like it would stand up though. The feet are far too small.

Re: Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 16 Jun 2011, 21:25
by Skorpio
I compared the mech with ostriches when I modeled it, and if these freaky birds can stand, then I think the mech can stand, too. :)

Re: Attack Mech (OGA/Skorpio) [integrated]

PostPosted: 16 Jun 2011, 22:36
by qubodup