renderable splines?

[Wazz Pants]

hey does anybody know if HL2 will support renderable splines?
just an idea i have......

 

[Ames]

Basically..no.

 

[Cunbelin]

you mean High-order surfaces ? I doubt it, though DX does support them. In the end they are rendered exactly the same as if you smoothed a model, it just allows for less data to be passed over the bus. Unless you are talking about just a spline curve, in which case there is at least something that works along those lines.

 

[Wazz Pants]

splines as in lines, curves, and 2d shapes.

i wonder if the engine could be modded to render them, or maybe even the exporters would have to be changed as well to export them...

 

[Phisionary]

Being a complete 3d coding ignoramus, I'm betting that that would be a pretty low-level change to be done with a public-release SDK. Possible, I suppose.

 

[Cunbelin]

Well I'd have to point to the wires used in one of the old demos as evidence of some form of vectored art assets being allowed, and I am 99% sure that cameras will work on either Bezier curves, or NURBS as that is generally the best way to create camera tracks.

 

[SidewinderX]

Simple answer, unless TDE corects me, no.

The engine renders polygons and whatnot. Not math-based vectors.

 

[babywax]

Although, if you really wanted to do it, you could use a spline in conjunction with TriAPI, and do the math yourself. Since it's a curve, it would allow you to get infinitely close, and LOD it dynamically.
Why do you want to render splines?

 

[Wazz Pants]

ahh, just using splines would be a quicker way of executing an idea i have... but i can just use meshes anyway and it'll probably turn out looking better.
If my idea turns out the way i want it to i'll show all of you, if not then whatever.

 

[Korgoth]

splines are rendered as cylinders, just use a poly cylinder and extrude it along a spline, 5 seconds, and ya' have it.

 

[Ames]

Well I'd have to point to the wires used in one of the old demos as evidence of some form of vectored art assets being allowed, and I am 99% sure that cameras will work on either Bezier curves, or NURBS as that is generally the best way to create camera tracks.

I have a question about the are the cables/wires (which look FANTASTIC). Especially the way they move in nearby "wind." How does this effect play into map making/model design: do models (like the Alien gunship) have a special flag that means they generate a wind disturbance in their general area? Or does this require some sort of special scripting in C++? Can we make other objects in the game beside the cables/wires react to "wind" or is it an automatic factor of their weight?


From: Gabe Newell
mike?

From: Mike Dussault
Currently, blowing ropes around like the gunship requires specific code in the entity that wants to do it. There is an entity that can create a global wind force for non-rope objects, and it has parameters like wind speed, direction, and noise.


Wow, thanks. I have to say that of all the advances we fans have seen so far, the ropes really "make" many of the visual scenes: they give maps that extra degree of realism that makes them feel truly complex and inhabited. I can't imagine the dock scene or the city scenes being as impressive as they are without them, and the fact that they not only have slack but also can
bounce and twist is truly amazing. How easy are they to create: can you just define two endpoints and give them a certain length or degree of slack?


Yep, that's exactly how they're specified. Here's a little breakdown I wrote about them a while ago:

The ropes are simulated as a set of springs in between the endpoints (usually between 5 and 10 springs). So internally, they look like this:

*-----*-----*-----*-----*

where the *'s are the nodes that the engine cares about. It simulates those nodes, then makes a curve through them to draw the rope.

The nodes respond to gravity and wind. Entities can apply force to the ropes to make them sway. The gunship does this continually, and the strider does this when it takes a step.

For a mod maker, it's easy to make a rope between things (like a grappling hook). You call a function and specify what entities you want the endpoints attached to, the rope length, and the rope material. Level designers can place entities at the endpoints.

Basically, a correction...

 

[Cunbelin]

heh that is exactly how a cardinal curve works, strictly speaking it isn't a full bezier curve nor is it a NURBS curve, it's a similar system.