new prim type: Height Maps

A height map is very similar to a bump map.

Imagine textureing a greyscale image onto a cube or plane surface. Then pulling out of the surface the parts of the cube where the texture is 'white' and pushing in (or simply not pulling) the parts that are black.

I'm talking small scale, size-of-a-prim here though, not for terrain.

Collisions (For simplicity sake) could just be by the bounding cube of the heightmap.

How would one specify one? I guess just like a prim. You'd drop a 'height map' prim into the world. It would look like a cube. The height map would appear in that cube. You'd specify the height texture and the regular texture, and there you go.

But the things you can do with heightmaps... especialyl if you treat them like a prim and allow people to attach to self... or together to other stuff like any other prim... are so many.

Its called Volumetric Modelling, and its the closest you get to polygonal modelling... without the polygons.

WHY HEIGHTMAPS WOULD SUIT SL

* They are procedural geometry - just like the rest of the geometry in SL

* They cost no additional bandwidth - its just a cube and a texture.

* The level of detail of a heightmap prim could easily be interpolated from low to high simply by changing the subdivision size. Just like any other prim.

* Heightmaps can be subdivided in client side. Just like all the other prims. The calculations are ancient and simple. No additional data needs to be sent per detail level.

* Users would be able to use the same tools as always to make heightmap textures. There are nothing special and no new skills to learn. Its just a texture.

* Using the combination of multiple height map prims, linked togehter, back to back or in other configurations, coupled with alpha textures, users could make convincing, organic looking objects.

* Heightmaps can be any detail level, so it would work on whoevers computer. Just like everything, users could choose how ugly they want things.

Most raytracers and other systems which are based on prims instead of polygons do have heightmaps as a primitive type. It makes sense because you get a LOT of bang for your buck with heightmaps - the computation is simple... the benefits are enourmous.

Imagine a heightmap with texture animation.

Please at least put Height maps up for consideration. I believe they are a primitive type just like spheres, etc, yes , they are slightly different, if they weren't, they wouldnt be a different prim type...

And the possibilities...!!!

At the risk of sounding derivative (is there a calculus pun there somewhere?) ...

I endorse this product and/or service.

=SV

Not to poo-poo a neat idea, but this would turn every prim (with a height map) in to a mesh, or at least, a complicated multi-triangle object, mais-non? (On the client side only, as you state).

Right now primitives are really primitives, and that's what makes the complex geometry of areas of SL bearable for most video cards.

Maybe this would be possible when the new havoc is implemented, since they're already saying it may allow for things to move faster and such.

Almost every primitive is already a mesh, actually.

High resolution meshes, in fact.

If you turn your object detail down to minimal, you'll see the actual triangles that make up the current prims. And each step you put it up increases that number of triangles.

A height map would have no more than any other curvy prim, and it could be lowered or raised in detail by subdividing the surface mesh fewer or more times.

I dont see what the havoc has to do with it - havoc is a physics engine. It'd be pretty bad to try to do collisions with a heightmap. Probably best to just collide with its bounding primitive.

Its still worth it though... the gains you could get from this... I'd have a heightmap anyday, instead of a sphere. You can MAKE most of the primitives we already have, out of a height map or two.

Height maps (or rather displacement maps) would definitely make this world look MUCH nicer. It's been discussed already and I think they did mention that phyysics would be a problem and also that not everyone has a card that natively supports wrapping a height map around a primitive?
I dont know. Im not an expert
Lindens?

Nobody has a card that natively supports height map wrapping.

I wasnt really suggesting being able to wrap a height map around a prim.

Just be able to have a HEIGHT MAP prim.

IE, just a plane, not spehere or cyl or anything... just a plane whos vertices are preturbed by the heightmap.

There is no video card that does that.

There is no video card that does spheres either. Or cubes. Or torii. Its all done by polygons, just like heightmaps would be.

::nods:: I totally endorse this.

My texture abilities, although miniscule, are alot better then my building abilities.
Creating prims out of textures would be an extremely innovative and interesting idea IMO.
It would definately move the aesthetics of the world to an entirely new level; less square, blocky looking things!

==Chris

*cough*
Mezz, you are grossly oversimplifying and probably underestimating modern graphics cards up there.
Plus you seem to have been out of the loop for a while. Displacement mapping is a standard DX9 feature present on the FX line of cards and also in the Matrox Parhelia. ATi also has them but I'll be damned if I grok their model numbering scheme. 9700 has it, so I suppose the improved 9800 also should have it. I dont know about their lower-end cards but I think they are probably feature-complete, but slower.
The problem is that people dont upgrade their hardware very often so some of them wouldnt be able to see our pretty displacement maps.

Oh, I know what displacement mapping is. I do graphics stuff, especially directX9 shader work. However, I wasn't speaking about displacement mapping at all.

I know it is very similar to heightmapping, but done in hardware... For the last 20 odd years though, height mapping has been used in games without any kind of advanced hardware acceleartion.

Displacement mapping is a way to do heightmapping in hardware on a per pixel basis. Per pixel! Its amazing stuff, I grant that, but its not height mapping, and it requires special hardware to do - heightmapping does not.

Displacmeent mapping would be the ULTIMATE of course, it looks even better.

But thats even better, isnt it? Because it means that... heightmapping can be done by SL on peoples whos video cards do not support displacement mapping. And height mapping is FAST.

Those who do have the displacement map support could have their video card do it for them. FAST.

Height mapping is generally per vertex, but is like displacement mapping in most other respects.

I like this idea.

I want to make a rippling waterbed with an animating texture