scott <sco### [at] scottcom> wrote:
> > Actually, among other things, I started getting into some 3D programming thanks
> > to: a previously downloaded version of Fragmentarium (guidance); a C++ compiler
> > & libs; GLSL documentation; POV docs. You know, raytracing via raymarching is
> > actually a lot easier to achieve than traditional raytracing due to the fact
> > that to make objects you pretty much just produce shape functions, and to render
> > you increment a ray variably from the camera until you reach a function's
> > threshold (as apposed to developing intersection functions for different shapes
> > and using octree optimizations). There's more to it of course, but the point is
> > it's simpler (to me anyway). Unfortunately, rendering on the GPU is much more
> > limited due to video memory. But hey, real-time isosurfaces! Yeah!
>
> Yes you can create some really cool effects that way, especially things
> like repetition essentially come for free. Being able to watch your CSG
> isosurface repeated off to infinity in every axis and be able to explore
> around it in real time is pretty cool.

Yeah, it's neat alright. But you've got to bump up the maximum number of ray
steps for that, or else the surfaces beyond the edges of closer geometry tend to
disappear.

There are possible extensions to that concept as well, such as adding randomized
transformations per cell, or even picking new objects from an array of unique
distance estimate functions. Neighboring cell evaluation is needed for that,
though, since the DE needs to remain as continuous as possible.

> I tinkered about using shadertoy.com as it allows you to write your
> shader code immediately without having to fuss about with pages and
> pages of C++ boiler-plate code just to get a blank screen rendered. Some
> people have made some amazing creations on there.

Yeah they have. I created a couple of things a while back (look for
BeyondTheStatic), but nothing too great. My Mode7 attempt was cruddy, but it
served its purpose. I'd like to get some more stuff uploaded there soon. One
idea involved displaying numbers without font files. It could help shader
programmers who need to read variables but can't add new input textures.

> Also you can always write your raymarcher to run on the CPU, it won't be
> as fast but if you're running into memory troubles with a small GPU it
> might allow you to do things not possible otherwise.

True, but the complexity of the DE is also a problem, even with more memory.
Could still be worth it.

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