"Zesty" <tac### [at] gmailcom> wrote:
> I was on the povcomp website looking (okay, drooling) at the grand prize and
> at the bottom of the description, it mentions that it can be used to render
> scenes that would be "impossible with only 4 gig of memory (paraphrased)."
>
> I admit to being very much a novice with Povray, but what scenes take more
> than 4 gig of memory? Has anyone worked on such things, and are they in the
> hall of fame? :)
>
> Just curious,
>
> Zesty

See: http://www.angelfire.com/md2/castlewrks/40/index40.htm

Creating complex scenes with POV requires lots of memory.  The more objects
you have, the more memory is required.  This site is how I got around the
memory requirements to generate a scene with millions of objects in it.
With 4GIG of memory, it may be possible to create this same scene without
using the techniques I used in creating the original image.

More memory also allows for highly complex scenes where you want to create a
scene where the main objects are composed of high numbers of smaller
objects  (TREES, GRASS for example).  When a yard is a big green square
(box{<-20,0,-20><20,.1,20> texture{Green}}, it may look appropriate from a
camera view far away.  As soon as you zoom in close, you have to start
adding in the grass details to achieve a realistic look.

Any advanced POVer knows that to achieve results on a complex scene, you
need raw cpu power, but even more, MEMORY is KING.

Regards,
Robert J Becraft

Post a reply to this message

Becraft, Robert wrote:

> "Zesty" <tac### [at] gmailcom> wrote:
>> I was on the povcomp website looking (okay, drooling) at the grand prize
>> and at the bottom of the description, it mentions that it can be used to
>> render scenes that would be "impossible with only 4 gig of memory
>> (paraphrased)."
>>
>> I admit to being very much a novice with Povray, but what scenes take
>> more than 4 gig of memory? Has anyone worked on such things, and are they
>> in the hall of fame? :)

Also, I recently found that doing fur (with the MayaFur include) -really-
eats RAM - I've got 512 (which is about average to low these days) and
doing even a small patch of fur, dense enough to look nice, is almost
impossible.

But additionally, I might just not know how to use MayaFur well enough yet.
But that's another one - fur implies tens or hundreds of thousands of
objects, and the more RAM you have, the better and more fur you can render.
I suspect!

-- 
Stefan Viljoen
Software Support Technician
Polar Design Solutions

Post a reply to this message

> yet. But that's another one - fur implies tens or hundreds of
> thousands of objects, and the more RAM you have, the better and more
> fur you can render. I suspect!
Assuming you use geometric fur. If you treat fur not as objects but as a
volumetric thing, you can do it with O(1) memory usage.

This post is an advert for my final-year project, which is to patch
POV-Ray to provide fur support (going far beyond what is in the patch
currently in MegaPOV). See my posts in povray.programming, and watch
this space!

Daniel

-- 
A church is more than just timber and stone   .oO( surreal.istic.org )
And freedom is a dark road when you're walking it alone   -Paul Simon,
But the future is now, and it's time to take a stand       'A Church 
So the lost bells of freedom can ring out in my land.      is Burning'

Post a reply to this message

In article <200### [at] dh286pemcamacuk>,
 Daniel Hulme <pho### [at] isticorg> wrote:

> > yet. But that's another one - fur implies tens or hundreds of
> > thousands of objects, and the more RAM you have, the better and more
> > fur you can render. I suspect!
> Assuming you use geometric fur. If you treat fur not as objects but as a
> volumetric thing, you can do it with O(1) memory usage.

Depends on the way you do the volumetrics. You could do it with constant 
memory storage, procedurally based on the object data. Another way uses 
voxel fields, which has memory requirements linear with the volume of 
the fur. You get a tradeoff between memory, time, and quality, as with 
many other things.


> This post is an advert for my final-year project, which is to patch
> POV-Ray to provide fur support (going far beyond what is in the patch
> currently in MegaPOV). See my posts in povray.programming, and watch
> this space!

I haven't looked at your patch yet...have you done any work with 
volumetric long hair? I've achieved some very nice effects with 
model-to-screen techniques, basically drawing lots of antialiased lines 
(the advantage being that you can store a single path and generate 
thousands of hairs from it during rendering), but this has obvious 
problems with reflected or refracted rays. I've been thinking about 
various ways to integrate it into a raytracing engine, including using 
variations of sprites and volumetric methods for reflected or refracted 
rays.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/

Post a reply to this message

> > Assuming you use geometric fur. If you treat fur not as objects but
> > as a volumetric thing, you can do it with O(1) memory usage.
> 
> Depends on the way you do the volumetrics. You could do it with
> constant memory storage, procedurally based on the object data.
Yes, which is why I used the word "can".

> I haven't looked at your patch yet...have you done any work with 
> volumetric long hair? I've achieved some very nice effects with 
There's not much to see yet: it is still in the early stages of being
written.
The aim is to be able to cope with most lengths of hair that people
might want to use. If I have time I will implement several fur-drawing
methods and allow the user to pick one.

> obvious problems with reflected or refracted rays. I've been thinking
> about various ways to integrate it into a raytracing engine, including
Perhaps something along the lines of Lengyel et al. (Real-Time Fur over
Arbitrary Surfaces, Proceedings of the 2001 symposium on Interactive 3D
graphics) would help. I thought this was a pretty good paper. Although
it is targetted to scanline rendering, you *could* raytrace it, and I'm
sure you could adapt the method to suit line hair.

Daniel

-- 
A church is more than just timber and stone   .oO( surreal.istic.org )
And freedom is a dark road when you're walking it alone   -Paul Simon,
But the future is now, and it's time to take a stand       'A Church 
So the lost bells of freedom can ring out in my land.      is Burning'

Post a reply to this message