#Maps = tons of RAM?
7 messages in this thread
I'm doing an animation for a client who wants quite a lot of devices he
manufactures to be flying by in different (depth)layers. I approached this
problem by scanning in photos of these devices, applying a single colour to the
background of the photos with PhotoStyler, creating from this picture a b/w
mask and combining the two resulting pictures in a material as decal texture
map and opacity map. This material is then assigned in the 3D Editor to 2d
quads of the correct aspect ratio. So far, so good, the result is looking as
expected…
The problem I've encountered now is that this methods costs a
considerable amount of RAM. As I have to render to 1280*960 stills, I scanned
the photos at an average size of 1000*500. The use of 8 different maps leads to
a memory usage of 96 megabytes which is tolerable for the moment (Yes, I was
able to rig my computer up to 96 megs, fortunately…), but what if my client
wants to see 16 devices hovering around in one scene?
Is there a way to reduce the amount of memory used for rendering this
scene? Am I right to understand that 3DS uses a 64 bit colorspace – meaning
that every single pixel of my maps eats 8 bytes? If that's true, is there a way
to switch to 24 bit colorspace? Or do you know another method of doing this
animation? Scaling down the maps won't work as the edges get too jaggy.
In order to calculate the amount of memory used for maps, is there a
formula which can be used not only by the savantry but also by plain people?
<g>
Any help appreciated,
Volker
Hi Volker, <GGG>
first try switching the 'Summed Area' option in your maps dialog to
'Pyramidal'. You won't believe how much memory you can save by doing so. I've
rendered your scene with pyramidally filtered maps et voila – only 35 megs were
used. The result is still absolutely matching your needs of quality, BTW.
Take care (and RTFM, pal!!!)
Volker
Volker:
For your animation you could swap out the larger files with smaller sized 256
color .gif images. For the higher res stills you could just swap out the
gif's for 32 bit .tga's. Saved with an alpha channel, these .tga's could
eliminate the need for opacity maps. I have no idea if this would actually
help reduce RAM requirements but could help reduce the work involved. There
are some guidelines in the manual for calculating RAM requirements in one of
the appendices as I recall.
Bob
Bob, thanks for your reply. I've already tried images with alpha, but
PhotoStyler's alpha channel didn't satisfy me… perhaps I'm using PS not
properly as I just have the Special Edition with a _very_ thin manual…
As for the memory requirements, I've now found the appropriate chapter
(after Gary hinted it out to me…) in the manuals.
Best regards,
Volker
It sounds like you've answered most of your own questions already. (Are there
two of you?)
There's a good explanation for how to calculate RAM usage in the installation
guide. Check it out. You'll see that bitmaps only take up 4 bytes per pixel.
They're all expanded into a 64-bit a-buffer on a scaline basis, but that
doesn't take much extra RAM.
– G
>> (Are there two of you?) <<
Nope. Not beyond the normal level of schizophrenia, that is. <g>
>> …installation guide… <<
[*blush!*] Hubris comes before the fall… What we've got here is the
typical case of a guy whose last thoughts were "Ah bah! What do I need an
installation guide for? It can't be that difficult to shovel the data onto the
harddisk and get the program up and running…"
No, seriously, I did read the installation guide, but somehow the
chapter about RAM requirements must have slipped my awareness. Funny thing,
though. Ten minutes after I uploaded my first message, I've re-read the section
about maps in the reference manual, so I _had_ to answer my own question.
Thanks anyway,
Volker
PS: And thanks for the quick "shooting out" of the IPAS catalogue…
>>Ah bah! We don't need no stinking badges!
– <G>