Recently I've been trying to create a model of the Valles Caldera supervocano for viewing in Celestia. With some help from John van Vliet, I've managed to implement a "low resolution" (1Kx1K subdivisions: ~1 million vertices) mesh with a few surface textures. I'd like a more detailed model, but the various software packages which I'm trying to use to convert grey-scale height maps into displaced meshes are, shall we say, fighting back. It also doesn't help that my laptop has only 8GB of memory. A 1Kx1K mesh is no problem, but it has to page when Blender exports a 2Kx2K mesh in obj format.

Below are some low resolution screengrabs using a 1K model of the central caldera.

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Selden

got side tracked , and did not post anything

i too have 8 gig ram

16 bit dem's are SMALL
the equivalent resolution mesh is HUGE!!!

Blender handles 2kx2k meshes rather well ( i5 cpu DESKTOP )with 8 gig ram
4kx4k is slow .

for doing anything with a 4096x4096 mesh grid or bigger , you need patience and time

now on a laptop
-- WARNING--
For those that do not already know this ...
a LAPTOP and a DESKTOP intel ( i3,i5,and i7 )
ARE NOT THE SAME!!!

the desktop cpu' are hyper threaded and/or multy core
the laptop ones are different
a desktop i5 has 4 cores
a laptop i5 has 2 cores ( hyper threaded i3 ) to simulate 4 cores


blender can use CUDA but that needs a real full nvidia 3d card with a cuda score of 3 and above
or
it uses OpenCL and needs real !!! cpu cores
--------------------------------------

i sent you a mail about the old blender 2.49b cmod export

for everyone else i have a copy on my g-drive
this DOSE work on Linux and did in xp ( i think it worked on xp)
this DOSE NOT!!!!!! work on win7 and up !!!!

https://drive.google.com/file/d/0B6ZYAd ... sp=sharing
-- needs blender 2.49b , it uses the old python2 API

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"I don't pitch Linux to my friends, I let Microsoft do that for me."
Using OpenSUSE Leap 15 & CentOS 7.6

John,

My laptop has a 1.6 GHz Core i7, so it has 8 threads available. The individual CPUs are relatively slow, though, so importing, translating and exporting large meshes can take a while (5 minutes to load a 2K obj model). I upgraded the hard drive to an SSD a few weeks ago, so the I/O itself is relatively fast.

Unfortunately, though, Blender's CMOD export script is refusing to work for me, and Anim8or crashes when I try to load a 2K mesh. I've posted the problem to the Anim8or forum. Its author has been releasing new beta-test versions frequently, so maybe it'll get fixed "soon".

It looks like I'll be limited to 1K meshes for a while.

Here are some screengrabs showing the full extent of the volcano using a 1K mesh. The central caldera is about 12 miles across.

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Selden

ok update
-- rant-- i hate win7 and the f'ing libraries and even as the ADMIN user i can not edit files programs installed to "program files(86) " !!!!!!
the july reinstall is it
no more !!!!!
the next time win7 IGNORES my settings of NOT auto installing software
( win 7 is NOT!!!!! on the first drive and the ms bootloader is NOT!!!!! on the MBR of that drive -- i hack the bios to update windows )

in july win7 ignored my settings and auto tried to update window's update and write code the the ext4 grub partition( -- that did not work out well for MS ) and the auto reboot it triggered went to grub and not the windows bootloader ( wrong drive and partition) -- not good for a windows update
windows tried to fix it's self by reading the files it tried to save to the ext4 format drive -- did not work out well

basically windows fixed it's self by uninstalling windows update , and a few other things

-- which is WHY i want to INSTALL software and NOT THE OS!!!!! ALL ON IT'S F'ing OWN!!!
i will NEVER reinstall
this is IT!!!!!

the OEM install dvd gos in the trash can



back to the things at hand
the cmod-export for 2.48/9 dose not work on windows 7 ( did on XP )
BUT
the much OLDER!!! cmod-export 2.40 DOSE work

however there is a issue

no texture support !!!
UV YES but NO textures

you need to use "cmodview" to add a texture to the UV ready ascii cmod from the 240 export script

-- on windows
install Blender 2.49b

place the py in
C:\\Users\YOUR_USER_NAME\AppData/Roaming/Blender Foundation/Blender/.blender/scripts/
"cmod-exportmesh240.zip"
https://drive.google.com/file/d/0B6ZYAd ... sp=sharing
WARNING
this is a blender 2.49b script!!!
it uses the python2 API !!!!
it CAN NOT be used on blender 2.75



this works on win7 64
i tested it

_________________
"I don't pitch Linux to my friends, I let Microsoft do that for me."
Using OpenSUSE Leap 15 & CentOS 7.6

John,

Thanks a lot for the older script! (Although it was all for naught )

By comparing the two I was able to modify the newer version (intended for Blender v248) so it works under Win7: I deleted all of the references to "os." Deleting them just removes some of the code which tries to keep you from writing to the wrong file name.

I'll attach a zip of my hacked version.

Unfortunately, however, Celestia can't handle meshes that are so big. It doesn't complain, it just silently doesn't load them at all, continuing on to load other models referenced later in the same SSC.

The ascii cmod for a 2K mesh is slightly over 2GB. The binary version created by cmodfix is slightly under 1GB. The binary cmod for the equivalent 1K mesh (which works fine) is about 60MB. Since Celestia is a 32bit application, I suspect there's some "sanity check" which skips the loading of very large meshes.


*sigh*

I guess I'll have to consider a workaround: either multiple meshes that are "small enough" or some other viewer entirely.

I'm sorry about your frustrations with Win7. Windows Explorer, the desktop file management GUI, is hard coded to protect files in the Program Files directories, regardless of their actual protections. The workaround that I use is to install programs in a different directory (C:\MyPrograms). Some people get around it by using a 3rd party file manager like Directory Opus. To avoid boot-time problems I either use a VM running under VirtualBox or plug in only the disk I want to boot from. It's more awkward than using a multi-boot loader like grub, but I don't have to worry about one O/S messing up the boot-time assumptions of another.

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Selden