Massive textures are they worth it? Are bump maps better?

[NeilF]

Code: Select all

Besides Linux/Unix, the script also runs in a current Cygwin installation
under Windows, ( http://www.cygwin.com ). If the z-shell ('zsh') is unavailable,
it also may be executed with the 'bash' shell, by replacing #! /usr/bin/zsh by
#! /bin/bash in the first line.

The script assumes that a recent version of the ImageMagick package
( http://www.ImageMagick.org ) is installed (either under Unix/Linux or Windows).
The utilities 'convert' and 'identify' of that package are used.

You may increase the pixel cache size $maxmem from the 80 MB default
value to e.g. 80% of your RAM size within the script with an editor.
This will speed up the performance of 'virtualtex' considerably.

On a PIII/512MB RAM the tiling of a 16k x 8k texture into
32 (2k x 2k) tiles now only takes 15 minutes with a Linux OS!

Author: Dr. Fridger Schrempp, fridger.schrempp@desy.de
Version: 1.03, 08/16/03



So, suppose you got a 16k PNG texture, and want to chop it into 1024 pix sized tiles in PNG format, just type at the prompt:

> virtualtex <16k-texture.png> 1024 png

You have to repeat this procedure , of course, with all the other required textures that are smaller by factors 2^n. There are plenty of respective explanations available in the forum. The associated 8k,4k,... textures you just rescale trivially (with /bicubic mode!!) in photoshop from your biggest 16k texture.

Since the DOS- shell grammar is too stupid for that task, I had to write 'virtualtex' for advanced UNIX/Linux shells like zsh or bash. So you got to install a CYGWIN linux layer under Windows to have it run. I suppose you know what CYGWIN is. It's very easy to install. This should be extremely easy with your professional knowledge...You also need to install ImageMagick. It is free and exists for native windows, Cygwin-Linux and native Linux.


Good luck,

Bye Fridger

Thanks for all the help... Still don't understand if so many people do this why there isn't a sticky dedicated to it etc... eg with a step by step example... Your script wasn't even easy to find... (it wasn't even on your website?)

Thanks again...

[t00fri]

...
Thanks for all the help... Still don't understand if so many people do this why there isn't a sticky dedicated to it etc... eg with a step by step example... Your script wasn't even easy to find... (it wasn't even on your website?)

Thanks again...

NeilF,

looking back over your actions through the last several days since you are a member of the forum, I would say that you are just a bit to fast and|or impatient,....before giving up and asking for people's help (time...).

If you are a software expert, it is hardly understandable to me, why you did not localize within less than 1 minute my latest 'virtualtex' script, 1.04.??

I just re-did the obvious out of curiosity, typing 'virtualtex' into the search engine. And of course, the most recent reference is what you want:

http://www.shatters.net/forum/viewtopic.php?t=6769&start=16

Please, could you detail a bit why my script "wasn't easy to find"?

Moreover, you criticized the lack of 'sticky' step-by-step instructions.
People like you should best do such a job. I did the script and tested it. That's fair enough...

There is actually a sticky post: "Virtual Textures for Dummies" where you find much reference to applications of my script and the installation of CYGWIN. Bob Hegwood, even wrote a nice step-by-step document, the URL of which is presently dead, unfortunately. That sticky post you also find right away by typing 'virtualtex' into the search facility.

But come on, YOU should not need such step-by-step stuff. At least you said you were a programmer. What do you program actually??

My Website from my profile is my /professional/ WEBsite. That's what people used to put there when I entered the forum 3 years ago. That site has to be strictly reserved for professional matters. My Celelstia site is on Chris' machine and also hosts virtualtex, the TextureFoundry and many other things.

Bye Fridger

[DaveMc]

On motherlode and elsewhere on the net you may find a lot of crab

We can get crab on the motherlode?? Cool! I'm in the market for some fresh Alaskan King.

[t00fri]

On motherlode and elsewhere on the net you may find a lot of crab

We can get crab on the motherlode?? Cool! I'm in the market for some fresh Alaskan King.

We can talk German if you prefer.

Bye Fridger

[danielj]

Fridger,
You do have a huge computer with tremendous power.What about your VGA and HD?

[He (and I) have Mars textures + matching Normal maps up to 46k...]

arrgghhh.... want them....
(crying baby in deep depression...)

No I'am kidding, I won't ask for them...

...

please?

Well these are Marios "commercial" files, each texture being almost 3GB in size!! So with /asymmetric/ ADSL lines, /uploading/ is impossible, clearly.

Also you need special computer setups to be able to load such monster textures into memory to make changes. I have 3GB of CL2 RAM, for example and a fast 3.2 GHz P4 machine with a top-speed HD. So does Mario...

Notably also the 48k specular textures of Earth are incredible. You can see the sun reflect beautifully in small rivers and tiny lakes etc.

We have spent a considerable amount of joint research in exploring ways to make the normal (bump) maps optimally smooth and free of NOISE. For that purpose, one has to start from the /original/ 16bit level maps and do the 8bit truncation (required by Celestia) only as the /last step/ in the chain of image manipulation steps. Chris' 'nm16' normal map converter directly takes those scientific 16bit RAW level maps as input. I.e. altitudes are not encoded in 256 steps (8bit), but rather in 65536 steps (16bit). So the altitude patterns are incredibly more smooth, of course.

Another procedure that we explored to reduce the noise, was to stack many textures with random noise injected on top of each other in various modes (multiply,....). This technique is well proven in astronomical CCD or video photography. The stacking technique can enormously enhance the signal to noise ratio!

Bye Fridger

[t00fri]

Fridger,
You do have a huge computer with tremendous power.What about your VGA and HD?

My graphics card is pretty fast but not the very latest model:

NVIDIA FX 5900 Ultra /256 MB

My HD has a transfer rate of ~ 60 MB/sec (ATA 133) and a pretty fast access time.

Bye Fridger

[PlutonianEmpire]

NeilF,
Wrong. The Bumpmaps or as most of us use Normalmaps now only give a simulation of elevation and usually it is the most noticeable from near the planets terminator ( shadow line ). The Mars textures you are showing pictures of have shadows already in the texture so it is not really giving you right idea. The texture shows the detail not the bumpmap. If a texture is only 4k and you use a 16k bumpmap you are still going to see the 4k texture. It will look now where as detailed as per say a 16k texture with a 16k bumpmap.
Let me show you some examples.

First here is a 4k Earth texture no bump


Next same texture with a 16k bumpmap


Next the 16k version of the texture with no bump


Next the same 16k texture with 16k bump


As you can see there is a big difference if you look at the coast lines and other inland areas. The lower the texture size the lower the detial the bigger the texture the higher the detail. It is all a matter of finding a balace of texture size and bumpmap size that your graphics card can handle and that you are happy with. I personaly say an 8k texture is the lowest I am willing to use for the Earth or Mars but I normaly use 16k textures of these with 16k normalmaps. Of course I have a GeForce FX 5900 so I can handle these textures. With a different card your millage may vary.

Don. Edwards

One question. Why is europe covered in ice?