archicad texture sizes

[schagemann]

i was just going through the process of downsizing the archicad-library and noticed that some of the provided textures are imho beyond a reasonable size for textures, i.e. some are 1MB-4MB large!
have a look:

ArchiCAD 8.1 folder/ArchiCAD Library 8.1/Textures 81/Roof 81/Roof Tiles 81

additionally they are in tif format, which i find even more surprising - as most textures are jpegs and around 100KB.
although they are really nice textures i would probably expect them as additional goodies and not necessarily included in the standard installation.

am i missing something here? what could be the reason for this...

daniel.

[Rob]

the reason to keep your textures in tif format is the alpha channel for bump mapping. jpg format can not store such information. so, you've got extra channel there + tif does not have as efficient compression as jpg has but it is not lossy which means that texture would not lose the quality after compressing.

Secondly, when loading libraries it DOES NOT mean you are loading all the files into RAM. AC actually stores just names+paths of them. So to speed it up is a problem of the number of library parts not the actually size of them.

[schagemann]

thx rob for your quick reply - however here 2 remarks...

the reason to keep your textures in tif format is the alpha channel for bump mapping. jpg format can not store such information. so, you've got extra channel there + tif does not have as efficient compression as jpg has but it is not lossy which means that texture would not lose the quality after compressing.

1. completely agree with what "alphas" are useful for and what benefits the tif format in general has.
however i do not understand why one would need an alpha channel for archicads built-in renderengine (bump/displacement) - though i think it gets more helpful if you use artlantis and export your atl with textures... but that really is another discussion.
by the way, these files do not have an alpha-channel - though they contain transparent information...

Secondly, when loading libraries it DOES NOT mean you are loading all the files into RAM. AC actually stores just names+paths of them.

2. what i do not understand though is how and where from does the object setting dialogue get all the objects information if you work with a non-local (network) library? or does archicad access our server every time you move an object or generate a 3d-view?

So to speed it up is a problem of the number of library parts not the actually size of them.

3. this makes sense...

daniel.

[Link]

the reason to keep your textures in tif format is the alpha channel for bump mapping. jpg format can not store such information.

This is not actually true. Jpg's can store alpha channels. ArchiCAD can (to a certain level of quality) take advantage of the alpha channel for bump mapping, transparency etc. Tif's are better IMHO, because they don't have the lossy compression and are therefore better quality. 1-4Mb does seem a little too big though. It'd be interesting to see what resolution they are. Unless these materials are going to be very close to the camera, you don't need to go over 150dpi., so maybe you could massage them that way?

Well done on the State of Origin.

Cheers,
Link.

[schagemann]

Tif's are better IMHO, because they don't have the lossy compression and are therefore better quality. 1-4Mb does seem a little too big though. It'd be interesting to see what resolution they are. Unless these materials are going to be very close to the camera, you don't need to go over 150dpi., so maybe you could massage them that way?

well, now this is something... if for example you take the following texture (its one of the standard textures!):
/Applications/ArchiCAD 8.1 folder/ArchiCAD Library 8.1/Textures 81/Roof 81/Roof Tiles 81/Roof tiles 1.tif

1. size: 3.6 MB
2. content: no layers, no alpha channel, nothing visible
3. dimension: 1000px x 1171px
4. resolution: 72 dpi

again i was just wondering...

after all it is not such a big deal, as we have given up on using archicad to render anyway (a step which i can highly recommend) - so i might as well just get rid of those textures all together.

and yes this time the "kiwis" got their fair share...

daniel.

[Rob]

1. size: 3.6 MB
2. content: no layers, no alpha channel, nothing visible
3. dimension: 1000px x 1171px
4. resolution: 72 dpi

again i was just wondering...

I suppose it is a bit too much but I would not get rid of them. Why don't you create a 'special' library with high-res textures that would get loaded at the very end of your design process so it would not slow you down when fiddling with plans/elevations etc and/or could be used just by users who are looking after a draft viz or so.

[david nicholson-cole]

This isnt true. I am surprised you would write this.
JPEGs get rid of alpha channels as the first part of the process of compression. GIFs retain transparency but for web pages. Transparency in gif is not contained in an alpha channel.
the answer for the gentleman with the oversized tifs of over 1000 pixels is to save a new set by opening them in Photoshop, changing Imagesize to something like 200x200 and saving them as a mini version, eg, save Mahogany.tif as Mahogany200.tif. make a new material with this. Its quite good enough for use with Open GL. This would not lose the Apha channels.
Before doing some end renderings, he could reconfigure the material definition to use the high quality tif file.

Link wrote:
This is not actually true. Jpg's can store alpha channels. ArchiCAD can (to a certain level of quality) take advantage of the alpha channel for bump mapping, transparency etc. Tif's are better IMHO, because they don't have the lossy compression and are therefore better quality. 1-4Mb does seem a little too big though. It'd be interesting to see what resolution they are. Unless these materials are going to be very close to the camera, you don't need to go over 150dpi., so maybe you could massage them that way?

[Link]

This isnt true. I am surprised you would write this.

Ouch David!!! Frankly, I'm surprised you'd doubt me!

http://www.heathrowe.com/tuts/jpeg2000.asp

Sure it's not your average JPG, but it is a JPG.

Cheers,
Link.

[david nicholson-cole]

Link wrote:

This isnt true. I am surprised you would write this.

Ouch David!!! Frankly, I'm surprised you'd doubt me!
http://www.heathrowe.com/tuts/jpeg2000.asp
Sure it's not your average JPG, but it is a JPG.

JPEG 2000 isnt supported by the Photoshop or the Archicad that I have. perhaps i need to download that special plugin your webreference mentioned.