+- LDraw.org Discussion Forums (https://forums.ldraw.org)
+-- Forum: General (https://forums.ldraw.org/forum-12.html)
+--- Forum: Official File Specifications/Standards (https://forums.ldraw.org/forum-32.html)
+--- Thread: Extension for material properties? (/thread-24221.html)
Extension for material properties? - N. W. Perry - 2020-09-30
I had this topic in mind, when I stumbled on this very old thread. With the vastly increased use of photo-realistic rendering since then, I'm wondering if the subject has been given any more thought?
In particular, I've found that there's a fair number of parts that are made of a softer plastic than the typical ABS brick, and/or have a rougher, matte finish (like the slope texture that kicked off that thread). While there are already color categories for rubber, various metals, etc., there seems to be a lack of options for describing different solid plastic properties within LDraw.
As a more general note, this seems like another in a family of physical part characteristics that I could envision being described by a series of metadata extensions, possibly as part of a hypothetical LDraw 2.0. Others in the family could include snapping/connectivity info, physical part dimensions (for accurately rendering seams, or calculating part collisions), and kinematic info (for describing technical functions like gear meshes).
RE: Extension for material properties? - Gerald Lasser - 2020-09-30
Yes, I agree, it is about time to pick this topic up again after 9 years.
Especially when I did now the Technic Panels of the Lamborghini I noticed this with the test renders again they are too shiny when rendered with Stud.io
concerning Studio, they do have a small shadow library, e.g. for some slopes, where they add the typical pattern. I think they take the LGEO data for that.
RE: Extension for material properties? - Magnus Forsberg - 2020-09-30
(2020-09-30, 21:13)Gerald Lasser Wrote: Yes, I agree, it is about time to pick this topic up again after 9 years.
But I think we all agreed on that no added info should be forced into the dat-files.
We don't want to recycle any file to add any metadata info.
RE: Extension for material properties? - N. W. Perry - 2020-09-30
(2020-09-30, 21:24)Magnus Forsberg Wrote: But I think we all agreed on that no added info should be forced into the dat-files.
We don't want to recycle any file to add any metadata info.
Yeah. By "metadata" (and perhaps I'm misusing the term), I mean something separate and apart from the "data"—just as shadow libraries are now used. A user could add the info to any part, either in a joined file or by appending the .dat file itself, but no .dat would be made non-compliant by not having it.
RE: Extension for material properties? - Willy Tschager - 2020-10-03
(2020-09-30, 21:24)Magnus Forsberg Wrote: But I think we all agreed on that no added info should be forced into the dat-files.
We don't want to recycle any file to add any metadata info.
We never agreed if information should be stored in a parallel library or just one file:
https://news.lugnet.com/cad/?n=11226
and we never will. I gave up on the topic and you should do the same.
w.
RE: Extension for material properties? - Orion Pobursky - 2020-10-03
(2020-10-03, 8:05)Willy Tschager Wrote: We never agreed if information should be stored in a parallel library or just one file:
https://news.lugnet.com/cad/?n=11226
and we never will. I gave up on the topic and you should do the same.
w.
I really think we should pull in and officialize (or, at least, officially bless) all the common meta commands (snapping, flexible parts, and instructions) and Roland's shadow library.
RE: Extension for material properties? - Gerald Lasser - 2020-10-03
I actually like the proposal in the "very old" thread, i.e. having a material start meta and end meta.
I got now the Trolls container, which is opaque on the outside, i.e. slightly rough, but on the inside it is shiny ABS. That's not a simple material property that can be applied to the part in general.
Some materials are covered by assigning a special color, like Rubber or metal
RE: Extension for material properties? - Roland Melkert - 2020-10-03
(2020-10-03, 18:44)Gerald Lasser Wrote: I actually like the proposal in the "very old" thread, i.e. having a material start meta and end meta.
I got now the Trolls container, which is opaque on the outside, i.e. slightly rough, but on the inside it is shiny ABS. That's not a simple material property that can be applied to the part in general.
Some materials are covered by assigning a special color, like Rubber or metal
We already have a material start/end meta (sort of), it's called the texture extension.
It just needs some changes to make it work with in a different mode.
Maybe introduce a new meta name which is backwards compatible with the texture one. So parsers don't need to support jet another begin/end/next mechanism. They would only need to disable part of it's parameter handling etc when the meta is called texture instead of e.g. 'material'
RE: Extension for material properties? - Philippe Hurbain - 2020-10-04
(2020-10-03, 19:18)Roland Melkert Wrote: We already have a material start/end meta (sort of), it's called the texture extension.Then there is a need for some nesting, which is currently excluded from texmap specification: eg. we need to be able to apply texmap pattern on grainy slopes (BTW, what happens in various implementations if we try to apply texmap on something containing a subpart itself texmapped?)
It just needs some changes to make it work with in a different mode.
Maybe introduce a new meta name which is backwards compatible with the texture one. So parsers don't need to support jet another begin/end/next mechanism. They would only need to disable part of it's parameter handling etc when the meta is called texture instead of e.g. 'material'
Speaking of materials, we still don't have satisfying way to use texmap patterns containing metallic inks...
RE: Extension for material properties? - Magnus Forsberg - 2020-10-04
(2020-10-03, 18:44)Gerald Lasser Wrote: Some materials are covered by assigning a special color, like Rubber or metal
How many of these properties could be placed in ldconfig?
IMO we are missing colour codes and properties on textile materials.