Invisible texmap pattern

[Magnus Forsberg]

This part

is now present at the Part Tracker, but the TEXMAP pattern is not visible from behind, when I use it in LDCad, on a transparent part.


Is it possible to combine a TEXMAP pattern with a BFC NOCLIP ?
If so, how should a correct file syntax look like?

[Travis Cobbs]

This part

is now present at the Part Tracker, but the TEXMAP pattern is not visible from behind, when I use it in LDCad, on a transparent part.


Is it possible to combine a TEXMAP pattern with a BFC NOCLIP ?
If so, how should a correct file syntax look like?

First of all, please note that the same thing happens in LDView. In LDView, it's definitely due to a bug. (Unfortunately, it's a bug that would take a VERY long time to fix, and probably won't be fixed.) The bug in LDView is that LDView doesn't support TEXMAPs being applied to transparent surfaces, so the surface the texture is on is opaque. The reason that this relates to BFC is that in LDView, BFC is never applied to transparent surfaces. So if it weren't for this bug, the texture would be visible from the back side in LDView.

I'm not sure what happens in LDCad. It could be that LDCad applies BFC to transparent surfaces. If so, I would argue that that is a bug. It also could be that LDCad doesn't support TEXMAP on transparent surfaces. That would also be a bug.

The following might work, but isn't appropriate in an official file, since the disappearing texture is due to a renderer bug and not a part bug:

Code:

0 Dish  4 x  4 Inverted with White and Aqua Swirl Pattern
0 Name: 3960p0b.dat
0 Author: Philippe Hurbain [Philo]
0 !LDRAW_ORG Unofficial_Part
0 !LICENSE Redistributable under CCAL version 2.0 : see CAreadme.txt

0 BFC CERTIFY CW

0 !KEYWORDS Round, Elves

1 16 0 0 0 1 0 0 0 1 0 0 0 1 s\3960s01.dat
0 !TEXMAP START PLANAR -40 0 40 40 0 40 -40 0 -40 3960p0b.png
0 !: 1 16 0 0 0 1 0 0 0 1 0 0 0 1 s\3960s03.dat
0 !: 0 BFC INVERTNEXT
0 !: 1 16 0 0 0 1 0 0 0 1 0 0 0 1 s\3960s03.dat
0 !TEXMAP FALLBACK
1 15 0 0 0 1 0 0 0 1 0 0 0 1 s\3960p2b.dat
1 16 0 0 0 1 0 0 0 1 0 0 0 1 s\3960p2a.dat
0 !TEXMAP END

For reasons that I don't understand, the above doesn't work in LDView. I will be investigating that. What it's supposed to do is include a second copy of the textured geometry, and have that second copy face the opposite direction. It doesn't work, and I don't yet know why.

[Roland Melkert]

For reasons that I don't understand, the above doesn't work in LDView. I will be investigating that. What it's supposed to do is include a second copy of the textured geometry, and have that second copy face the opposite direction. It doesn't work, and I don't yet know why.

I won't show in LDCad ether, not because the texture isn't rendered (it does show if you remove the s\3960s01.dat line, but because of the rendering order I think.

Transparent parts aren't 100% in LDCad ether indeed, I've had a discussion about this very part with Philo this week as he expeted the patterned part of the png to be non transparent even for transparent parts.

I'm going to make some tweaks for the next version but I doubt it'll be perfect as I'm currently restricted by the fixed OpenGL pipeline. The 2.0 rendering engine will use all custom shaders so things should be better once that gets going. Hopefully just in time for official parts using textures

edit: confirmed, for LDCad, it is/was the rendering order I swapped something around and now Travis' version does show the texture on both sides.

[Travis Cobbs]

For reasons that I don't understand, the above doesn't work in LDView. I will be investigating that. What it's supposed to do is include a second copy of the textured geometry, and have that second copy face the opposite direction. It doesn't work, and I don't yet know why.

Well, I've discovered that textured geometry in LDView apparently isn't paying attention to BFC INVERTNEXT (at least not when it's two levels of indirection away), so that explains why the code I supplied isn't working. That's a bug I should hopefully be able to track down and fix.

[Magnus Forsberg]

Any development in the bug hunt here?.
Is the syntax in the file correct, or do we need to change the part?

[Travis Cobbs]

Any development in the bug hunt here?.
Is the syntax in the file correct, or do we need to change the part?

In my opinion, the part is correct.

[Roland Melkert]

Any development in the bug hunt here?.
Is the syntax in the file correct, or do we need to change the part?

In my opinion, the part is correct.

I agree, but we might need to clarify the texmap spec on how transparent parts should be rendered.

[Joshua Delahunty]

This part

is now present at the Part Tracker, but the TEXMAP pattern is not visible from behind, when I use it in LDCad, on a transparent part.


Is it possible to combine a TEXMAP pattern with a BFC NOCLIP ?
If so, how should a correct file syntax look like?

For anyone following this now, now that the part is official and off the parts tracker, you need to download the texture from here (took me a bit of digging, thought I'd help the thread)

http://www.brickshelf.com/gallery/Philo/...960p0b.png

[Merlijn Wissink]

This part

is now present at the Part Tracker, but the TEXMAP pattern is not visible from behind, when I use it in LDCad, on a transparent part.


Is it possible to combine a TEXMAP pattern with a BFC NOCLIP ?
If so, how should a correct file syntax look like?

For anyone following this now, now that the part is official and off the parts tracker, you need to download the texture from here (took me a bit of digging, thought I'd help the thread)

http://www.brickshelf.com/gallery/Philo/...960p0b.png

The actual images aren't included in the library? 

[Chris Dee]

For anyone following this now, now that the part is official and off the parts tracker, you need to download the texture from here (took me a bit of digging, thought I'd help the thread)

http://www.brickshelf.com/gallery/Philo/...960p0b.png

The actual images aren't included in the library? 

Not at the moment.

I need to do some work to the Parts Tracker and the LDraw parts update creation process to be able to support TEXMAP image files.

[Philippe Hurbain]

Loosely related: it would be nice have a mechanism to embed (unofficial) textures in mpd files!

[Merlijn Wissink]

The actual images aren't included in the library? 

Not at the moment.

I need to do some work to the Parts Tracker and the LDraw parts update creation process to be able to support TEXMAP image files.

Ah, I see. I'm a bit out of the loop as far as texmap is concerned. 
Does anyone have a separate zip file containing all the images currently used in (un)official parts for the time being?

[Philippe Hurbain]

Does anyone have a separate zip file containing all the images currently used in (un)official parts for the time being?

AFAIK I'm the only author of texmapped parts, so this should be complete:
https://drive.google.com/open?id=1CemtiE...YoHDJoD3Sl

[Joshua Delahunty]

This part

is now present at the Part Tracker, but the TEXMAP pattern is not visible from behind, when I use it in LDCad, on a transparent part.


Is it possible to combine a TEXMAP pattern with a BFC NOCLIP ?
If so, how should a correct file syntax look like?

This thread encouraged me to take stock of current TEXMAP support among the renderers I know of.

FOUNDRY
Foundry allowed the transparency of the part to "transfer" to the opaque portions of the texture, and so made the texture transparent; this was a bug.  Foundry was fixed through use of a "double render" fix.  I expect that a true fix will only come with multi-texturing (though I'm not speaking to that as an expert by any means).  The fact that our proof-of-concept framework app for TEXMAP didn't do this right was concerning.

Unfortunately, this fix did "break" the ability to see the texture from "behind" the transparent part.  The rendering pipeline is being worked on in Foundry, and we hope to get both of those working, plus implementation of shaders to continue to add rendering features.

STUD.IO
Stud.io does not appear to support texture mapping at this time.  The LDRAW directory they use does not feature a parts/textures/ directory.

BRICKSMITH
Bricksmith renders the opaque portions of the texture transparently, and does not show the texture "through" the transparent part.
NOTE: I'm pretty sure Bricksmith only does PLANAR at this point.

LDCAD
I'm not able to test LDCad from my Mac.  I understand that things are better, but the true improvement will come with LDCad 2.0?
LDCAD is the only package supporting CYLINDRICAL and SPHERICAL mapping at this time.

LEOCAD
LeoCAD had its issues when I started testing (it would actually crash on TEXMAP references; whereas an earlier version had worked fine).  Leo fixed that, plus has it rendering opaque portions opaquely, and you can see the texture through the part from the "back."

There are still some sorting issues that occur occasionally, so if you have a TEXMAPped part behind a transparent TEXMAPped part, sometimes from certain angles the TEXMAP of the background part will render fully opaquely in the foreground.  I had to hunt to see this issue, personally.

Generally, though, LeoCAD currently has the best render, which if I'm not mistaken is partially because he's doing shader operations to get it to work. LDCad 2.0 is due to do this as well, I think?

Leo is working towards CYLINDRICAL and SPHERICAL mapping next, and is considering OBI (a different but similarly designed feature) as well.