Transparency and Unexpected Invisibility (By troub

Transparency and Unexpected Invisibility


Amabilis Forum: Microsoft Train Simulator Export: Transparency and Unexpected Invisibility


andnbsp; By troub (208.235.57.205) on Monday, July 30, 2001 – 08:59 am: andnbsp;

Hello,

I’ve been working on this cupola caboose, and it’s going pretty well, although I’ve noticed a disturbing problem. I decided to do much of the detailing, like ladders and rails, using trasparency. My problem is that the transparent textures seem to make EVERYTHING behind them invisible (except for the sky, ground, and track)!

Can anyone help me with the cause of this?

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 09:24 am: andnbsp;

Hi,

Is this the official 4.2 release?

Richard
Amabilis Software

andnbsp; By troub (208.235.57.205) on Monday, July 30, 2001 – 09:26 am: andnbsp;

Richard, I just noticed the same thing on the stop sign that I did a while ago.

Marc from 3Dtrains.com posted this advice in the Loco Design forum of train-sim.com:
andquot;Use another Alpha and not AlphNorm (AlphNorm- perhaps), as the you’ve got is taking priority over SolidNorms in the other objects.andquot;

Should I change the named_shader ( BlendATexDiff ) in the .s file to something else, and if so, what? Or, am I doing something wrong in 3DC?

andnbsp; By troub (208.235.57.205) on Monday, July 30, 2001 – 09:28 am: andnbsp;

Sorry, it’s the 4.2 Pro Beta 1. Should this be fixed in the official release?

andnbsp; By Mike Pye (213.122.149.147) on Monday, July 30, 2001 – 09:44 am: andnbsp;

Richard B,

For information, my 4.2 official still shows beta 1 on my loading screen, but no reference to beta in the ‘about’ screen.

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 10:40 am: andnbsp;

troub,

I can’t say for certain if it is fixed or not. If you send me the stop sign 3DC file I can look at it.

Mike,

Can you give me the file size (in bytes) of the 3DC42.zip file you downloaded?

Richard
Amabilis Software

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 10:50 am: andnbsp;

Mike,

I think that I know what it is. You must uninstall the 3DC 4.2 Beta before installing the real 4.2. Just uninstall and reinstall. All should be OK then.

Richard

andnbsp; By Mike Pye (213.122.44.248) on Monday, July 30, 2001 – 02:17 pm: andnbsp;

Richard,

Sorry if my post was misleading. I’m pretty sure that my version runs as full 4.2, because I’ve picked up the new MSTS Tutorial, but I’ll strip it out and re-install if you think there is any doubt. I was just concerned that if you had forgotten to update the load screen, troub might have been picking up his information about beta from the same place.

However, I have taken a look at the problem troub reported and found the same result with a set of wheels I exported into MSTS. These were freshly modelled, not taken from the conversion exercise we did. I then reloaded the original Scotsman and got as low a view as possible and found that scenery objects do appear to be visible through the wheels in MSTS model and also through the cab transparency. BlendATexDiff is used in both models, so is doesn’t look as though that is directly causing the problem.

I’ll mail you a copy of my wheels file too, in case it helps. But if you tansfer them to MSTS be prepared for the fact that I scaled the size quite significantly to make it easier to see the background through them andnbsp;

andnbsp; By Mike Pye (213.122.44.248) on Monday, July 30, 2001 – 02:19 pm: andnbsp;

Forgot… 3DC42.zip 17,837KB.

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 03:29 pm: andnbsp;

Mike,

Yes, uninstall/reinstall. It is the program itself that wasn’t installed properly. The help would have installed properly.

Richard
Amabilis Software

andnbsp; By troub (208.235.57.214) on Monday, July 30, 2001 – 03:30 pm: andnbsp;

Well, I was using the 4.2 beta (the zip file I installed it from was 3DC42b1.zip). I downloaded the full release today, and the problem persists.

One weird thing, though, is that when looking through the transparent textures, everything seems to disappear except the ground, sky, track, shadows, and THE FLOOR OF MY CABOOSE. You might be able to see from this screenshot:

I converted and looked at the .s files for all of the samples, and I agree it doesn’t look like BlendATexDiff is the problem. How, then, are the material properties saved in the .s file? Hmmmm. We’ll get it figured out!

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 03:33 pm: andnbsp;

I have a couple of ideas I’ll have a look at.

Guess there will be a 4.21 fairly soon.

Thanks for reporting the problem.

Richard
Amabilis Software

andnbsp; By Mike Pye (213.122.16.59) on Monday, July 30, 2001 – 05:07 pm: andnbsp;

Richard,

thanks, I have done the fresh install and it’s okay now. Hadn’t noticed I was building up entries in the Control Panel Add/Remove Programs list andnbsp;

Odd that troub is losing part of his model.. that didn’t happen with the Scotsman nameplate in the conversion exercise.

You probably know this, so forgive me if you do, but

ffeditc_unicode.exe scotsman.s /k

will produce a text version of the original MSTS scotsman.s game file. I notice this file includes 2 shader names:

shader_names ( 2
named_shader ( TexDiff )
named_shader ( BlendATexDiff )

Mike

andnbsp; By troub (208.235.3.207) on Monday, July 30, 2001 – 05:46 pm: andnbsp;

Mike,

It’s important to note that I’m not losing any of my model. The model is there, no problem. The problem is that when looking at a face that has transparency, it’s like looking in a window to an alternate universe! Almost every polygon that should be andquot;behindandquot; the transparency (ie. I should be able to see it through the transparent part of the face), is gone, except for the ground and sky. To get the best handle on what I’m trying to explain, look at the screenshot of the stopsign a few posts ago. The white around the top of the sign is the sky BEHIND the building that is in the background. On my caboose, there’s a large face on the back (and front) that is just a transparency texture to create the ladders and railings. This causes it to look like significant sections of the model are missing, because all faces and objects (except the ground) that I should be seeing through the transparency of the face just disappear instead.

You may have already known what I meant, but if not, I just wanted to clear that up.

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 07:38 pm: andnbsp;

I just checked this out and I think that I know what the problem is. The object you sent me (the stop sign) had depth. I don’t think that works with MSTS. I think if you have translucency or transparency in MSTS that you have to have two polygons, facing opposite directions, against each other. I’m not 100% certain of this though. I could well be wrong.

I just tried making a tree using the two polygon method and it worked fine (actually a trio of two polygon objects rotated to make it look like it has depth). But, in the past I have textured cubes and ended up with the same issue that you have.

Also, make sure that you don’t apply andquot;translucencyandquot; to an object intended to have andquot;transparencyandquot;

Richard

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 08:50 pm: andnbsp;

I may have steered you wrong. I was able to create an object with depth that had transparency. But, if I set translucency I had problems. But the texture I was using did not have translucency, it had transparency.

I think my commment about ensuring that you don’t set andquot;translucencyandquot; when you mean andquot;transparencyandquot; may be the key.

Richard

andnbsp; By troub (208.235.3.207) on Monday, July 30, 2001 – 09:55 pm: andnbsp;

Ok. I’ll fiddle around a little, I’m a little new to modelling. My main confusion at this point then is the difference between translucency and transparency. It may be the key, but what’s the difference?

Should I NOT use the translucency map in 3DC, but still use the alpha channel in my .tga? Should I use the -trans option for makeace or not?

By the way, about the object with depth: for some of those types of objects, I had been creating two faces, rotating them opposite of each other, texturing them, merging and exporting them. Sometimes it was difficult to line them up precisely, and I noticed that if I took a cube, and deleted 4 faces (leaving two opposing faces), I seemed to get the same thing as when I created the two faces (8 points and 2 faces, if I remember correctly). The opposing faces of the cube were already lined up, then.

Thank you very much for your time and effort!

andnbsp; By MRRextreme (172.146.125.80) on Monday, July 30, 2001 – 10:29 pm: andnbsp;

I have not dealt with this transparency issue. Has it been determined what is different about the Scotsman wheel transparency versus the transparency on the caboose railing?

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Monday, July 30, 2001 – 11:07 pm: andnbsp;

Transparency is when you want 100% transparent areas. This is what most people will be using. The only exception likely is for areas that have glass which are usually translucent.

I believe that you want to use the -trans option when making an ace file. But you also have to ensure that your source is 100% transparent (in those areas that are intended to be transparent). You do have to set a translucency map in 3DC and you must set the translucency value to 0. If you set a translucency value to non-zero 3DC will assume that you are using a translucency map rather than a tranparency map and will export accordingly.

This is what I think needs to be done, I don’t know 100% for sure. It worked for me when I used the tree10.ace texture, which I believe was a transparent texture, not translucent.

Richard
Amabilis Software

andnbsp; By ianm42 (212.127.8.122) on Tuesday, July 31, 2001 – 12:52 am: andnbsp;

I have noticed this problem with some objects created with 3D Studio Max, and was starting to think it was a possible reason why the tanker cars supplied with MSTS have solid ladders instead of having the rungs picked out with a transparency map. It may be a problem with MSTS rather than our models. However, I hope a simple solution can be found as transparency maps seem like a good way of creating complex shapes without cranking up the poly count.

Ian M.

andnbsp; By Mike Pye (195.92.168.164) on Tuesday, July 31, 2001 – 03:31 am: andnbsp;

The image illustrates the transparency effect with two models of the Scotsmen wheel (enlarged for clatity).

The top model is one I was working on generating myself and the bottom one was extracted directly from the scotsman2000.3ds conversion that we did.

The texture map, saved as a bmp without the alpha channel was loaded to the ‘Primary Texture’ tab and the alpha channel information, saved in a second bmp file, was loaded to the ‘Translucency map’ tab. The texture was applied ‘relative to the face’ using ‘flat wrap’. The source tga texture map was loaded to the trainset folder as an ace file.

Hope this helps, but Richard will have to expand on the technical issues if needed.

Mike

andnbsp; By Mike Pye (195.92.168.166) on Tuesday, July 31, 2001 – 03:40 am: andnbsp;

Troub,

sorry, did mean lost in the image sense. 5:00 pm on the board is 1:00 am for me andnbsp;

andnbsp; By troub (208.235.3.229) on Tuesday, July 31, 2001 – 09:39 am: andnbsp;

The issue probably does have something to do with translucency vs. transparency, because I converted my .tga without using -trans, and it worked fine:

The problem with this is, as I understand it, using makeace without -trans means you want an 8-bit alpha channel, leaving less room for colors. You can see this in the horrible color quality on the textures. Using -trans means you want a 1-bit alpha channel (which I do). As far I can tell, my alpha channel is just black and white, which should work, right? I don’t have any translucency value set in 3DC, by the way.

I thought my alpha channel had just two colors, but I opened my .tga in PSP, saved the alpha mask to disk, and then opened it, did a color count, and it told me I had 169 unique colors! Ooops. I don’t know how that happened, but I bet that’s what the problem is. I just told PSP to decrease the color depth to 1-bit, now I’ll load that into my alpha channel, convert to ace (with -trans) and see if that works.

Thanks

andnbsp; By ianm42 (194.235.194.91) on Tuesday, July 31, 2001 – 10:46 am: andnbsp;

Oh, so close <!– s:-) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":-)" title="Smile" /><!– s:-) –>

andnbsp; By troub (208.235.3.210) on Tuesday, July 31, 2001 – 10:55 am: andnbsp;

Guess what? I lowered the color count, loaded the new mask into the alpha channel, saved the .tga, converted to .ace WITH the -trans option, and it worked! What happened was when I created my alpha channel, I told PSP to create it from the current image (my texture file). It made everything non-black opaque (the desired result). However, it appears that it antialiased the edges, putting some grayscale into the alpha as shown here:

The one on the left is the alpha I was using, and the one on the right is after I lowered the color count.

Make sure that your alpha channel really is 2 color, even if it LOOKS like it is, you can never tell until you ask your graphics program to tell you how many colors are in the image. *sigh* All this trouble over nothing <!– s:-) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":-)" title="Smile" /><!– s:-) –>. . . .Probably. All I know is that it works as expected now. Thanks Richard for pointing me in the direction to check out the transparency/translucency of my texture!

andnbsp; By Richard Borsheim (Richard_Borsheim) (24.76.55.123) on Tuesday, July 31, 2001 – 05:57 pm: andnbsp;

Well,

It looks like everything is worked out (for now). No changes to 3DC necessary by the looks of things.

I think that MSTS does have very specific requirements for translucency. I would guess that it is this way for performance reasons.

Richard
Amabilis Software

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