Author Topic: CoronaBitmap - mirror tiling mode behaviour  (Read 9837 times)

2015-06-03, 16:54:22

Ludvik Koutny

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4. using mirrored instead of repeated tiling works wrong as max bitmap: it use half size scale; can Corona work better than max in this? ;)

It should be this way to make conversion from Max Bitmap to CoronaBitmap easier, and also to make easier to support 3ds Max Bitmap directly in the future. It's not obvious but mirror is actually not bitmap transformation but rather tiling modes. There are 3 tiling modes: No Tiling, Normal Tiling and Mirrored tiling.

To simply flip map horizontally or vertically, you can simply set scale to negative value. So to flip the map horizontally, just set U scale to -1. Works for both 3ds Max Bitmap and CoronaBitmap, but in CoronaBitmap it may still be a little buggy, so give us some time to fix it :)
« Last Edit: 2015-06-07, 08:23:32 by romullus »

2015-06-05, 09:42:09
Reply #1

Alessandro

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4. using mirrored instead of repeated tiling works wrong as max bitmap: it use half size scale; can Corona work better than max in this? ;)

It should be this way to make conversion from Max Bitmap to CoronaBitmap easier, and also to make easier to support 3ds Max Bitmap directly in the future. It's not obvious but mirror is actually not bitmap transformation but rather tiling modes. There are 3 tiling modes: No Tiling, Normal Tiling and Mirrored tiling.

To simply flip map horizontally or vertically, you can simply set scale to negative value. So to flip the map horizontally, just set U scale to -1. Works for both 3ds Max Bitmap and CoronaBitmap, but in CoronaBitmap it may still be a little buggy, so give us some time to fix it :)

Dear Rawalanche, thx for the lesson, I know how to operate with bitmap ;) the question is that using mirrored tiling (and we often use it almost in one axis) it use half size scale, and it's very boring...
I can understand that Ondra choose the same way to have compatibility with max bitmap, I'm just asking if it is better to have compatibility or to have a good/logical/easy way to work with. Maybe we can leave the world better as we found ;D

PS: about your "lesson", don't be afraid for may joke ;)
My Ducati or a render with Corona.....mmm, hard question!

2015-06-05, 10:45:40
Reply #2

Ludvik Koutny

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4. using mirrored instead of repeated tiling works wrong as max bitmap: it use half size scale; can Corona work better than max in this? ;)

It should be this way to make conversion from Max Bitmap to CoronaBitmap easier, and also to make easier to support 3ds Max Bitmap directly in the future. It's not obvious but mirror is actually not bitmap transformation but rather tiling modes. There are 3 tiling modes: No Tiling, Normal Tiling and Mirrored tiling.

To simply flip map horizontally or vertically, you can simply set scale to negative value. So to flip the map horizontally, just set U scale to -1. Works for both 3ds Max Bitmap and CoronaBitmap, but in CoronaBitmap it may still be a little buggy, so give us some time to fix it :)

Dear Rawalanche, thx for the lesson, I know how to operate with bitmap ;) the question is that using mirrored tiling (and we often use it almost in one axis) it use half size scale, and it's very boring...
I can understand that Ondra choose the same way to have compatibility with max bitmap, I'm just asking if it is better to have compatibility or to have a good/logical/easy way to work with. Maybe we can leave the world better as we found ;D

PS: about your "lesson", don't be afraid for may joke ;)

Flipping map by entering negative value in scale box is as easy as clicking checkbox. It's just one step you have to do. If we improved the mirrored tiling mode in CoronaBitmap, we would make two things significantly harder:

1, Converting bitmaps to CoronaBitmaps (otherwise you would have to convert them by hand)

2, Future native support of 3ds Max Bitmap (3dsMax bitmaps will be internally converted to CoronaBitmaps on each render)

If you know how to use 3ds Max bitmap, then you already know how you flip your map easily. There is a difference between flipping and mirroring.

So to answer your question - it is better to have compatibility with 3ds Max bitmap ;)

2015-06-05, 11:06:44
Reply #3

Alessandro

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Flipping map by entering negative value in scale box is as easy as clicking checkbox. It's just one step you have to do. If we improved the mirrored tiling mode in CoronaBitmap, we would make two things significantly harder:

1, Converting bitmaps to CoronaBitmaps (otherwise you would have to convert them by hand)

2, Future native support of 3ds Max Bitmap (3dsMax bitmaps will be internally converted to CoronaBitmaps on each render)

If you know how to use 3ds Max bitmap, then you already know how you flip your map easily. There is a difference between flipping and mirroring.

So to answer your question - it is better to have compatibility with 3ds Max bitmap ;)

Now it'my time for a lesson ;)
Entering a negative value in scale you obtain a mirrored image repeated in space. Tiling with mirroring you alternate mirrored and original image repeated in space. Not two way to obtain the same result, simply two different result.
But maybe there was just an understatement between you and me.

Btw, the second point you've wrote gives a good definitely answer to this question ;)

Thx for your support,
Ale
My Ducati or a render with Corona.....mmm, hard question!

2015-06-05, 12:14:30
Reply #4

Ludvik Koutny

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Flipping map by entering negative value in scale box is as easy as clicking checkbox. It's just one step you have to do. If we improved the mirrored tiling mode in CoronaBitmap, we would make two things significantly harder:

1, Converting bitmaps to CoronaBitmaps (otherwise you would have to convert them by hand)

2, Future native support of 3ds Max Bitmap (3dsMax bitmaps will be internally converted to CoronaBitmaps on each render)

If you know how to use 3ds Max bitmap, then you already know how you flip your map easily. There is a difference between flipping and mirroring.

So to answer your question - it is better to have compatibility with 3ds Max bitmap ;)

Now it'my time for a lesson ;)
Entering a negative value in scale you obtain a mirrored image repeated in space. Tiling with mirroring you alternate mirrored and original image repeated in space. Not two way to obtain the same result, simply two different result.
But maybe there was just an understatement between you and me.

Btw, the second point you've wrote gives a good definitely answer to this question ;)

Thx for your support,
Ale

Well of course. If you want to mirror tile image, you use mirror, if you want to flip image, you use negative scale :)Simple as that. If you need to mirror tile image, but not have it subdivided to two in center of the UV space, then you basically want to flip it. If you need it mirror tiled, so that it tiles multiple times, then you do not need to care if it's subdivided to two in the preview or not, because you will have it tiling multiple times on the object anyway, so you will actually have better preview in material editor. You will see how the tiles look touching each other.

If you show me practical logical case, where it is good to have mirror tiling enabled, but not seeing that it is mirror tiling in the material editor preview, then i will admit i was wrong.

2015-06-05, 14:38:49
Reply #5

Alessandro

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If you show me practical logical case, where it is good to have mirror tiling enabled, but not seeing that it is mirror tiling in the material editor preview, then i will admit i was wrong.

Rawalanche, my problem is not to see something special in preview. My problem is this: if I have a wood picture of a specific wood size (real world) ad I want to repeat it in a surface mirroring it during repeating in a 3d model, I must indicate double size to have the real scale. And that's all folks. I find a little absurd to use correct real size if I simply tile the map and to must multiply for two the size if I mirror tile it.
In attach a picture to explain the problem, simply selecting mirror tile in U axis the bitmap scale change. That's wrong in my mind. But maybe it's me.

My Ducati or a render with Corona.....mmm, hard question!

2015-06-05, 16:19:21
Reply #6

romullus

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In attach a picture to explain the problem, simply selecting mirror tile in U axis the bitmap scale change. That's wrong in my mind. But maybe it's me.

I'm with you on that. The amount of tiling should not depent on chosen tiling mode. It feels wrong and misleading. But i believe that it's just a bug.
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2015-06-05, 16:37:37
Reply #7

PROH

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.. but then it's a bug that's been there forever - and most likely will stay. So as already said, Corona Bitmap has to adapt this "wrong" behavior for conversion reasons. BUT, as suggested, it would be extremely nice to have a checkbox to select correct behavior (correct scale) - when used for new Corona materials.

2015-06-05, 16:51:46
Reply #8

romullus

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OMF... i didn't know that max's bitmap behaves like that. Oh well, i withdraw my support to Alessandro :/
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2015-06-05, 17:01:52
Reply #9

Alessandro

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OMF... i didn't know that max's bitmap behaves like that. Oh well, i withdraw my support to Alessandro :/
Too late. ;P

Btw, i know it's max way to treat tiling, I just ask to be better than max. But, considering that corona bitmap will be integrated (so we will use max bitmap and in render time corona will do the rest) there are no reasons to work differently from max.
What about to give an end to this discussion?! ;) Thx all.
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2015-06-05, 18:00:22
Reply #10

Juraj

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Yeah I was forever annoyed by this idiotic behaviour. Esp, since it doesn't do that in viewport (at least in my case...I stopped to use mirror at all).

Tough choice though: Do things right, or support 100perc. 3dsMax's legacy way ?
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2015-06-05, 19:02:34
Reply #11

maru

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In this case I would say support legacy crap for the sake of proper scene conversion.

2015-06-06, 15:34:37
Reply #12

Ondra

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In this case I would say support legacy crap for the sake of proper scene conversion.
automatic scene convertor can easily handle going from "wrong" to "right". Problem is that userbase is split 50:50 on "I want it exactly the same" and "I want it "correct""
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2015-06-06, 17:32:44
Reply #13

antanas

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 Well why not do both of these modes, with some checker like "use 3ds max\legacy mapping method" which would be on by default and could be set to off\correct mode if user knows what he's doing and why he needs that ?
 Plus one thought about automatic handling of all 3ds max bitmaps as corona bitmaps by default which was mentioned above - that option imo needs some sort of disable function in corona's render setup due to a potential memory consumption growth which comes with it I think at least for the sake of compatibility with older heavy scenes and those users which work with small ram amounts but need to use some large quantity of hi rez textures. Speed increase is of course a very good thing but it is good as long as a render can render and not crash due to a running out of ram))

2015-06-06, 18:52:43
Reply #14

Ludvik Koutny

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I still do not get it. How often do you user mirror tiling? I mean really mirror tiling, not just flipping image vertically or horizontally, because you can already do that using negative scale. If you really use mirror tiling, not just flip, meaning your texture actually mirror tiles on the object, then it tiles in the first place, so you really don't need to care how many tiles you'll see, because it will depend on object's mapping anyway.

Does something like this, that one uses like once every two months, and can be fixed in less than a two seconds by setting two values to 0.5 instead of 1, really need another checkbox?