topic Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg in 3ds Max Modeling Forum

Possible to uvw map a PIECE of a bitmap and then tile that region on a polygon?

Anonymous — Sat, 18 Aug 2018 17:41:42 GMT

I want to be able to have a few tillable textures on a bitmap then pick map say the top corner of that to a poly and then tile it so it fills the poly so I can use less bitmaps in a 3D game.

Been searching and trying to see if this is possible, no luck so far 😞

Hoping I am missing something simple.

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sat, 18 Aug 2018 18:07:58 GMT

You can tile the texture with the UVs or with the bitmap settings

Bitmap settings, quite straightforward, in the bitmap properties

UVs, it can give more flexibility

https://www.youtube.com/watch?v=ZgAJFOe_92A

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sat, 18 Aug 2018 18:59:54 GMT

This looks like it's for an an entire bitmap, I am looking to be able to choose a piece of a bitmap by uvwmaping and then be able to tile only that piece, and not the whole bitmap.

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sat, 18 Aug 2018 19:28:21 GMT

BItmap settings first for tile and offsetok, now I understand thanks a ton!!

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sat, 18 Aug 2018 19:37:28 GMT

ok maybe I am missing something but this didn't work when then going to uv unwrap, it is not using the material, but just the original bitmap again please let me know if I am missing a step or doing it wrong 😞

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

loganfoster — Sat, 18 Aug 2018 21:28:37 GMT

Atlases are a great option to use for more memory efficiency but they do come at a bit of a draw back in that hey can be a bit tougher to work with because they limit how you work. In your case you will HAVE to use an Unwrap UVW modifier to explicitly map UVW coordinates from your faces to specific areas on your 2x2 bitmp atlas. Now where the "limiting" portion comes into play is that with an atlas you cannot increase the UVW coordinates to make your bitmap tile more (because your Atlas has other bitmap data on it as well that will repeat or show), so to work around this you will need to add more edges (preferrably loops and/or rings) to create more faces that you can generate UV data for and arrange as needed to get the look you want.

Also remember that while using the "tiling" options on the map channel will give a result that tiles more in the 3DS Max viewport, this is not data that will be exported and display the same way when you move the data to a 3D game engine as the original poster wanted. This is because the "tiling" options in map channel work more alike scaling on the bitmap and do not actually affect the UV coordinate data that a game engine looks at. As such if you want to make a bitmap repeat more on a specific sets of polygons, and have this show up in a game engine, then the best solution is going to be to adjust the UV coordinates either through the Unwrap UVW modifier or through the UV Map modifier (though the UV Map modifier method will require you to push a selection up the stack and then resize the mapping gizmo).

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

loganfoster — Sat, 18 Aug 2018 21:32:10 GMT

Also be very careful when using Multi/Sub-0bject materials if your intention is to go to a game engine. What happens when you use these is that the game engine needs to make a copy of your model for every material applied to it (Multi/Sub-Object materials have multiple materials) and then visibly hide the faces for what needs to display. This can cause additional polygons, but more importantly additional draw calls. Your idea of an Atlas bitmap is the right way to go, but it should preferably go onto the entire mesh node.

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sat, 18 Aug 2018 21:41:12 GMT

You can crop the bitmap as you want with the bitmap crop editor included in the birmap map.

Check the section cropping/placement of the bitmap map menu.

You can edit the crop by numbers or open the "view image" that will allow you to crop visually, that will update the numeric values. Notice you need to tick "apply"

You can create as many bitmap maps as you want for different crops in materials but using always the same texture.

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sun, 19 Aug 2018 00:01:55 GMT

@loganfoster wrote:
Also be very careful when using Multi/Sub-0bject materials if your intention is to go to a game engine. What happens when you use these is that the game engine needs to make a copy of your model for every material applied to it (Multi/Sub-Object materials have multiple materials) and then visibly hide the faces for what needs to display. This can cause additional polygons, but more importantly additional draw calls. Your idea of an Atlas bitmap is the right way to go, but it should preferably go onto the entire mesh node.

oh wow I am using multi sub objects everywhere! How else would I get different materials on different poly groups?

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sun, 19 Aug 2018 00:03:32 GMT

@Anonymous wrote:
You can crop the bitmap as you want with the bitmap crop editor included in the birmap map.
Check the section cropping/placement of the bitmap map menu.
You can edit the crop by numbers or open the "view image" that will allow you to crop visually, that will update the numeric values. Notice you need to tick "apply"
You can create as many bitmap maps as you want for different crops in materials but using always the same texture.

Thanks a ton for this info, another thing arose out of this the saved .max file doesn't seem to import with the mappings into unity, any trick to getting the mappings to stick for game engines?

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sun, 19 Aug 2018 00:12:03 GMT

You only can export very basic materials with FBX (no procedural, composite materials, odd bitmap map settings etc)

It was like that the last time I used Unity a few months ago, not sure if it has changed.

You could bake the material in Max but that would mean you would lose the advantage of a single texture for multiple uses.

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sun, 19 Aug 2018 14:23:35 GMT

Can you tell me what the alternative would be to using multi sub objects if they are bad I am using them everywhere!

How do I get different materials to different poly groups without that?

Re: Possible to uvw map a PIECE of a bitmap and then tile that region on a polyg

Anonymous — Sun, 19 Aug 2018 14:30:40 GMT

If by multi/sub-object you mean sections of an object defined by a material ID that accept multiple materials, they are fully compatible with FBX and can be exported to Unity without problems. They are used heavily in FBX.

What is not compatible are procedural maps, special materials or blendings or odd settings.