How do you know how large or small to make your textures?

[City Builder]

Hello,
Is there a set in stone rule on how large or small to make your textures?

Let's take an example:  Wall one in 3dsmax is 30 meters wide and 90 meters tall (I guess that means in U.S. terms it's 90 feet wide by 180 feet tall), on this wall I wish to place a texture that Im creating in paintshop pro so that it doesn't tile (it has some grunge spots that would look bad tiled as well as some sinage) so how do I know what size in pixels to make the texture in paintshop pro?

Thanks,

[cogeo]

I have some experience with gmax on this, not 3DSmax as I only have an evaluation version which is about to expire soon. However I do think that this applies to some degree to 3DSmax too:
- One criterion is the resolution. I think best results are achieved by using a resolution in the range 7-14 pixels per meter. And of course I'm not talking about the "Resolution" info in the image file (this is only useful for printing, and irrelevant for BAT) but the resolution of the texture relative to the gmax object. For example, if you want the resolution to be 10 pixels per meter, your 30x90m wall would need a texture 300x900 pixels big (it is advisable that you keep proportions and not stretch your texture). Always make sure that the resolution you are using lies within the above range. If it's lower you may get pixelation and/or aliasing effects; if higher than 20 pix/m (esp if much higher) blurring (due to excessive resizing/shrinking) make take place, resulting in loss of detail.
- Also set the Blur parameter in the material editor to 0.0 (default 1.0), otherwise some blurring takes place and details may be lost!
- Another criterion is realism. Beware of the size of what's depicted on the texture, these must be realistic. Eg don't apply a texture with details like stucco ripples or splotches that would normally represent a 1 sq meter large area, on a 20x20m large wall, the effect would be funny. You could make such details 2-5 (or even more) times larger than in reality, if you want them visible in zoom levels 5 and 4 - realism won't suffer much - but don't make them way too oversized.
- If you are using ready-made texturtes, again make sure that the resolution you are using lies within the 7-14 pix/m range. If it's less than 6 or more than 20 (not necessarily strictly-speaking) either choose another texture or scale the image yourself. In Paintshop (PSP) resize (shrink) the image to the correct resolution and then select Effects/Sharpen (shrinking causes sort of blurring). The quality of resizing in PSP is way better than that of the BAT renderer, so better resize the texture yourself and don't let BAT do it for you!
- Make sure that your texture is not stretched, you need to maintain proportions. It might be preferable to change the U and V parameters (in the material dialog and/or the UVW map modifier) rather than crop the image in PSP, as the same texture file might be used in more than one materials, and therefore changing the texture for all these materials will be easier. I use some test-textures, like the ones shown below to check if my textures are applied correctly (tiling/cropping and/or offsets); then I just change the texture file to the correct one.




Below is a closeup of my last BAT (done, but not yet released).



As you can see, details on the walls are visible (this is zoom level 5). These are indeed much oversized (compared to reality), but don't look bad though (I would rather say they are just OK). Making them smaller, first some detail would be lost, and second they would be barely and not easily visible, while at any zoom level other than 5 the texture would just look as a solid/flat colour. I think this is the way to go.

[RebaLynnTS]

cogeo, thank you for this information.

[City Builder]

Thanks for taking the time to help out, it is appreciated.

Let me see if I've got this...
1. Whatever size the dimmensions of my wall, Im going to times it by 10 to get my image size in photoshop.  So if I have a wall that is simply 100m x 100m, then my image in photoshop should be about 1000x1000 pixels. Thus giving me 10 pixels per meter.
2. Adjust the blur factor in material editor to be 0.00 instead of the default 1.0
3. Don't over exagerate the textured parts of the texture.

Basically create a texture for each object, wall, etc that is important enough to warrant one.  I see little point in creating a texture for a window frame that might end up being the size of a quarter the size of a pencil tip eraser when viewed at the closest zoom level.  And lastly try to keep whatever I put on the texture in proportion to the overall size of the texture, so in the case of a walls texture with some graffiti I certainly wouldn't want to use text that is a 72 point font size.

Okay, thanks i think the 10 pixels per meter should help me to get better textures on my models.  I've been suffereing from creating textures that are like stucco where the ripplies are right for a 1:1 size but get completely lost when the image is shrunk or enlarged in 3dsmax.

[RebaLynnTS]

I have been using 46 pixels permeter, but after giving it some thought, the 10/pix would work out a lot better.

[cogeo]

Forgot to mention, these walls are using textures of 15 pixels/meter resolution.
Using a resolution in the range 7-20 pixels delivers good results, with those around 10 pix/m looking more "crisp", and those around 20 somewhat "softened".
Most often I'm making my textures ca 12 pix/m.

[MAS71]

What a nice question post City Builder and great answers by big BATer !!
This is a thing that I want to do know always.

Thank you City Builder for this post and some great anwering all !! 

-Mas'71

[manchou]

Hello !
I'm agree with Cogeo about the resolution of a texture  !
To do a good texture, there is other criterions for me:
-The resolution and the realism is ok, Cogeo have allready said that !
-But to have a realistic texture, it's necessary to observ the nature, for eg: if you do an old industrial dock ( as here  ) it's necessary to know, the old building get older ! That why you make older your old BAT, to do that, you make yours textures with leaks, mosses, mushrooms, etc... It's necessary to choose the good color of the texture, not too agressive, si not the render in the game will be not good     With the good color, you do a good texture!

All of my textures are different, and each of them have lot of details !

To do a texture key to the form of a BAT, i have a technique :

Here is the render of a part of my odl dock



And here the front view:



i show you haw i do the texture of the wall bihind piles.
i become to do an impression écran système in frensh and i create a new image with GIMP or PhotoShop, next "Ctrl-V" to past the impression



I select the contour of the wall (be precise), as well :



Next Ctrl-X and delete the calque, next Ctrl-V to past the selection:





Clic on "image", "ajuster le canevas aux calques"



The result


I open my base texture:



Copie this and past on the future texture:



Look the size of the first calc (view of gmax), memorize the size:



Right clic on the base texture calc (in the calc's window) and clic on "Echelle et taille du calque"



And write the size tou have momorize





The result:



Create a new calc



and select the part under the base texture (or the part gmax view, you see)



next, select the "replenishment tool"



and clic on the selection part



put the opacity at 20%:



and rignt clic on the third calc (in the calc's window) and clic on "Alpha vers sélection" :



Clic on the second calc (the base texture) and resize the calc to have the size of the image !

Next that you need to have a tool, you can found here
Clic on "Script-fu" and "Enhance" next "Smart remove selection..." Beware to select the second calc



And clic on "Valider" and what few time



The result :



You can delete the third calc, and now select the new part of the second calc! And clic on "Couleur" and "Colorier"



You have this window, i modify parameters of the window to have a junction between the first part and the second part of the second calc.



And clic on "Valider"



Afteer that, i found on the net a texture about a group of mussel, and put this on my texture and i play with the opacity to have this effect and the final render of my texture 




Now you know how i do my textures  i hope this tutorial can help some BATers 

A+