Another DPI question... But regarding textures for 3d

Started by TheBadger, January 08, 2016, 01:45:32 PM

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TheBadger

So generally is it the practice to set textures for 3D models to the same DPI as for web viewing?.. 72dpi?
as opposed to 300 dpi for printing.

We have had some useful threads here about dpi for traditional stuff, but I need to know how people set it for making textures for models. For example I am making a 4k texture set right now. How should I set the dpi? As with printing, is there a pro standard vs. a soccer mom standard? I mean for example, I could make whatever I wanted of course, but if I was making something that was going to a studio for a film, what would I use? If that helps to clarify what I am after.

thanks
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WAS

#1
Good point to bring up...

Images on the web are measured in pixels. Viewports on the web, all CSS, etc, everything is by Pixel. Even when setting a size in EM, EX, REM, it's converted to pixel. Yet many people go through the trouble of setting their images to 72 dots per inch ( DPI ). The process of sizing images for the web is often misunderstood.

Sorry, I'm a Web Developer. xD

WAS

#2
To actually help with the question:

4K textures I just looked at in Fallout 4, and Witcher 3 are between 72 - 300 DPI, I guess it depends on where it's being viewed from.

Edit; yeah it looks like it depends on viewing. The textures for the tops of buildings are at 72 DPI, and the textures for the ground floor (where you can walk right up to the wall) are at 300.

TheBadger



I understand that models in games and for film are treated different (game models need to be low polly and low MB). But How does dpi effect image quality between the two, if at all.
And, If the point is highest visual quality in terms of resolution, then how does DPI effect it if at all? I am guessing that it should be 72. But I would really like to know if there can be any difference or if its possible for anyone to see a difference if there is one.

I do understand what to do with dpi if I want to print the render, but I am not clear on DPIs relevance for anything before that. The simple fact is that I have to choose some number to start the file, so I just want to understand it better.

QuoteI guess it depends on where it's being viewed from

Do you mean how far away, or on what medium?
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Tangled-Universe

#4
How is DPI relevant if neither of the pixels ever end up on paper?

As far as I know pretty much all software ignores DPI info if it's been shown on screen.
As soon as you start a print dialogue or are about to send it off for printing, only then do you worry about DPI.

For texturing your 3d model it also doesn't matter as far as I know.
You have a 4k texture and it is assigned to a bunch of faces of your model and the software doesn't care if these faces are 1 meter or 1 centimeter or your textures 72dpi or 300dpi.

TheBadger

QuoteEdit; yeah it looks like it depends on viewing. The textures for the tops of buildings are at 72 DPI, and the textures for the ground floor (where you can walk right up to the wall) are at 300.
« Last Edit: Today at 02:09:03 PM by WASasquatch »

Ok, that does help to make it more understandable.

But now I just need to know (assuming that the fallout models are examples of standard practice) if 300 is also the standard for models intended only for film and printing.

I assume that there can be no reason to make a higher DPI than 300 for a model when printing, if printing at 300. But there could be some crazy fact I don't know about that will confuse the hell out of me... That would be normal  ;D Based on what you posted, I imagine that you can set it lower if the model is in the background as with your roof and door example.

And also if when rendering and transferring image to film (literally transferring to film) if there is any difference for DPI. I would now guess no, but would like to know for sure.
It has been eaten.

TheBadger

#6
QuoteAs far as I know pretty much all software ignores DPI info if it's been shown on screen.
As soon as you start a print dialogue or are about to send it off for printing, only then do you worry about DPI.

That makes sense too. But you still need to choose some number when creating a file. So if what you wrote is the correct info, then the number should be 72, just for on screen viewing while creating the texture? And then it does not mater again until printing?

But then why the difference for the fall out models? Assuming these are the models form the game... It maters because if those are pro models, then making any of them 300 DPI, will add File size, a pro would avoid that if they could, I am just guessing. SO now I am confused ;D
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Upon Infinity

This is a question that has absolutely no relevance. 4K textures mean just that - the texture image is 4k x 4k.  Dpi doesn't even factor into the equation, you could set it at whatever you want and it would change nothing at all.  What does matter is how many total pixels and how close it will be viewed.  When I'm designing 3D objects, I take the final render into account and how much approximate pixels will be displayed in the final render.  Of course, you must consider that that 4K is very likely being divided among several sides of that object.

Tangled-Universe

Changing a 72dpi image to a 300dpi images does not add to the file size. It's just a scaling factor telling how many 'dots' (pixels) an inch should contain.

DPI is irrespective of pixels, meaning that changing dpi does not remove/add pixels.

Upon Infinity

Also, what monitor since 1998 is displaying at 72 dpi?

Tangled-Universe

The guys who made those fallout models probably did it like that because:

1) they downloaded a texture from google search which was set to 300dpi by a guy who didn't know what he was doing and used that file by itself or as a base
2) they didn't know themselves what they were doing

:D

TheBadger

QuoteChanging a 72dpi image to a 300dpi images does not add to the file size.

OK guys, Thanks, I am clear now. Started thinking about it as I was working and forgot/ignored a basic and that made a bunch of questions based on the wrong starting place.

QuoteAlso, what monitor since 1998 is displaying at 72 dpi?
I was thinking about web. I thought that images for viewing on web needed to be 72? I was conflating I think, all the different things and then applying them in the wrong place on top.
It has been eaten.

WAS

Quote from: Tangled-Universe on January 08, 2016, 03:38:42 PM
The guys who made those fallout models probably did it like that because:

1) they downloaded a texture from google search which was set to 300dpi by a guy who didn't know what he was doing and used that file by itself or as a base
2) they didn't know themselves what they were doing

:D

It seems pretty uniform, actually. And I doubt any textures are from Google...

For example, decals are all 72 dpi for LOD, yet again, for wall decals you can walk up to 300dpi.

This may have to do with other things, for example projectors, virtual reality, directx 12, who knows.

Quote from: TheBadger on January 08, 2016, 03:45:51 PM
I was thinking about web. I thought that images for viewing on web needed to be 72? I was conflating I think, all the different things and then applying them in the wrong place on top.

Browsers all view by the pixel, which allows you to upscale/downscale on the fly.

TheBadger

QuoteThis may have to do with other things, for example projectors, virtual reality, directx 12, who knows.

Thinking like that is what got me really twisted up in the first place.   ;D
It has been eaten.

Tangled-Universe

They use Google, really, they do.

"Anything that works"