Texture resolution

[gadzooks]

I want to make a texture of a street with all the lines and pot holes and manholes etc...etc...etc.... But my question is, at what resolution should i make my textures. I have made textures before that look ok from a distance, but soon as you get near them they fall apart become very pixalated. Is it based on the final output size of your image. Example
if you were going to render out a 200 dpi image say 2000x1200 would you use textures that were say 72 dpi at 1024x768? Does this make sense? Really all i want is to know at what resolution i should make my textures so that they wont be so pixalated. gadzooks

[J_Bug]

To do it the way you want to it will really depend on how close the camera comes to the road as well as the final output resolution. For the output you've specified I'd say you're going to need a much larger map than 1024x768.

Try making a little more complicated material that utilizes alpha channels and masks. I'd make the manhole covers geometry and use a set of tilable maps offset and rotated within a noise for the asphalt. If you think about it, the lines on the road don't need to be extremely high res because they will mostly deal with horizontal and vertical lines, which will become blurred but you shouldn't see the pixels.

Hope this helps you get started. You'll just have to play with it allot.

Why 200dpi if you don't mind me asking? Is this a still, for print, or an animation?

--Jon

[J_Bug]

Here is a link to a nice high res street map from Absolute Textures and it's one of the free examples maps they provide to sell the products.

http://www.absolutetextures.com/road026.jpg

--Jon

[gadzooks]

Thanks J_Bug for the info. I have really never been clear on how to size the texture map accordingly. If it looks good from a distance, but then you come closer to the map it starts to break down, gets pixalated. Now i know the old saying if its not close to camera it doesnt have to be perfect.
I just didnt know if thier was a starting point. (example) you know your end image size will be 1024 x 768 so all texture sizes should be no bigger than say 512 x 512 at 72 dpi. I acn show you what im talking about but i would have to e-mail you an image i cant post to this forum. The image will be portfoilo.

[J_Bug]

It all depends, I don't think there can be any hard formula. Preproduction is the key but you can always wing it and just say...

no that texture needs to be higher now that I see it rendered so you should make/ find/ buy a new one. A digital camera and Photoshop would be handy in this case.

--Jon

[Biohazard]

It might be quite complicated to compute but the easy way is to consider the texel/pixel ratio:
How large will be the road at max compared to your image output size ?
The basis would be (if your shader/textures are nice) a ratio around 1.

At the opposite, it's the same with oversized images that your renderer take hours to downsample and filter.

I follow J_Bug 100% with mixing textures and using procedurals to break the tile effect and smooth bitmaps with each others (try 2 bitmaps blended with a procedural noise for example).