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bonestructure
09-18-2009, 05:00 PM
In general, I'm quite good at making textures. But I have one weakness that I can't seem to conquer. This is, for example, when you have a road oe a lawn, a ground texture. Most of it will be pretty good, but when it gets to the foreground, close to the camera, it seems to always blur of just look like crap. If an object is solo, the textures are fine, but on grounds and walls, this problem occurs. I'm not sure if this occurs because of the average 45 degree angle between the ground/wall and the camera or exactly what causes it. It doesn't seem to matter how high res or sharp the texture map is, it seems to almost pixelate or blur. The problem hasn't been as severe since I switched renders to Vray, but it still occurs. I'm hoping someone here can either explain the problem to me, or provide some kind of solution. I've been able to get by with it because I've worked it down to a point that the average viewer won't really notice it so much. But it dissatisfies me on a personal artistic level. I have a feeling it has something to do with the angle, and certainly, I can resolve it by having the camera at a higher angle in order to have the ground plane further away, but it's not always possible to do that.

It's funny how, the better you get at CG, the pickier you get, the more details concern you. I've never attempted to do photorealism, as I'm an illustrator rather than a photo realist. But I come close, or try to, and little things like this bug me. So now I'll wait until Neil or someone comes along and tells me the problem is quite simple and gives me a solution so simple I'll bang my head on the desk wondering why I didn't figure it out myself lol.

Fumetsu
09-18-2009, 10:58 PM
Heya,

I am guessing that it has something to do with the resolution of your texture map. Have your tried breaking your object down into smaller chunks? That way, your uv's for the foreground part can take much more space to accommodate higher resolution textures.

Also, there is a guide somewhere on this forum which explains how your texture resolution relates to the size of the rendered image, I recommend that you look it up.

I think you might also be able to use tiling textures for things like roads to get away with this problem. I am not sure of this though.

bonestructure
09-19-2009, 04:04 PM
Well, I usually make my texture maps from 1500X1500 to 2000X2000. I can't see going any larger than that, though I have had some 3500 from high res photos.

I did recently break down a ground plane into three sections. It helped a little, but not entirely.

leigh
09-19-2009, 04:17 PM
It would help if you showed an image of this happening, although from your description, and from your post above mentioning what size textures you use, I'd have to say it's a resolution issue. Remember, the pixels of a texture map should never be shown beyond a 1:1 ratio, in other words, never show them in a way that they're essentially zoomed to beyond 100% of their pixels. Just like zooming in 300% in Photoshop, your image begins to appear blurry and soft. Always ensure that your texture maps are large enough to hold up in your shot.

1k and 2k are actually very small sizes for textures.

bonestructure
09-19-2009, 04:45 PM
Well, my render size is usually 900 X 1350. If you look at my last post in the gallery here, THE DRAGONKEEPER'S DAUGHTER, the problem isn't too bad, but you can see that in the front, closest to the camera, the texture does begin to flatten out and break up a little on the ground. It's not so much that anyone but me would notice, as I have gotten better at dealing with the issue, but it still bugs me.

"1k and 2k are actually very small sizes for textures."

When you say that, I assume you're talking about 1000, 2000 in actual pixel size rather than in data size?

I sometimes do try to tile textures, but that method doesn't satify me terribly well in ground textures, such as roadways, dirt, etc. Even if I make the tiles so that they don't repeat any obvious patterns, it still creates too much regularity and not enough fractal deviation. I especially have problems with dirt and with asphalt. Roads, as in city roads, seem to be especially hard to do. I've copped a couple of textures from CGTextures, which is a wonderful resource, but those don't please me overmuch either. I mention that because my current personal project has a road, which is a small part of the foreground, but I want it to look right. I'm not a photo realist, but I do get close, so that bothers me. I also have trouble with curbs and sidewalks but that's purely a texture issue rather than anything else lol. I think I've made a good one for the current project, so we'll see. I'll try to make my road texture larger and see if that helps.

Is there anything in particular I should do for the bump map to improve this problem? More sharpening? More contrast?

leigh
09-19-2009, 11:49 PM
Well, my render size is usually 900 X 1350. If you look at my last post in the gallery here, THE DRAGONKEEPER'S DAUGHTER, the problem isn't too bad, but you can see that in the front, closest to the camera, the texture does begin to flatten out and break up a little on the ground. It's not so much that anyone but me would notice, as I have gotten better at dealing with the issue, but it still bugs me.

I don't see any major resolution issues in that render myself, although it would be interesting to see a larger render of it. If you're generally rendering at 900x1350 (what a strange resolution!), then you should always ensure that any part of a texture showing up within that frame has a resolution that's equal to, or larger than that.


When you say that, I assume you're talking about 1000, 2000 in actual pixel size rather than in data size?

Yep. 1k - 1024x1024 pixels, 2k = 2048x2048 pixels, and so on.

Is there anything in particular I should do for the bump map to improve this problem? More sharpening? More contrast?

Well apart from ensuring your texture map is indeed large enough to hold up when it's rendered, you can use tricks like copying your layer, running High Pass, and then overlaying it on top of the original to sharpen things. But generally, having a good quality texture at a large enough resolution is sufficient to ensure good quality textures in your frame.

rd1010
09-20-2009, 04:55 AM
What kind of texturing are you doing, are you using photos and doing it that way, because that isn't going to produce optimal results, you have to get pretty in depth to make a good up close cg texture which would usually consist of layering displacement maps as well as using color maps and tweaking other aspects of the material(s) to produce the look that you want.

bonestructure
09-20-2009, 01:04 PM
The 900 X 1350 resolution is my normal book cover size.

I do use photos, high res photos, and usually combine several in layers to get the look I want. Most of the photos in my library are at least 2k. I also paint if need be to accomplish whatever it is I want. I'm also wont to use Max to make textures larger if need be. I have a 2500X2500 plane set up to cover the front window, and often use the blend material and Vray to render out new textures, or whatever else I happen to experience, tiling, blend maps, grunge maps whatever might work. It's just something I've been experimenting with for a while, but it gets good results.

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