3d Worn Down Glass Floor Material Needed

Talbot

Hi everyone,
I'm looking for some help on making a material for a worn down glass floor. I would like to make it look like many people have walked over it. I have tried to find pictures of what I'm looking for but at the moment I have not come across any. I will keep looking for some references to give people a better idea of what I'm looking for.

Also I don't really want someone to just give me a file. I would like a link to a detailed tutorial(s) or someone to write detailed steps on how to do it. I just would like to have the knowledge of how to make it instead of just applying something that is already made.

Thanks.

Eric Chadwick

Flickr: "Glass Floor" serves up many many more like this.

Eric Chadwick

A simple way to repro this would be to make a bitmap of 1-pixel scratches, sneaker smears, scuffs, etc. and use that as a mask for a blurred version of what's behind the glass.

Talbot

Umm I'm going to need a little bit more information on how to do this. Perhaps you could send me a link to a tutorial that explains how to take an image like this into a texture.

I'm sorry I just don't have the knowledge needed to do it with this image.

Tumerboy

you don't use the image he posted. Except as referrence. You use a 1 px brush, and draw a bunch of scratches (black & white) and use that painted texture as a mask for a blurred version of what's behind the glass. (Don't ask me how to do that last part, just repeating Eric. Eric, explain that last part :P )

Kawe

What are you making this in?
Can you make normal glass? Do you know how normal glass works?

I'm very sure you won't be able to find any tutorials. So if you really want to do this you better start trying to think about the problem yourself. What makes scratched glass different from normal glass? In normal glass what matters most is transparency and reflections so... how did both of these change?

In the above image the really badly scratched parts don't seem "transparent" anymore but they are still letting light through but it's all jumbled and produces really bright white lights. The less scratched areas are still transparent but it gets more blurry cause light isn't passing through as straight as before... tbh I don't think there's that much blur.

Then in this image there's multi-layered glass so they produce mirror images off each others too. Very apparent in the upper area of the image.

Also note that the scratched areas would reflect light differently since they have a different angle.

So the question is...what part of this are you trying to reproduce? Everything? I assume you're trying to get this into a game engine, right?

Does it support reflections?

Easiest way to fake this is just to somehow map those bright scratches onto normal glass and make them shine up depending on the camera angle as well as what's behind the glass.

Eric Chadwick

Blurred version would depend on the engine & toolset. If it was a cubemap or bitmap behind the glass, then simply a lower mip of that. If it was geometry, then a low-res render from the same angle.

Talbot

So here is the scene I'm applying the texture to.



I'm not putting this into a game but at the same time I'm making it so it could be. I was the glass to be semi-transparent and be blurred to show a worn down look. I also want their to be scratches. I don't want to render what's behind the glass and make a mask because I would like it to look good from all angles.

I hope this gives you enough information for what I'm looking for.

I just bought a tablet today so I think it will be fun to make the scratches.

Thanks.

Eric Chadwick

So then you could use the scratches in the opacity map (white scratches on gray), and make the diffuse be mottled greenish-white (or whatever color you want the glass to be).

Make sure you find good reference though, or it will surely look like crap. If you don't have a good idea of what real glass should look like, you won't be able to repro it well at all.

Talbot

Ok thanks for help I have one question left. And it sounds easy but I don't know how to make realistic scratches in Photoshop. I have made 1px brush strokes with a tablet but there is no fade on the ends. I just got my tablet today so I don't know how to add pressure variation to brushes. I think this would help make the scratches look better so if you could tell me how to do this that would be great. Thanks!

Rob Galanakis

Good glass is one of the more difficult surfaces you can make, because it is 90% shader and material and has so little to do with actual texture or detailed maps. You are obviously at the start of your learning journey, why throw such a wrench as scratched glass into the mix? Don't use glass, use another material that will be more straightforward to create. Creating this glass is going to be a giant headache, for a crappy result, and you are going to learn very little because all the concepts behind glass require foundations you have yet to learn. Start with something simpler, and once you can create other believable surfaces, then move on to scratched glass.

Talbot

Well could you take a look at my scene and a suggestion on what I should replace the glass with? Thanks.

Tumerboy

standard, slotted, metal grating.

Eric Chadwick

For the fading strokes, read up on the options in the Brushes palette in Photoshop.

sir-knight

I would go with tummerboy's solution, for the location, a metal grate is much more believable as access paneling.

Eric Chadwick

Yeah to be clear, I'm not advocating the glass either, the grates are probably a better idea. Why would they have glass there? And why would it be scratched?

As Adam puts it in his article, the story is important. Right now I don't see your environment's story.
http://www.adambromell.com/articles/article3.html

Talbot

Well I wanted it to be more of a futuristic but worn down feeling...

So to make a grate do I basically make a plane and remove faces. Then add a bumpmap to give a more 3d feel?

Eric Chadwick

No, you'll probably want to use opacity for the holes. Just make the mesh a single quad, and make a high-res mesh to get the normal map and opacity map.

sir-knight

Talbot wrote: »

Well I wanted it to be more of a futuristic but worn down feeling...

I was thinking that too, but you need some contrast with all the 'smoother' surfaces you have there, a grate would add some nice real world texture to the scene. There's plenty of other things that you can add to make it futuristic. Just think about the aliens movies or the original star trek movies, those sets were futuristic but very functional, gritty and cold, not many glass walls or floors in those settings. Reference your favorite movies and build from there.

Also think about where that panel is if it were glass, it's sort of out of any sort of high traffic area, so why would there be scratches on it? I'm not much of an environment modeler (or 3d artist at all quite yet) but I think you need to consider the ergonomics of the scene, does putting that piece of glass there suit a function to the people that live in that world and does the look/texture you are going for suit it's use?

Tumerboy

ya, the geo you have in your scene is already fine, just do as Eric says, make a high poly, tilable geo, and render that down to a tilable texture you can apply to the whole strip.

As for the glass, the big question here is, Why?! Even in the future, WHY would they want this panel to be glass? What advantages would it actually give, over a metal grate (or something else?). As far as I can see, it would overall be a bigger disadvantage than advantage. It's more likely to break, it's probably harder to get into (for an access panel, that's bad), and unless that whole slot is filled with a pressurized liquid/gas there's no reason it would need to be air tight but visible. (i.e. it could be covered completely, or could be a grate)

That's not to say you SHOULDN'T do glass, if that's what you really want, but you should always have a reason for doing something like that. As Eric pointed out, there's no story here. If you're going to do glass, you need to come up with a story about WHY it's glass. And that story has to be apparent in your image, not just something you can explain to us. You should never have to explain something in your work like that. If someone has to ask, and you have to stop, and say, "Well, this is glass because. . . " you've already lost.

Talbot

Thanks for the help everyone.

Sir-knight:
You brought up a point about the smooth floor. When I first did a render that is something that I noticed but didn't bother with right then. Do you know why there is the shading in the floor?

Eric:
Sorry I really feel like an idiot but could you be a little bit more specific?

I just want to say thanks to everyone for baring with my lack of skill. I'm not taking a class on this so basically everything I know is either self-taught or you guys teach me. So I'm sorry if I keep asking you to be more specific but really... you guys are the only ones that can help me.

Tumerboy

Talbot, don't worry, we've all been there, so as long as we see you making progress, and not being a sassy bitch, you should do fine :P

The set up he's talking about, you will make a texture, with metal in the RGB channels. You will add an Alpha channel in Photoshop, then you'll fill it with white, and where you want holes (to see through) you'll fill with black.

Hope that makes sense. . .

Eric Chadwick

Well what I really meant is for you to model a high-poly version of the grate, complete with bevels and bumps, and holes where you want them to be. Then when you bake a normal map from it, you can also bake the opacity map.

Normal maps for hard-surface items are usually best baked from geometry, instead of being made wholly in Photoshop.

You should really learn high-poly modeling skills if you want to create normal-mapped environment pieces.

Talbot

Before I really try to understand that last post I need to ask a question that I should have asked a long time ago. What are normal maps? I'm going to google it now but I would still like to here you explain it. Thanks

Also, do you think it would be best to watch some more tutorials for a couple days before I continue this project? I just feel like I bit off more than I could chew and I should catch up and come back to it later.

Eric Chadwick

Naw, the best way to learn is to do.

http://wiki.polycount.net/Normal_Map

Tumerboy

Sorry Eric, I was just simplifying the whole thing. I agree wholeheartedly in baking for normal/opacity. I just wasn't sure if he was confused on that, or on the use of alpha in the first place.

Talbot

Ok thanks. I am sort of seeing what it is. Mainly I recognize that look and style from a lot of games. Before I ask how to make them, I'm would like to know the difference between a normal map and a bump map. I think I can tell the two apart when I look at renders so maybe this question will be answered when you tell me how to make them.

A couple days ago someone recommended XNormal to me. Maybe when you explain how to make normal maps you can include this (that is assuming you know about xNormal).

Thanks.

Talbot

Tumerboy:
I do understand how you were suggesting I should make the grate with the Alpha channels but here is another really easy question that I should know the answer to but I don't. I have heard the term baking a lot whenever I'm cruising through polycount. Does it just mean compile or make? or something completely different? Thanks again!

Eric Chadwick

Sounds like you haven't read that wiki page. Should clear up a lot of questions, and stimulate some more too. In fact I'm curious what questions you come up with after reading it, might help me improve it.

A normal map is a type of bump map. Another kind of bump map is a gray image where the bright parts are bumped out, dark parts are bumped in, this is usually called a height map or an elevation map.

There are many methods for using a height map as a bump map, but normal maps are used the most often in games because they tend to look better than height maps.

Talbot

I'm sorry I did start to read it but it was a lot :P. I'm horrible at reading large amounts like that.

And actually every time I try and explain what I got confused on, I go back to the wiki page and find the answer. :P I really feel like an idiot but I guess it comes with being horrible at understanding large amounts of text like that.

So basically I feel like I understand how bumpmaps are just up and down on the surface and normal maps are up and down but also sort of side to side and angled... now I know why I could never understand it from reading it, because I'm having trouble explaining it my own words. But I think I understand them now.

And now I'm feeling like everytime you tell how to do something I have a question on how to do a part of the original "how to do" :P. I'm just going to continue with my question and not try and reowrd that last sentence. But I need some help with how to make a high poly model of a grate. And I really feel like this is turning into a sort of tutorial in it's self but like I have said before... I'm learning a lot from this and hopefully my next project will go smoother.

Eric Chadwick

It's all cool. You're tackling a bunch of difficult subjects, but they're things that many of us have had to learn ourselves (and are still learning).

High-poly modeling for normal mapping is another big subject. Check out the Environment Modeling section here on the wiki.
http://wiki.polycount.net/CategoryEnvironment

Don't give up though, take it in small doses, keep moving forward. You're going in the right direction.

Eric Chadwick

Oh, and I'm finally getting back to editing the Normal Map page on the wiki, so you might see some sections change a little. More pics, less text, that kind of thing.

Talbot

So how would you go about doing I high poly model of this?

My first thought would to create a box and than extrude all the faces (except the top and bottom) twice and repeat the process on the second extrude until, 2 hours later, I have the size I want and than make it into a sub div. But there has to be an easier way... right?

Talbot

OH and I like how this went from a texturing to a modeling thread...

Tumerboy

So, Eric, in the interest of taking baby steps here, might I suggest Talbot try some basic height & Normal map creation (in Photoshop, xNormal, CrazyBump, and/or Nvidia Filter)?

Once he has a better understanding of the basics of how normal maps work, THEN try the high poly model bake.

I'm going to proceed as if we all agree :P

So, Height based Bump maps are just that, height. Black is low, White is High. Try making a basic height map in Photoshop. Just paint the whole thing medium grey (128, 128, 128 ) and then paint some black and white shapes around. Take that into Max or Maya, apply it to the Bump Channel of your material, put it on an object, and render it, and see how it looks.

Once you see how that works, get xNormal, CrazyBump, or the Nvidia Filter, and use your original height map you made, to generate a normal map. (I highly recommend picking up CrazyBump. It's $100 for a student license I think, but totally worth it.)

See how the maps differ, and then try the same process of applying it to your object and see what it does differently.

Chances are, in your render you won't see a difference. The main difference is in how game engines use them. Bump maps in the engines I've used, mainly showed up where specular highlights were. So edges that would catch spec would show up, and thus, show off your bump map. Normal maps in the engines I've used, have been far better, in that they will catch diffuse light, not just specular highlights. So you can see that detail without having everything be specular.

______________________________________________________


Basic Normals info: Every polygon has a normal. This is an imaginary line that points in the direction the polygon (triangle) faces. It is perpendicular to the face.

If you have two triangles next to each other, with smoothing off, you will see how each face points in a different direction. Smoothing attempts to blur those two normal directions to point the same way, so you don't get a hard seam between the two polygons.

Normal Maps, take that original height map info, and attempt to generate a normal PER PIXEL, rather than per face of the object. That's why you can what looks like a lot more polygonal detail on an object than is actually there.

The term Baking refers mainly to taking one thing (usually a high poly object) and transfering information to another thing (usually a low poly object) So in this instance, Eric was saying to model a high poly grate, then Bake out the normals (to a normal map) and use that on a low poly grate. That way, you'll have a low poly grate, that LOOKS like it's got the detail of the high poly grate.

Talbot

I was sort of working on a bumpmap project on the side before I started this post.



I basically just made the texture map greyscale and applied it as a bump map. The map is very big (1024x1024) but I was really just practicing so I didn't really feel I needed to go back and do it over with a small texture.


Here is the model:



I don't really want to make a high poly crate showing all the bumps.

But I did get the Next Texturing Tutorial from eat3d about a week or two ago. So maybe I should finish that and if I have end up having questions on that I should start a thread with the questions I have when going through it? Then people in my position can have an easy place to find answers instead of in a thread that started out as worndown glass texturing help.

I'll start watching that in the meantime.

sir-knight

mmmm normal maps.... bump maps on steroids...

I've been working on 3d for a while now in my spare time, and I'm still not bothering with normal maps. I figure I still need stronger foundations in texturing, proper topology for good deformation, economic modelling and generally just get faster in my work flow.

Of course... my computer at home is about 6 generations behind and can barely run any sort of normal map game... that has a bit to do with me not getting to them quite yet. :P

Eric Chadwick

Talbot wrote: »

So maybe I should finish that and if I have end up having questions on that I should start a thread with the questions I have when going through it? Then people in my position can have an easy place to find answers instead of in a thread that started out as worndown glass texturing help.

There's already a thread for this...
The ultimate be-all end-all normal mapping thread

Talbot

Eric: how would I go about creating a high poly model of the grate that I inserted a couple posts ago?

Jonathan

Talbot wrote: »

Eric: how would I go about creating a high poly model of the grate that I inserted a couple posts ago?

(1) Model the main shapes, then you "support" the shapes with extra edges (I often selection the ring of edges, use the "Connect" tool in Edge mode in 3DS Max, have the connects on 2, with a spacing between 85-95 depending on the object (not sure how well this description will transfer in text, but I'm too tired this evening to post pictures of it). Either way, what you're doing is just supporting the edges either via extra edge loops (what I prefer) or via chamfering an edge, but this can get messy fast.

(2) Then you can create the low-poly, or modify the original, unsmoothed/sub-divided mesh you worked on earlier, only keeping those edges which give form to the shape.

Then you'd use the "Projection" tool in Max to bake the normals information from the high-poly to the low-poly.

As for bump maps (I think this is an acceptable and terse explanation, someone feel free to correct me if I'm wrong), normal maps replace the normals information of the low-poly, whereas bump maps only perturb the normals of the low-poly. Normal maps hold 3 values, whereas bump maps are only up or down, basically. So normal maps can show forms nicely, bump maps just add subtle surface detail.

Talbot

I made this using the lattice tool on a plane. Then Subdiv it.



I know it isn't the exact grate that I wanted above but I think it would work. What do you think?

Eric Chadwick

The result isn't clean, there are better ways to do this, but this way is really quick. Go here to learn more about subdivision-surface modeling.

Talbot

Thanks! I'm about almost done and will finish it tonight. I ran out of time because I need to go to work. I'll post a render when I'm done.

Kawe

holy hell. that's some badass gif image

Talbot

Yeah tell me about it...

Talbot

Is it just me but selecting the edges for the second chamfer takes a very long time. I am making a larger grate but I mean... I selected edges for like 45 min last night and I don't even have all of them yet. Is there some trick to selecting edges that I'm not aware of?

Eric Chadwick

See the blue icon that has a dotted box and a black ball inside it? If you turn that on, dragging the selection marquee will only select edges completely encompassed by the marquee. The default mode instead selects all edges that cross the marquee.

You can see my dragging the marquee on the right side there. I missed some edges though, became obvious when I chamferred with the sub-division on.

Talbot

haha :P I knew about that but for some reason I didn't think of how much it could help when doing this.

I just realized I didn't chamfer all of the vertical edges to the extrude. So I'm going to restart and make it a little bit small this time.

Tumerboy

You could also just make s amall section of grate, and then clone it around.

Talbot

Yeah that's what I was thinking about doing.. but having a bunch of grates and not just one big one.

Eric Chadwick

Yeah you could make an X, then snap-clone it, that might be easier to manage.