Posted by: keystonelemur | November 19, 2008

Major setback…

Nothing is more annoying than going through tech training and computer maintinance than to come up with something on your own computer you can’t fix…

If anyone that reads this can help at all here’s what I’ve gathered on it.

First startup – Blue screen, shuts down, fixed by system repair.
Second go – Black screen with only a mouse cursor. Suspected some form of virus, restore points all wiped outm registry locking me out of editing Software and overwrites whenever I change the shell from :

cmd.exe /k start cmd.exe
to
explorer.exe

Changed it once, restarted, same problem, looked in the registry and it was back.

Right about now the only things I haven’t tried are the Vista recovery disk, a Linux Live cd, and just formatting it (All important data backed up onto an alternate drive much earlier just in case, rather glad I did that now)

If anyone that reads this can help at all leave a comment or something. Thanks.

Posted by: keystonelemur | November 18, 2008

Space Art 101 -Nebulae

Nebulae Tutorial

1. Intro

If you haven’t already you need to check out my earlier tutorial on Star Fields, if anything you can consider this part 2 because so much of nebulae are built upon your star field.

2. Starting Out

Create a new document ( 500 x 500 ) and fill it with black, repeat the steps used in the Star Field tutorial or if you wish to use the same file. I’ll create an action to do this and upload it later.
After you have the Star Field ready you already have a very basic dust nebula. You can stop there but if you want a more detailed nebula keep reading.

3. Onwards!

Duplicate the star field and use Filter >Render >Difference Clouds and hit Ctrl +F at least 10 times or until you get a nice division. On the layers window there is a Circle half black and half white, click on it and select Gradient Map.

4. Some more color

Pick the default gradient composed of Blue Red and Yellow (See pic) and set its mode to Reverse. Tad bit of a wakeup call on that one. Make a new layer above it and use Filter > Render > Clouds and find something you like. Set the mode to Multiply. Merge the layers and hit Ctrl + U and set Saturation to -50.

Render some difference clouds again, 5 clicks should do. Make a new Gradient map and use the Default Orange Yellow Orange (pic) and set the mode to Soft Light. Take the layer below it and set mode to overlay.

Merge all layers, duplicate and use a Gaussian Blur of 3 px and set the mode to either Screen or Color Dodge depending on preference.

5. Optional

Create a gradient map and use whatever gradient with more than one color and try Soft Light, Screen, Color, Linear Dodge, Color Dodge, and Hue. Also play with Color Balance. What I have after tweaking:

We now have a more advanced dust nebula; color tweaking is very much an option, play with different gradient maps and the Hue Saturation tool.

6. Cold hard reality

Now some people might be wondering how in the devil some of the advanced artists can manage to do such unique and far ranging nebulae. The answer is about 5 Hours or more of hard work and using a default brush and painting it.

This may be something I cover later, but only if I get enough comments requesting me to do so, leave a comment or email me at keystonelemur@gmail.com

Posted by: keystonelemur | November 17, 2008

Space Art 101 – Star Fields

Stars tutorial

Previously I have explained how to create realistic planets in photoshop, now it’s time to learn how to make a star-field in ANY version of photoshop with no drawbacks whatsoever.

Shall we?

Starting with Black
I figure since God started with a black canvas why not us, eh? Make a new file of 500 x 500 resolution, any size will do if you feel like experimenting, the effect is the same.
Adding Noise
Take out a brush and… No, I wouldn’t do THAT to you, that’d be inhuman. Check out the Filters menu and go to Noise > Add Noise. Set it to Gaussian and check the monocrome option. Typically you will want anywhere from 25 to 50% noise, it’s a personal preference but for the most part go with 40%.
Brightness / Contrast
There are two ways of thinning out the stars, levels or brightness/contrast. In Brightness and Contrast it’s far quicker, just set the Brightness extremely low and set the Contrast high. Again it’s up to you to decide what you think looks right, for the sake of the tutorial I used -150 +100.

Duplicate the layer and apply a Gaussian Blur (3 px.) Now hit Ctrl + U (Hue / Saturation) and check the box labeled colorize. Go for any color, blue is used here. (250 Hue – 80 Sat – 0 Light). Set the layer mode to screen.

Levels
Time to take down the amount of stars here, merge visible using Ctrl + E. Duplicate the Background layer. Make a new layer and go to Filter > Render > Clouds. Hit Ctrl + F until you get something you like. Now open levels and use the following settings : (70 – 0.43 – 208). Set the layer mode to Multiply, if you like the effect then duplicate and set the mode to color dodge to add some brightness to the remaining stars.
Flare
Now let’s get some larger stars in there to brighten it up a bit. Merge Visible again with Ctrl + E. Make a new layer, fill it with black and go to Filter > Render > Lens Flare. Use the Eliptical (Circle) select tool, holding shift select the center of the Flare and use Filter > Blur > Radial Blur at 100% spin. Hit Ctrl + J and delete the other layer.
Radial Blur

Set the new layers mode to color dodge and transform the flare to be much smaller and liberally use the duplicate and transform function, just remember that larger stars are normally in the already bright areas.

Finished!

You now have a star field to use with your planet, have fun and experiment some with the tutorial, do it over with a different color or try a higher noise percent, feel free to do whatever.

Posted by: keystonelemur | November 14, 2008

Space art 101

In this tutorial you will probably need photoshop Cs3. The tutorial is still possible with lesser versions, but the clone stamp or healing brush must be used to blend the layers instead of the Cs3+ autoblend.

You’ve seen space work before, you couldn’t believe how real it looks and never believed that you could ever make such a thing as that. Wrong. With a copy of photoshop you can easily learn how to make planets, it is merely the mastery that is difficult.

What we’ll be making today

Step 1 – Getting Started

We’re going to begin with how to use NASA images to create a new planet.

Before we get started we’re going to need some images to work with here. Personally my favorite place to find great images to use is the Visible Earth project from NASA. The
best Satellite I’ve found so far is the Terra > MODIS. Download all the images below. Make sure to download the highest resolution image of each, if you want to find some more,
mix and match, even add a few more images from other satellites.

http://visibleearth.nasa.gov/view_rec.php?id=233

http://visibleearth.nasa.gov/view_rec.php?id=241

http://visibleearth.nasa.gov/view_rec.php?id=282

http://visibleearth.nasa.gov/view_rec.php?id=295

http://visibleearth.nasa.gov/view_rec.php?id=1412

http://visibleearth.nasa.gov/view_rec.php?id=1794

http://visibleearth.nasa.gov/view_rec.php?id=1912

http://visibleearth.nasa.gov/view_rec.php?id=1950

http://visibleearth.nasa.gov/view_rec.php?id=1958

http://visibleearth.nasa.gov/view_rec.php?id=2051

Into Photoshop, create a new image with the dimensions of 3000 x 3000 at default DPI. This may seem rather large at first but in all honesty there have been ones
made at 10000 x 10000 resolution or higher by other celestial artists.

Step 2 – Creation

Open each of the images and paste each onto a new layer, feel free to transform the images to get a good size. The beauty of creating planets is that there are almost no rules
against what you can (and most likely will be tempted to) do.

The images from NASA scattered around the page, any ordering or duplication will work, in fact I encourage it, it’s no fun if people copy me.

Select all the layers and go to the Edit menu and click Auto-Blend. Merge the layers. This will take away a majority of the work you have to do here but there’s still some manual
touch-ups that need to be made.

After the Autoblend (saves hours… Miracle tool in my opinion)

Auto Blend is found in the Edit Menu and all layers the effect is to be used on must be selected.

Take out the clone stamp tool and set it to 45% Opacity and 20% Flow and begin to blend some of the rough edges left behind. If you want to feel free to play with the opacity and
flow, water tends to work best with a higher opacity and medium flow while land works best with low flow inland and high on coastlines. This should take roughly 10-15 minutes
depending on the size of the image to get right. A trick to getting the shape and ridged edge of a shoreline is to get shoreline images to start with and clone the edges onto other
areas.

After some help from our friend the clone stamp tool.

Default: Opacity 45% Flow 20%

You now have a completed texture to work with, save this, it can be extremely useful for later (who said anything about starting from scratch every time?)

Step 3 – A Planet emerges

Take out the elliptical marquee and start at one corner holding shift and select down to the opposite corner. Hit Ctrl + j and Ctrl + click the layer. Go to Filter > Distort > Spherize at 100%. Put a black layer behind it and we have ourselves a planet.

After Spherizing the texture.

Found at

Filters Distort Spherize (100%)

A couple quick tweaks before we give it atmosphere. Duplicate the planet layer and go to Filter > Other > High pass and set it to 40. Apply it and set the layer mode to soft light
and merge.

Now expand the canvas size to 3500 x 3500, fill the background layer again to get rid of any lines. Duplicate the layer twice, on the top fill it with black and set the mode to
Screen. On this layer apply an outer and inner glow with the color #c2c1ff with no choke but a high spread. Take the second, fill it with black and use transform and hold shift as
you drag a corner down to about half the original size. apply a blur at 50 and set the opacity to 90%.

Step 4 – Completion, Further reading, and Inspiration

The planet is now completed ready to go. You can stop here if you want, but in Celestial Art the possibilities are endless. Of course I added a couple tweaks to the finished version, more of secrets I keep.

Great inspiration:
http://www.taenaron.deviantart.com
http://www.joejesus.deviantart.com
http://www.baro.deviantart.com
http://www.somnicelestia.deviantart.com
http://www.gucken.deviantart.com

My work:
http://keystonelemur.deviantart.com/gallery/#Space-Art

If you enjoyed this send me what you came up with or at least a comment. Thanks. These tutorials take time to write, I’d be rather disappointed if no one said anything.

Posted by: keystonelemur | November 6, 2008

10 Commandments of Web Design

I. Thou shalt not use Comic Sans

It doesn’t matter what form of justification you can humanly come up with, if you’re not a grade-schooler using every font word has to offer you DO NOT use this. Comic Sans is a font that is far too cartoony and childish for any practical purposes. Period.
II. Thou shalt not design with tables

I don’t know how many sites I’ve visited that have used tables as the primary way to design a layout. Tables can be used for layouts, but the effectiveness is horrid. Tables are used for data, not layouts. CSS Based layouts are overall cleaner, easier to manage, and can be moved and modified infinitely faster than a table site.

III. Thou shalt not use the name of gradients in vain

I’ve seen far too many people use gradients so liberally that the design of their site overall suffers. In some cases I would even debate as to whether or not it can be called a design. It’s going too far if the only images you have on site are gradients, you need white space and even more so you need some actual imagery.

IV. Thou shalt stay the heck away from Publisher

Publisher deserves to be burned for all the horrific things it has let onto the web in forms of school sites and cheap business layouts. Publishers code that it generates is such a garbled mess that almost no one can translate it to english, much less valid html. Publisher sites have a nasty tendency to look cheap because of little to no control and the availible control is horrid.

V. Honor thy w3 and compliance standards

This has to be one of the most important by far. Without standards for the web there would be absolutely no order, we would have firefox only, IE only (Lord forbid…), Safari only, and etc. Imagine what that would do to the commoner looking through some sites. If your little tool or trick doesn’t stay within these standards then chances are it’s a bad idea.

VI. Love thy framework as thyself

Frameworks are a miracle in and of themselves. They save massive ammounts of time and sleep and provide an easier way to do things. Frameworks can speed up development by hours at a time making you more money, getting more hits, the whole deal.

VII. Thou shalt have no IE 6 or below before me

IE6 and below are the WORST NIGHTMARE of almost any designer and coder out there. Why is this? Because of horrid compliance to hte w3 Standards. If I could chose between inheriting Bill Gates fortune and permanetly eradicating IE 6 and below I would go with nuking IE without batting an eye.
VIII. Thou shalt not blindeth thy visitor with flourescent colors

No, Hot Pink does NOT make your site or font stand out. I’ve contracted some form of epilepsy from all the clashing and bright colors some people try and pass off as design. 3 Colors and you’re done, you jam your entire crayola set into your screen and somethings wrong…

IX. Thou shalt not hoggeth my bandwidth with hotlinkething

Image theivery is probably one of the most annoying things out there, this includes site ripping. Why exactly people believe that they can borrow someone elses work then claim it as their own for their own glory is far beyond my comprehension.

X. Thou shalt not covet thy neighbors hosting package.

Or their design, or their code, or anything else of theirs for that matter. Grow up, make your own, quit sitting there bad-mouthing every design that’s better than yours in an attempt to gain some sort of fame. If you want to really get out there there’s only one real way, and that’s hard work. Might as well make hard work a curse word for some of you while I’m at it…

It’s a joke do note. I’m Christian so I’m not blaspheming this… Might go through a couple revisions.

Posted by: keystonelemur | November 6, 2008

CSS Based Design 101

CSS based Design 101
Before you read this you should learn HTML at http://www.w3schools.com and look up some CSS afterwords.

Tables = Data only

Look through most sites today and tell me what you see. A vast majority use a system with a bunch of div tags and *gasps!* no tables! This is called a CSS design.

Now, some of you may still be designing websites with tables and may be wondering if it’s worth it to keep reading. After all, you still can make a functioning website can’t you? The simple answer is no. Table based web design is bulky, hard to understand for beginners, and extremely inflexible to edit.

Tables in web design should be left only as data holders, not as design frames.

Tables were probably a primary way of web design for most of you. What could be more simple than making a table site in dreamweaver or an imageready slice-up in photoshop? Surprisingly CSS design is extremely easy to learn, much more so than tables. This even carries over to the extent that you need no more than notepad to make a functioning site with CSS.

Now then, some would ask what is CSS and why is it so important. CSS is short for Cascading Style Sheets. The beauty of CSS is that you can have only one html page and keep it the exact same, but it can change drastically in look based on the style sheet. Don’t believe it? Check out the marvels of css at http://www.csszengarden.com . Same html, different CSS.

CSS – basics

If you learned html quickly then CSS should be even faster. A basic CSS style would look something like this in html :

<style type=”text/css”>
body {
background: black;
color: white;
}
</style>

In this statement we have set all font to be the color white, and the background color of the page to be black. Now for the syntax of CSS.

.Class #id tag {
area:attribute;
}

Make sure to remember the semicolon on the end of the attribute, it can cause a lot of problems if you don’t.

Let’s start with the Class. A class in css is started with a . and can be used multiple times. Normally a class is used to contain areas, explained below.

Next is an ID. and ID is defined by a # and can only be used once. IDs are normally under a class.

The tag is the html attribute you wish to edit, like b, p, img, or a. It can also be nested, such as ul li.

The area is what is being called for change. A quick list to get you started :

background:black; – background color set to black (can use hex or RGB, explained later)

background-image: url(“images/image.png”); – background image

background-repeat:no-repeat; – stops the background for repeating, use repeat-x or y to get the image to repeat in one direction

font:georgia; – set the font to Georgia.

font-size:12px; – set the font size

color:white; – set the font color

margin: 5px 5px 5px 5px; – set all margins to 5px, area outside of the box font or objects are in. (order is up right down left)

padding: 5px 5px 5px 5px; – set padding to 5px, padding is how much space is inbetween the object and the container.

float:right; – float an element to the right of the scree, can also be left. (explained later)

clear:both; – clears floats so elements aren’t scattered randomly. (explained later)

width:200px; – set the width of an element.

Now you at least have a basic understanding of CSS. Now there are two ways to put a CSS style on your page, either localy on the page or embedded.

Local:

<style type=”text/css”></style>

Embed:

<link href=”style.css” rel=”stylesheet” type=”text/css” />

The beauty of embed is that the SAME sheet can be used on ALL pages making it easier to edit fonts and other items globaly without the hassle of editing every page. Simple yet extremely effective.

CSS – LAYOUTS

Now then some may still be wondering how CSS can replace tables for design. The float element. Make a new html document and a new css document in dreamweaver (or in notepad just save as all files and put .css on the end of it)

In the html document put this :

<html>

<link href=”style.css” rel=”stylesheet” type=”text/css” />

<div class=”main”>

<div id=”container”>

<div id=”header”><h1>Page title</h1></div>

<div id=”sidebarleft”>
random text! Hello world!
</div>

<div id=”content”>
more random text!
</div>

<div id=”footer”>
copywrite stuff
</div>

</div>

</html>

save it.

Now in the CSS document put this :

body  {
font: 100% Georgia;
background: #000000;
margin: 0;
padding: 0;
text-align: center;
color: #FFFFFF;
}
.Main #container {
width: 800px;
background: #FFFFFF;
margin: 0 auto;
text-align: left;
}
.Main #header {
background: #000000;
background-repeat:no-repeat;
padding: 10px 10px 10 px 10px;
}
.Main #header h1 {
margin: 0;
padding: 10px 0;
}
.Main h1 {
font-size:24px;
font-family:Georgia, “Times New Roman”, Times, serif;
}
.Main h2 {
font-size:20px;
font-family:Georgia, “Times New Roman”, Times, serif;
}
.Main #sidebar1 {
float: left;
width: 150px;
background: #FFFFFF;
padding: 15px 20px 0 0;
margin: 0 15px 0 0;
}

.Main #mainContent {
margin: 10px 15px 5px 10px;
padding: 10px 15px 5px 10px;
}

.Main #footer {
padding: 0 10px 0 20px;
color:#FFFFFF;
background:#000000;
}
.Main #footer p {
margin: 0;
padding: 5px 0;
}

save it as style.css

Open the page. You now have a CSS base to do whatever you will with to make a website out of. Play around with a few things and see where it can take you, experimentation is the best way to learn anything.

More to come now that I have some spare time.

Posted by: keystonelemur | October 7, 2008

Web Coding Basics

A quick tutorial for some of you who don’t understand HTML or CSS, just a basic one for now, I’ll expand upon it later.

Section 1- The Basics
HTML is one of the easiest languages to learn, but has many uses in comparison, making it a valuable asset in all of your projects. HTML is a globally accepted language in Web Design, and honestly I don’t get how anything could be made without understanding this base language, but you didn’t come here to listen to me rant, did you? On to the content then!

Tags are pretty simple, with almost all of them having an opening <> and a closing </>. All documents start with the same basic tags.
<html>
<title>Test Site!</title>
<body>
</body>
</html>

simple enough, eh? That’s all you need to have a website up, but then again, its just a blank page, where’s all the goodies?

<html>
<title>Test Site!</title>
<body>
<p>
WOW! A section title!
</p>
<p>
blah
</p>
</body>
</html>

ya, no… You have text, but that’s ALL it is, that’s not even close to a website, it might be good to make yourself feel warm and fuzzy inside that you made something in HTML, but that’s all it’s good for. Let’s get into some text tags to make this more interesting!

<b></b> – Bold tag
<i></i> – Italic tag
<u></u> – Underline tag
<h1></h1> – Header tag, can be 1-6 to make the size bigger/smaller

Let’s try this again now!

<html>
<title>Test Site!</title>
<body>
<h1>
WOW! A section title!
</h1>
<p>
blah blah blah blah <b>blah!</b>
</p>
</body>
</html>

better, but no good, all you have is still text, onto the next section then.

Section 2- Color

Color makes things more interesting to be honest, without it, all you have is black and white, which does absolutely nothing with aesthetics (how it looks…).
One more time with some color!

<html>
<title>Test Site!</title>
<body bgcolor=”black”>
<h1>
WOW! A section title!
</h1>
<p>
blah blah blah blah <b>blah!</b>
</p>
</body>
</html>

Ya, that was smart, you have a black BG, cool, eh? NO! You also have black text, good luck with that, now its not boring, its blank… lets try this again

<html>
<title>Test Site!</title>
<body bgcolor=”black”>
<h1><font color=”white”>
WOW! A section title!</font>
</h1>
<p><font color=”white”>
blah blah blah blah <b>blah!</b></font>
</p>
</body>
</html>

Ya, there we go, that’s actually readable, but honestly, who wants to go through all of that!? Lucky for you there’s css, which brings us to the next section.

Section 3- Hex Color
Hex is, put simply, your best friend, or your worst enemy. Hex color codes are in, as the name suggests, 6 digits, sometimes different, but I wont cover that here. The hex system has 16 numbers, as opposed to the decimal system. 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F. 00 is the lowest value, meaning 0, and FF being equal to 256, notice something? It’s similar to the RGB method, infact, it is, just in hex. 000000 is black, of course, with no value, and FFFFFF is white, with all value, and RGB is the order, so
FF0000 Red
00FF00 Green
0000FF Blue

I’m not going to go through all the math involved in hex, but the dead basic, as not to bore you
Decimal – Hex
1 – 16^1
10 – 16^2 (256)
100 – 16^3 (4096)

And if this rings a bell, you used windows 95, and hopefully trashed it by now, and its 256 colors of joy. Hoo-rah for 32-bit!

a color picker is very useful for these things, maybe color cop or something else, sourceforge is your friend tongue.gif

Section 4- CSS

This will save your life, quite literally. Your boss decides he wants another page, and a bunch more text with all red font, that leaves you to change EVERY LAST FREAKING FONT TAG. No fun, eh? Just hope you never learn the hard way. CSS can be a seperate text document that controls the style for MULTIPLE pages, making it easy to change it up, and lucky for you, its not hard to learn either! For not, lets start with just css in the document instead of external. If I catch you with font tags after this, you will die a most painful death(not really, just dont use them…)

<html>
<title>Test Site!</title>
<head>
<style type=”text/css”>
h1 {color: #ff0000}
h2 {color: white}
p {color: rgb(0,255,0)}
</style>
</head>
<body bgcolor=”black”>
<h1>
WOW! A section title!
</h1>
<p>
blah blah blah blah <b>blah!</b>
</p>
</body>
</html>

That’s better, no more evil font tags! In case you didnt notice, the three tags up there demonstrate the different ways to define color, hex, names, and rgb values.

Section 5- Background images/colors with css

here’s a basic rundown of how to get backgrounds to work using css

body
{
background: #FF0000;
}

A colored background

body
{
background: url(pic.gif) no-repeat top;
}

A pic with no repeat

body
{
background: #00FF00 url(pic.gif) no-repeat fixed top;
}

A pic with no repeat, and is fixed at the top of the screen

Section 6- Links and Images

Again, all you have is text, what fun is that? You need some images and some links to get the site running! Lets use an image as a link for this example

<html>
<title>Test Site!</title>
<head>
<style type=”text/css”>
h1 {color: #ff0000}
h2 {color: white}
p {color: rgb(0,255,0)}
a {color: green}
</style>
</head>
<body bgcolor=”black”>
<a href=”testsite.com”><img src=”testsite.com/banner.jpg” alt=”Our banner! yey!” border=”0″>
<h1>
WOW! A section title!
</h1>
<p>
blah blah blah blah <b>blah!</b>
</p>
</body>
</html>

just make sure you have the image, eh? You can use text instead, and notice that I changed the css too, now all links are green. MAKE SURE YOU HAVE BORDER=”0″ , lest you want a tacky blue border around your image(in this case, its now green blink.gif )

Section 7- Tables and Div(ision) tags

Two tags that are probably life savers in organizing things, the table and the div tag, but lets start with tables. Think Microsoft Excel, with columns and tables, same basic idea. Table utilizes <th> (table head), <tr> (table row), <td> (table block). (thanks mukou)

<table>
<tr>
<td>Apple</td>
<td>Orange</td>
</tr>
<tr>
<td>Strawberry</td>
<td>Bannana</td>
</tr>

That’ll make a 2×2 table with the information given, simple enough eh? <table bgcolor=””> can also be used

The div tag can be used to define sections, and as you’ll learn in further learning in css, classes are a lifesaver. CSS can define multiple classes in the div tag, meaning different color, font, size, and other things in each different class. I would explain it, but it’s one of those things that’s best for you to learn from the pros, they can explain it ALOT better than I can(/will, lol)

<div bgcolor=”red”>red section</div>
<div bgcolor=”green”>green section</div>

But do me a big favor and never use that combination, please, for the sake of soon to be color-blinded web-surfers, dont do it (read color tutorial below)

Conclusion
hope that helped

Programs-
Notepad ++
HTML Kit (also good for php[later tutorial])
Dreamweaver(good luck wih the cash wink.gif )

Color tutorial(also by me)
http://www.deviantart.com/deviation/56255162/

This will help explain the woes of color usage, make yourself look alittle more like a pro early with the right color combinations!

for more advanced learning in scripts, go to http://www.w3schools.com !

Till next time!

Posted by: keystonelemur | October 7, 2008

Winter is up and going

Some people have heard me rant on about how I’m going to finally get to making Winter Studios and all this. Ya, it’s Winter Design, a little less formal.

 

Regardless I’m probably going to be taking some lighter comissions and likewise. Currently working through some projects for my school and all of the other district sites.

 

Just got done with Carthage JH . Even with that it’s not like some bugs don’t still exist, shockingly enough it’s a problem with firefox for once… IE6 works and Firefox doesn’t, go figure eh?

What I probably will do is at least publish some tutorials and likewise to help get some people on their feet in terms of Photoshop and some other programs.

Categories