Posted by Sameer on 11:10 AM
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Check out these videos. Experience a whole new level of technology.










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Posted by Sameer on 3:49 AM
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Recently, I attended a robotic workshop from Technophilia institute, Mumbai. The workshop covered modules of microcontroller programming. While learning about IR(Infra Red) standards, I understood the idea of an obstacle detector bot. I bought 2 obstacle detectors and the ATMEGA16 microcontroller from the institute and made my bot:



Building materials are:

1. Two DC-motors
2. Two wheels
3. ATMEGA16 microcontroller
4. IR obstacle detectors
5. 12V lead-acid battery

Steps followed:

1. This time, I needed a stronger body than the nokia box since I had to mount the PCB(Printed Circuit Board) as well as the obstacle detctors on it. So I made one using ply-wood.


2. Then, I fixed 2 DC motors in the body and one supporting wheel in a same way as I have done previously in my movement bot.





3. In the next step, The microcontroller PCB and the obstacle detectors got their place and my bot was ready. This process took a one and half day.

4. The next part was vital but very easy and less time consuming and that was to program my robot. Using a software called WinAVR I programmed the IC ATMEGA16 to work as an obstacle detector.


Functioning:

1. The IR obstacle detector mounted on my bot has a transmitter and a receiver.

2. It has one IC which continuously sends logical 1 to transmitter pin. This causes the transmitter to emit infra-red rays in forward direction. The IR ways travel upto a certain distance and then die off.



3. If any obstacle comes within that distance the rays are reflected and are received by the transmitter.

4. When the transmitter receives waves, Logical 1 appears at that pin. My job is to detect this 'Logical 1' at regualr intervals.

5. When my program founds that IR rays have reached the transmitter, it orders the bot to turn. i.e. I move one motor backward and the other in forward direction.

It's a simple if_else structure within an infinte while loop.

while(1)
{
if('Logical 1 is detected')
Order the bot to turn
else
Order the bot to go straight.
}

6. The second obstacle detector on the right is used to control the direction of the turn. If 'Logical 1' is detected at receivers of both detectors, imply that there is an obstacle to the right as well as in the front. In such a case, I order my bot to turn to the left instead of right.



De-merits:

1. Only those obstacles can be detected which are in front of the transmitter since IR rays travel in nearly straight forward direction.

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Thanks to all for helping. Programming is done is language C.

Posted by Sameer on 7:48 AM
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While searching some stuff on the net, I found this design of the robot. The thing which attacted me was the mechanism of driving wheels using rubber bands. I loved this idea since it enables one to rotate those wheels which don't have the diameter of their central hole equal to the axle of the motor.


I decided to make a similar robot. Here's the bot I've made:




Building materials used are:

1. DC Motors
2. Two driven wheels(Or something which looks like a wheel), I've used a part of a sewing machine(Unknown to me). I found it in Tailor's shop.
3. Supporting wheels
4. 9V Batteries.
5. A pipe(as the path)


Steps followed:

1. First step was to make the actual functioning body of my robot. I tied 2 DC motors and driven wheels together using a tape. It looked like this:




2. The gap between the two wheels was adjusted so that the pipe easily fits in between.



3. Then I made the holder for supporting wheels using a copper wire and mounted them on it.

4. The holder is designed with a gap in the middle for the pipe.

Function:

1. When the motors are connected to battery they start rotating.

2. Since a rubber band is passed over the axle of the motor and the wheel, Rotation of motor also drives the wheel.

3. The rubber band acts as a belt. Thus the energy is transmitted from the motor to the wheel.



4. Note that the wheel will only rotate if the rubber band is streched tight over the axle and the wheel. If the rubber band is loose the wheel will not rotate. The reason is, The energy is transmitted only when the rubber band is under tension and there is friction present is between the wheels and the rubber band.

5. If the pipe is put in the gap between the two wheels, the bot pulls or draws out the pipe depending on the terminals of the battery.

6. If the pipe is stationary(fixed), the bot travels along the pipe forward or backward .

7. The gap between two driven wheels can be adjusted for different diameters of the pipe. In a way, we can call him simple line-tracker bot made without use of any sensors.



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Thanks to all for helping.


Posted by Sameer on 7:41 AM
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Before entering into complexity, I decided to make a bot which can be controlled from a distance using remote. This wired bot can move in forward as well as backward directions, can turn and also rotate about itself. The purpose was to study the electrical connections required to control a bot.The building materials used were:

1. 2 DC motors. (Motors working on DC supply which can rotate in both directions.)
2. 4 two-way-switches
3. 2 wheels.
4. 9V battery.
5. Other raw material to build the body. (I used the 'Nokia' box).

Here's the bot I've made.






Steps followed:

1. Making the body was the simple task. I just installed DC motors in the 'NOKIA' box and then connected wheels to them.

2. To make the remote, I used a plastic box which can accommodate 4 two-way switches and fixed them as shown. Left 2 switches are used to control left motor and right 2 switches are used to control right motor.






3. The reason behind using two-way switches follows a story. First of all, I tried making a remote using 4 one-way switches and a battery. However, it was found that this idea required more than 1 battery to control the bot hence was neglected. After this, I thought of a circuit which uses 2 four-way switches, one for controlling each motor. This time the problem was to find four-way switches in the market. But then using 4 two-switches I successfully managed to convert them into 2 four-way switches and my problem got solved. It took me around 2 months to tackle this riddle.


















If two blue squares are closed, +ve of the motor connects to +ve of battery and -ve of the motor connects to -ve of battery. Therefore, the motor revolves in forward direction.
If two red squares are closed, +ve of the motor connects to -ve of battery and -ve of the motor connects to +ve of battery. Therefore, the motor revolves in backward direction.

4. I then attached the third supporting wheel to the body and my bot was complete.

5. The thing which I learned was the circuit. I can now use the same remote for controlling movements of any wired bot.

Note: The type of this bot is Differnetial-type drive. There are two more types viz. Car-type and sychronized-type.



Two-way switches and converting them to four-way switches:




In the left diagram, the bulb glows in both situations by the use of a two-way switch. Right diagram shows how 2 two-way switches can be combined to form a four-way switch.





Drawbacks I observed:

1. Since both motors are operated independent of each other, one motor may rotate at a faster speed than the other. Due to which, the bot may move along a curve even when we want him to move in a straight line.
2. To turn the bot, either we can switch off the right motor so that it turns right. Or we can switch off the left motor so that it turns left. The point is, while turning the bot rotates about a vertical axis passing through the switched-off motor. As a result, the bot is not able to turn while moving forward or backward.

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Thanks to all who helped me.

Posted by Sameer on 12:02 AM


In this post, I'm introducing to you a type of graphics which has the nature exactly opposite to the Cel-shaded graphics. Cel shading is used to give a comic effect to objects whereas Pixel Shading is used to make objects appear more real. As the name suggests, in this graphics a single pixel is coloured and many such pixels brought together produce the required image.

What is a pixel?

A pixel is the smallest unit of an image. They are arranged in 2-Dimensional grid and are often represented using dots, squares and rectangles. Each image on computer is made of pixels. These pixels can be observed by holding a magnifying glass in front of the computer screen. Or when you draw some picture in paint, magnify it and observe. You shall see even the smooth curves to be made of rectangular pixels.






Now, Let's do something very interesting.

1. Open MS Paint. Open a 'New' drawing.
2. Access the 'Image' menu and click on 'Attributes'.



3. A window opens. Set Width=7 and Height=1. Make sure that units are in pixels.
4. The drawable area shrinks to very small size. 'Zoom' the image from the 'view' menu.




















5. By using pencil, fill each block of drawable area with colour of your choice. Each block represents a pixel.
6. Save this image and set it as desktop background.




7. You can increase the number of shades by increasing width.

So, as you can see, By painting each single pixel and then placing such pixels side by side, a beautiful wallpaper has shown up.

The pixel shading is also done in a similar manner. A pixel shader computes colour and other attributes for each pixel. Other attributes include lightning, bump mapping, shadows, translucency, depth etc. Many such pixels, which are designed independent of each other, when brought together produce the required pixel shaded image, scene, i.e the texture.


Once the texture becomes ready it is applied on the required 3-D object. It is similar to that when we wrap an object in a paper. Paper here is the texture. We draw the design on the paper(Design the texture) and apply it on the object(Apply the texture to the object).

Unlike cel-shading, Pixel shader contains various shades of a color which make the object appear more realistic.



Observe these two images.Especially the material applied on Tyre of bike and the girl's frock.






The various attributes like Bump mapping, Z-buffering etc. which are applied to the pixel will be discussed in later posts. Here are more examples of Pixel Shading.
























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Thanks to Siddhesh for help. This post needs to be improvised. If you have any suggestions or content, please let me know. Thank you.


Posted by Sameer on 12:05 AM
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I made this little guy just to study the rotation of motors. And thus, Murloc jumped out of the water.












Construction was pretty simple. I took following materials and tools for building this tiny.
1. DC motor with plastic gear box
2. 9V battery
3. Paper clips
4. Wheels





























Steps followed:

1. Attach 2 DC motors to each other which forms base as well as body for the bot.

2. Mount 9V battery on this base using a tape. The terminals of the battery appear as eyes of the bot.



3. Attach two wheels, one to each motor.

4. Attach one extra wheel or some object that can roll with the help of a paper clip, so that the bot can stand on three wheels.












5. Connect both motors to the battery.

6. Instead of using wheels, one can also use clips to make 'Murloc' jump.


Jumping murloc can climb heights. It dies when battery discharges.

Posted by Sameer on 2:40 AM
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Yup, quite late, but my blog just can not miss this one.

So, Here's Joker with his super dynamites to blow the things out of proportion.



1. "I am an Agent of Chaos!"

2. Why so serious?

3. I believe whatever doesn't kill you simply makes you... stranger.

4. See, I'm a man of simple tastes. I like gunpowder...and dynamite...and gasoline! Do you know what all of these things have in common? They're cheap!

5. This town deserves a better class of criminal... and I'm gonna give it to them. Tell your men they work for me now. This is 'my' city.

6. You see, madness, as you know, is like gravity. All it takes is a little push!


7. Do u know why I prefer knives?..Guns are two quick,You cant savor all those little emotions...In their last moments people show you who they really are...So...In a way I know your friends better than you ever really did. Would u like to know which of them were cowards?

8. Who would I play with if i kill you?

9. Why don't we cut you up into little pieces and feed you to your pooches, hmm? And then we'll see how loyal a hungry dog REALLY is!

10. You die as a hero or live long enough to see yourself become a villain.The only sensible way to live in this world is to live without a rule.

11. GAMBOL: What do you suggest we do...???
JOKER: Kill the Batman...!!!!
GAMBOL: Then why haven't you done it as yet..???
JOKER: When you are good at something never do it for free..!

12. "You just couldn't let me go could you? This is what happens when an unstoppable force meets an immovable object. You truly are incorruptible aren't you? You won't kill me out of some misplaced sense of self-righteousness, and I won't kill you, because you're just too much..... fun. I think you and I are destined to do this forever."

13. You look nervous. Is it the scars? You want to know how I got them? Come here. Hey, look at me. So I had a wife, beautiful; like you. Who tells me, I worry too much. Who tells me, I ought to smile more. Who gambles, and gets in deep with sharks. One day they carve her face. We have no money for surgeries. She can't take it! I just want to see her smile again. I just want her to know that I don't care about the scars. So I stick a razor in my mouth and do this...

14. Wanna know how I got these scars? My father was....a drinker. And a fiend. And one night he goes off crazier than usual. Mommy gets the kitchen knife to defend herself. He doesn't like that. Not. One. Bit. So, me watching, he takes the knife to her, laughing while he does it. Turns to me and he says "Why so serious?" Comes at me with the knife,"Why so serious?" He sticks the blade in my mouth. "Lets put a smile on that face!" And..... Why so serious?


15. (Batman bangs joker's head)Joker: Never start with the head. The victim gets all fuzzy and can not feel the rest pain.(Batman hits his hands)Joker: see...

16. We made it.. Good evening ladies and Gentlemen.. We are here for tonight's entertainment... I have only one question.. Where is Harvey Dent?



17. I just did what I do best. I took your little plan and I turned it on itself. Look what I did to this city with a few drums of gas and a couple of bullets. Hmmm? You know... You know what I've noticed? Nobody panics when things go "according to plan." Even if the plan is horrifying! If, tomorrow, I tell the press that, like, a gang banger will get shot, or a truckload of soldiers will be blown up, nobody panics, because it's all "part of the plan." But when I say that one little old mayor will die, well then everyone loses their minds!

18. I had a vision of a world without the Batman,
The mob grounded out a little profit,
The police trying to shut them down 1 block at a time,
and it was so boring.....

19. Do I really look like a guy with a plan? You know what I am? I'm a dog chasing cars. I wouldn't know what to do with one if I caught it! You know, I just do things. The mob has plans, the cops have plans. Gordon's got plans. They're schemers. Schemers trying to control their little worlds. I'm not a schemer. I try to show the schemers how pathetic their attempts to control things really are.So, when I say that you and your girlfriend was nothing personal, you know that I'm telling the truth.


20. Gordon:Where's Harvey Dent?
Joker: What is the time??
Gordon: What's time got to do with that?
Joker: Oh,Depending on the time he may be at one place or in several.
Gordon: OK,So you Want To Play a Game,Right?(releasing joker's handcuffs)
JOKER(seeing GORDON releasing him):The same Bad cop Good cop routine.

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Reference: The Dark Knight(Movie)
Lead Cast: Christian Bale(The Batman), Heath Ledger(The Joker)
Something about: We might see Christian Bale as Batman in upcoming movies but unfortunately we won't see The Joker. Some people are born to do something....amazing, beautiful and that which can not be challenged. We might wonder, What would have happened if he was to die 'before' instead dying 'after'. Perhaps, the time wraps them only when they have finished their job. They live for that legendary role. Heath Ledger died from an accidental toxic combination of prescription drugs. A few months before his death, Ledger had finished filming his penultimate performance, as the Joker in The Dark Knight. He received about 31 awards for the best actor and the best villain for his role. He gifted the world with 'Joker' and now rests in peace.

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Watch this movie. It's nice. A true masterpiece.

Posted by Sameer on 4:13 AM
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I've introduced a new category, GFX(Graphics) and Technical Drawing. It's an attempt to show and share with people, the information I've collected or received about technical aspect of drawings and paintings.

Posts of this category will contain stuff about Computer graphics, Technical drawing and it's implementation in games,physics stimulation, media entertainment and academics .

Thank you!:)

Posted by Sameer on 1:49 AM

In this post, I'm going to introduce to you,one of the most beautiful and spectacular types of computer graphics,'Cel-Shading'.


Cell Shading) is a non-realistic rendering designed to make Computer graphics to be hand-drawn. Rendering is the process of producing virtual computer graphics which are used in gaming,entertainment industries or in stimulations.

The cel-shaded object appears to be an object in cartoons or in comics. By using Cel-Shading, we can draw lovely cartoons on our computer which were used to be hand-drawn before.


Now,Let's understand 'how a cell-shaded object differs from a real one'. But before that, I need you to recollect the paintings which you have drawn in Paint or PowerPoint etc.



Do you remember this window? Yup, It's a window from paint and is used to generate colours which are not available in the colour box. You can form the desired colour by dragging the mouse pointer over or you can enter the values for three fundamental colours,Red,Green and Blue to form a particular shade.Now observe the following drawing:



As you can see, I've drawn bands of various shades of a colour. The numbers indicate the amount of red color present in the shade.

When you see a real-life object you don't see a perticular colour but various shades of that colour.Just as the bands I've drawn above. See the car below:

Cel-shaders are different in nature. In cel-shaded animation, an intermediate colour from a group of close shades is selected and that is used to paint the object. Confused? Observe below...



The colour shade having RED=225 is selected from group 200-255. The colour shade having RED=175 is selected from group 150-200. These two shades are put side by side, eliminating all the other shades in between. See the cel-shaded car.


The bottom section of the car is darkish shade of green.However, the shade changes abruptly as we move from bottom to the top section and it becomes light green.

Property 1: In cel-shading all the shades of a particular colour which are very close to each other are represented by a single colour and used to paint the object. The selected shade is not changed unless and until there's a drastic change in the colour of the object. Drastic change refers to 1. Change of surface 2. Direction of light 3.Completely different colour(say one surface is Red and the other is Blue).


Ok,Let's move to the next point. Observe the following painting. It seems like an ancient tomb. Anyways, It's cel-shaded as you can clearly see. The point to be noted is, all the boundaries of each and every object in the painting are drawn, which you don't see in the real-life object.



Following images also illustrate the fact.
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Property 2: Thus, In a cell-shaded object all the boundaries are drawn very clearly.

Here are some more cell shaded objects:

The Grand Cannon-----Teapot



Due to the above properties and some other and it's beauty, Cel-shading is becoming very popular nowadays. It is a relatively recent addition to computer graphics, most commonly turning up in console video games.



The recent Computer/Console games which have used cel-shaders are Prince of Persia 2008, No more heroes etc.








I hope, You would love this powerful and fabulous art of drawing.

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Want to know more about games? Visit:
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Note:Though the end result of cel-shading has a very simplistic feel like that of hand-drawn animation, the process is complex. Softwares like 3ds-max provide ready made cel-shaded textures. Soon, I'll be posting a tutorial on 'how to apply cel-shading to an object'.