C

    On a very hot day，it can be hard to know what to do to feel good．If we run around，we may feel dizzy and sick to our stomachs．This is because our body can't get rid of the extra heat．However，if we just sit and do nothing，we may feel restless and bored．Are there things we can do to feel good when we are hot? Yes! Playing in water is one way to feel cooler．Of course，people with a pool，river，lake or ocean nearby can play in the water very conveniently．People don't have these can still play in water too．Taking a cool bath or shower can feel good on a hot day．On hot days，you can lose two gallons(加仑)of water in one day，so many doctors agree that you should try to drink at least 16 glasses of water to keep the water balance in your body． Mixing a little juice into your water is a good way to help you drink plenty of water．The food we eat also makes a difference in how we feel in the heat．Cold foods，such as ice cream and drinks with some ice can cool down our bodies．Fruits and vegetables are easy for the body and refreshing．Plan a healthy menu for a hot day．

    The sun, the moon and the stars are all in the sky. We see the moon and the stars at night. The sun is a ball. It's much bigger than the moon. It gives us heat (热量). The sun has a family. It's the biggest member of the family. The moon is a ball, too, like the sun and the earth. Sometimes it looks as round as a plate (盘子). Sometimes it looks half a plate. It looks bigger because it's much nearer to the earth. It's much smaller than the sun. It's smaller than the stars. The light (光) on the moon comes from the sun. It has no light of its own.

    The stars look smaller than the sun. They look small because they are very far away from us. All day the stars are in the sky. But the light from the sun is too bright. We can't see the stars in the day.

Computer

    There are all kinds of machines. They are used in many different ways. One kind of machines is called computer. A computer can do many things. A computer can do maths problems. People can do maths problems,too. But they can't do it as fast as a computer. Computers remember things. Computers remember everything people tell them. People can not remember as many things as computers. Computers help to tell what the weather will be like. Computers help to fly rockets and spaceships.

    There are a lot of ways computers are used. They are used in thousands of ways. But they are not alwaysused in the same way. Some computers do just a few things. Some computers can do a lot of things. There are huge (巨大的) computers. There are small computers, too. There may be computers in your school. Do you know what they do?

    Virtual (虚拟的)reality is a way to create a computer-made environment that brings the user into a virtual world. If you ever have put on a VR headset, you would know exactly what I am talking about. From an experiential view we do understand the idea, but what about the technical backend that goes into making it all possible? In this blog, we will understand the technology behind virtual reality and the basic terms about the development of a virtual ecosystem for a VR headset.

    The primary subject of virtual reality is simulating (模拟)the vision. Every headset is to perfect their method to create an immersive (浸人式)3D environment. Each VR headset puts up a screen or two in front of eyes, keeping the user away from any interaction with the real world. Two autofocus lenses (自动对焦镜片)are generally placed between the screen and the eyes that change based on eye movement and positioning. The vision appears on the screen either by using a mobile phone or HDMI line connected to a PC.

    To create a truly immersive virtual reality, there are certain requirements a frame rate (帧 率)of at least 60 fps, a refresh rate and at least 100﹣degree field of view (though 180 degrees is perfect). If either of these doesn't work according to the standards, the user will experience too big of a time difference between their actions and the response from the screen. We need the response to be less than 20 ms (1/1000 second) to fool the brain which is achieved by joining all the above in the right proportion (比例).Another matter that needs to be looked at here is to prevent netsickness because of the differences between the frame rate and refresh rate.

    Apart from the image, there are certain other things that go into creating an immersive VR experience, holding the user's attention completely in the virtual environment. For example, sound effects, when put with the image, can create very attractive effects. By using a headphone and 3D sound effects, the user can totally believe in the virtual environment. While perfecting sound effects, proper care needs to be taken about the consistency (一致)between the pictures and the sound. If you start playing frightening music in the background of a happy scene, it will just put the user off.

    In future, we will see rapid progress in creating a truly immersive digital experience. With leading players like Google, Microsoft, Oculus, and HTC making great efforts to improve the capabilities (性能),we are not far from achieving a virtual reality that would feel so much better than the real world. If you would like to develop a VR app for your business, then feel free to get in touch. With over 10 years of experience in mobile technologies, we can make every dream a reality.