#中英之11
同場加映
#2022新書
#LittlePeaDrawingSchool
Little Pea's Drawing School
Discover Little Pea's Drawing School, where everyone is about to learn an important lesson about art, even the teacher!
Little Pea is now an accomplished artist--everyone knows it. One day, a friend of his encourages him to open a drawing school. What a marvelous idea! Shortly after, his first class is ready to attend his lessons, and everyone is working hard to improve their skills and techniques. Little Pea will soon learn that one does not always recognize a great artist at first glance.
#LittlePeaGrandJourney
Little Pea's Grand Journey
#小豆子的大冒險
What is the best solution to a creative dry spell? A grand journey!
Little Pea illustrates stamps for a living. He has painted insects, tomatoes, cars, and flowers. But what should he draw next? Short on inspiration, he sets off on a great journey and a quest for ideas in his bright red plane. Who knows where he will land!
#TheTinyTaleofLittlePea
The Tiny Tale of Little Pea
#小豆子
"When he was born, Little Pea was tiny. Teeny-tiny." His clothes were hand sewn by his mother and his shoes were hand-me-down doll shoes. As he grew older, Little Pea enjoyed climbing tomato plants, driving around in his wind-up car and riding on the backs of grasshoppers. But then Little Pea started school. And he suddenly realized just how small he was. Too small for his chair. Too small to play the flute. Too small for gym class. What would become of wee Little Pea?
#中英之11
同場加映
#2022新書
同時也有253部Youtube影片,追蹤數超過19萬的網紅Mateusz Urbanowicz,也在其Youtube影片中提到,In this, a bit different video I'm building a drawing board, or more exactly, converting a painting board into one. Feel free to check out my other s...
「hand drawing」的推薦目錄:
- 關於hand drawing 在 英該多看書 繪本與書籍 Facebook 的精選貼文
- 關於hand drawing 在 Taipei Ethereum Meetup Facebook 的最佳貼文
- 關於hand drawing 在 SU YANG , 蘇婭 Facebook 的最佳解答
- 關於hand drawing 在 Mateusz Urbanowicz Youtube 的精選貼文
- 關於hand drawing 在 Japanese Calligrapher Takumi Youtube 的最佳貼文
- 關於hand drawing 在 dP Art Drawing Youtube 的精選貼文
- 關於hand drawing 在 120 How to Draw Hands ideas - Pinterest 的評價
- 關於hand drawing 在 Free hand drawing on image in SwiftUI [closed] - Stack Overflow 的評價
- 關於hand drawing 在 Hand drawing - Home | Facebook 的評價
hand drawing 在 Taipei Ethereum Meetup Facebook 的最佳貼文
📜 [專欄新文章] Gas Efficient Card Drawing in Solidity
✍️ Ping Chen
📥 歡迎投稿: https://medium.com/taipei-ethereum-meetup #徵技術分享文 #使用心得 #教學文 #medium
Assign random numbers as the index of newly minted NFTs
Scenario
The fun of generative art NFT projects depends on randomness. The industry standard is “blind box”, where both the images’ serial number and the NFTs’ index are predetermined but will be shifted randomly when the selling period ends. (They call it “reveal”) This approach effectively solves the randomness issue. However, it also requires buyers to wait until the campaign terminates. What if buyers want to know the exact card right away? We’ll need a reliable onchain card drawing solution.
The creator of Astrogator🐊 isn’t a fan of blind boxes; instead, it thinks unpacking cards right after purchase is more interesting.
Spec
When initializing this NFT contract, the creator will determine the total supply of it. And there will be an iterable function that is randomly picking a number from the remaining pool. The number must be in range and must not collide with any existing ones.
Our top priority is accessibility/gas efficiency. Given that gas cost on Ethereum is damn high nowadays, we need an elegant algorithm to control gas expanse at an acceptable range.
Achieving robust randomness isn’t the primary goal here. We assume there’s no strong financial incentive to cheat, so the RNG isn’t specified. Implementers can bring their own source of randomness that they think is good enough.
Implementation
Overview
The implementation is pretty short and straightforward. Imagine there’s an array that contains all remaining(unsold) cards. When drawIndex() is called, it generates a (uniform) random seed to draw a card from the array, shortens the array, and returns the selected card.
Algorithm
Drawing X cards from a deck with the same X amount of cards is equal to shuffling the deck and dealing them sequentially. It’s not a surprise that our algorithm is similar to random shuffling, and the only difference is turning that classic algo into an interactive version.
A typical random shuffle looks like this: for an array with N elements, you randomly pick a number i in (0,N), swap array[0] and array[i], then choose another number i in (1,N), swap array[1] and array[i], and so on. Eventually, you’ll get a mathematically random array in O(N) time.
So, the concept of our random card dealing is the same. When a user mints a new card, the smart contract picks a number in the array as NFT index, then grabs a number from the tail to fill the vacancy, in order to keep the array continuous.
Tweak
Furthermore, as long as the space of the NFT index is known, we don’t need to declare/initialize an array(which is super gas-intensive). Instead, assume there’s such an array that the n-th element is n, we don’t actually initialize it (so it is an array only contains “0”) until the rule is broken.
For the convenience of explanation, let’s call that mapping cache. If cache[i] is empty, it should be interpreted as i instead of 0. On the other hand, when a number is chosen and used, we’ll need to fill it up with another unused number. An intuitive method is to pick a number from the end of the array, since the length of the array is going to decrease by 1.
By doing so, the gas cost in the worst-case scenario is bound to be constant.
Performance and limitation
Comparing with the normal ascending index NFT minting, our random NFT implementation requires two extra SSTORE and one extra SLOAD, which cost 12600 ~ 27600 (5000+20000+2600) excess gas per token minted.
Theoretically, any instantly generated onchain random number is vulnerable. We can restrict contract interaction to mitigate risk. The mitigation is far from perfect, but it is the tradeoff that we have to accept.
ping.eth
Gas Efficient Card Drawing in Solidity was originally published in Taipei Ethereum Meetup on Medium, where people are continuing the conversation by highlighting and responding to this story.
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hand drawing 在 SU YANG , 蘇婭 Facebook 的最佳解答
聖靈請你來充滿我心
作詞:Caroline Tjen
作曲:Caroline Tjen
聖靈請你來充滿我心
我需要你恩膏 充滿我靈
聖靈啊我好愛你
我的靈讓你牽引
而每一天我要更深愛你
我要追求你主
我將生命獻給你
牽引我更親近你
你大能更新我靈
無人能與你相比
主我仰望你的榮面
我敬拜你在靈與真理裡
【Come Holy Spirit】
Come Holy Spirit fall on me now
I need your anointing come in your power
I love you holy spirit
You're captivating my soul
and everyday i grow to love you more
I'm reaching for your heart
You hold my life in your hand
Drawing me closer to you
I feel your power renew
Nothing compares to this place
Where i can see you face to face
I worship you in spirit and in truth
https://youtu.be/6uxa1PlpW-U
🕊🦋🕊🦋🕊🦋🕊🦋🕊🦋🕊🦋🕊🦋
hand drawing 在 Mateusz Urbanowicz Youtube 的精選貼文
In this, a bit different video I'm building a drawing board, or more exactly, converting a painting board into one.
Feel free to check out my other stuff:
Gumroad: https://gumroad.com/mateusz_urbanowicz
Patreon: https://www.patreon.com/mateuszurbanowicz
Website: http://mateuszurbanowicz.com
Blog: https://artvsentropy.wordpress.com/
Twitter: https://twitter.com/gommatt
Instagram: https://www.instagram.com/mateusz_urbanowicz
hand drawing 在 Japanese Calligrapher Takumi Youtube 的最佳貼文
Amazing hand drawing and writing | Japanese cartoon
hand drawing 在 dP Art Drawing Youtube 的精選貼文
I drew and counted the dots in my drawing.
It took me more than 7 days to mark 182336 and finish this drawing .
I use click software to count the number of dots.
My right hand is drawing and my left hand is clicking at the same time, to accurately count the number of dots on a drawing .
#DotsDrawing #DPARTDRAWING #182336Dots
follow me :
YOUTUBE : https://www.youtube.com/dpARTDRAWING
FACEBOOK : https://www.facebook.com/DPartDrawing
INSTAGRAM : https://www.instagram.com/dp_art_Drawing
hand drawing 在 Hand drawing - Home | Facebook 的推薦與評價
Hand drawing, Puan, Davao City, Philippines. 748 likes · 1 talking about this. You make time because you know that Facebook has over 400 million users.... ... <看更多>
hand drawing 在 120 How to Draw Hands ideas - Pinterest 的推薦與評價
Oct 24, 2020 - Learn how to draw hands and fingers. See more ideas about how to draw hands, drawing tutorial, drawings. ... <看更多>