Question about effect!

Alex

Hi,


I have question about this effect in this link

(http://www.tcax.org/forum.php?mo ... &extra=page%3D1)

I think he used curve to make this effect, so my question is how can we make this effect by using Lua ?

I'm not good in Python to understand his code and rewrite in Lua

Alex

Thank u Bro

Alex

I understand some things ..I will try the to do it
but If there is lua example (simple) it will be better, or if u can tell that man who wrote a LUA version

Regards

Alex

Ok
I came with question

1. max(pt_num, maxi)

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max here it same like interpolate function in auto.4 right?

1. function interpolate(pct, min, max)

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Alex

Yep, I had already sent your request to some members who both knew python and Lua, but I'm not sure whether they have enough interest or time to rewrite.

I really appreciate that, if they cant at less i need them help

and I really try to understand ur demo script and I'm trying to write by myself, if i have question i will ask you
question i will put here with my code

thanks

Alex

this is my  simple code, but i didn't get the right result  (NyuFx)

1.         local l = table.copy(line)
   
2.         for si,syl in pairs(line.syls) do
   
3. 
   
4.                    for pi, pixel in ipairs(convert.text_to_pixels(syl.text, line.styleref, syl.left % 1,  y % 1)) do   
   
5. 
   
6.                 local x, y = syl.left + pixel.x,syl.y + pixel.y
   
7. 
   
8.                 local points = {
   
9.                                 {x, y},
   
10.                                 {x + rand(50,50), y+rand(-30,40)},
    
11.                                 {x + rand(50,50), y+rand(30,90)},
    
12.                                 {x + rand(-100,100), y + rand(-50,50)},
    
13.                                 {x + rand(-50,50), y + rand(-70,70)},
    
14.                                 {x + rand(-70,70), y + rand(-40,40) }
    
15.                               }
    
16. 
    
17.                 local  start_t = line.start_time + syl.start_time
    
18.                 local  end_t = line.start_time + syl.start_time + 400
    
19. 
    
20.                         local tt = Interpolate(#pixel,start_t, end_t)
    
21.                         local x_cur, y_cur = bezier_curve(#pixel, points)
    
22. 
    
23.                         l.start_time = tt
    
24.                         l.end_time = tt + 300
    
25.                         l.text = string.format("{\\an7\\pos("..x_cur..","..y_cur..")\\bord0\\1c&Hffffff&\\fscx150\\fscy150\\p1}").."m 0 0 l 1 0 l 1 1 l 0 1 l 0 0 "
    
26.                         Output(l)
    
27. 
    
28.                   end
    
29.         end

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-

depending on your experience, what are the things missing?

Alex

thank you showjim, I appreciate that

this is the both function

1. function bezier_curve(pct, p)
   
2. 
   
3.         local function fac(n)
   
4.                 local k = 1
   
5.                 if n > 1 then
   
6.                         for i=2, n do
   
7.                                 k = k * i
   
8.                         end
   
9.                 end
   
10.                 return k
    
11.         end
    
12. 
    
13.         local function bin(i, n)
    
14.                 return fac(n) / (fac(i) * fac(n-i))
    
15.         end
    
16. 
    
17.         local function bernstein(pct, i, n)
    
18.                 return bin(i, n) * math.pow(pct,i) * math.pow((1 - pct), n - i)
    
19.         end
    
20. 
    
21. 
    
22.         if pct < 0 or pct > 1 or table.maxn(p) < 2 then
    
23.                 return nil
    
24.         end
    
25.         for i, v in ipairs(p) do
    
26.                 if type(v[1]) ~= "number" or type(v[2]) ~= "number" then
    
27.                         return nil
    
28.                 end
    
29.         end
    
30. 
    
31.         local x, y, z = 0, 0, 0
    
32.         local n = table.maxn(p) - 1
    
33.         for i=0, n do
    
34.                 local bern = bernstein(pct, i, n)
    
35.                 x = x + p[i+1][1] * bern
    
36.                 y = y + p[i+1][2] * bern
    
37.                 z = z + (p[i+1][3] or 0) * bern
    
38.         end
    
39.         return x, y, z
    
40. end

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other one

1. function math.bezier(pct, p)
   
2.         if type(pct) ~= "number" or type(p) ~= "table" then
   
3.                 error("number and table expected", 2)
   
4.         elseif pct < 0 or pct > 1 or #p < 2 then
   
5.                 error("invalid arguments", 2)
   
6.         end
   
7.         for i, v in ipairs(p) do
   
8.                 if type(v[1]) ~= "number" or type(v[2]) ~= "number" or (type(v[3]) ~= "number" and type(v[3]) ~= "nil") then
   
9.                         error("invalid table content", 2)
   
10.                 end
    
11.         end
    
12.         --Factorial
    
13.         local function fac(n)
    
14.                 local k = 1
    
15.                 if n > 1 then
    
16.                         for i=2, n do
    
17.                                 k = k * i
    
18.                         end
    
19.                 end
    
20.                 return k
    
21.         end
    
22.         --Binomial coefficient
    
23.         local function bin(i, n)
    
24.                 return fac(n) / (fac(i) * fac(n-i))
    
25.         end
    
26.         --Bernstein polynom
    
27.         local function bernstein(pct, i, n)
    
28.                 return bin(i, n) * pct^i * (1 - pct)^(n - i)
    
29.         end
    
30.         --Calculate coordinate
    
31.         local point = {0, 0, 0}
    
32.         local n = #p - 1
    
33.         for i=0, n do
    
34.                 local bern = bernstein(pct, i, n)
    
35.                 point[1] = point[1] + p[i+1][1] * bern
    
36.                 point[2] = point[2] + p[i+1][2] * bern
    
37.                 point[3] = point[3] + (p[i+1][3] or 0) * bern
    
38.         end
    
39.         return point
    
40. end

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Interpolate function

1. function utils.interpolate(pct, val1, val2, calc)
   
2.         if type(pct) ~= "number" or
   
3.         not (
   
4.                 (type(val1) == "number" and type(val2) == "number") or
   
5.                 (type(val1) == "string" and type(val2) == "string")
   
6.         ) or
   
7.         (type(calc) ~= "string" and type(calc) ~= "number" and type(calc) ~= "nil") then
   
8.                 error("number and 2 numbers or 2 strings and optional string expected", 2)
   
9.         end
   
10.         -- Calculate percent value depending on calculation mode
    
11.         if calc ~= nil then
    
12.                 if type(calc) == "number" then
    
13.                         pct = pct^calc
    
14.                 elseif calc == "curve_up" then
    
15.                         pct = (math.sin( -math.pi/2 + pct * math.pi*2) + 1) / 2
    
16.                 elseif calc == "curve_down" then
    
17.                         pct = 1 - (math.sin( -math.pi/2 + pct * math.pi*2) + 1) / 2
    
18.                 else
    
19.                         error("valid last value expected", 2)
    
20.                 end
    
21.         end
    
22.         -- Interpolate numbers
    
23.         if type(val1) == "number" then
    
24.                 return val1 + (val2 - val1) * pct
    
25.         -- Interpolate strings
    
26.         else
    
27.                 -- RGB
    
28.                 local r1, g1, b1 = convert.ass_to_rgb(val1)
    
29.                 local r2, g2, b2 = convert.ass_to_rgb(val2)
    
30.                 if b1 and b2 then
    
31.                         return convert.rgb_to_ass((r2 - r1) * pct + r1, (g2 - g1) * pct + g1, (b2 - b1) * pct + b1)
    
32.                 end
    
33.                 -- Alpha
    
34.                 local a1 = convert.ass_to_a(val1)
    
35.                 local a2 = convert.ass_to_a(val2)
    
36.                 if a1 and a2 then
    
37.                         return convert.a_to_ass((a2 - a1) * pct + a1)
    
38.                 end
    
39.                 -- Invalid string
    
40.                 error("invalid strings", 2)
    
41.         end
    
42. end

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Alex

No,
we can do curve effect by using pos tag, no need move tag

Alex

I used before but the result was same, i will try again soon with move tag
and I hope to get a satisfactory result