More on .RAW

TheZsterBunny · **Posted:** Fri Aug 20, 2004 4:15 pm

I give up. I've tried all day, but I cannot figure out what i'm doing wrong.

I would very much like to learn how that program was done

-Z

RaPsCaLLioN · **Posted:** Fri Aug 20, 2004 6:07 pm

Do you know the equation for rotation? Just make an array that stores 3 coordinates for each point (X, Y, Z) - rotate each accordingly - same equation for any axis. And just draw the 'screen' x/y coordinates.

I don't make any sense...
I'll post the code but it doesn't make much more sense than I do. Let me play around w/ it a bit more first.

Mazer · **Posted:** Fri Aug 20, 2004 6:11 pm

I'm a bit curious, how is the Z sorting done? Just taking the average Z coord for each face and sorting them based on that?

RaPsCaLLioN · **Posted:** Sat Aug 21, 2004 7:44 am

Yep. So there are some cases where the display would be wrong because the avg of a polygon that should be located further away may be closer than the avg of an up front polygon.

code:

__ __
_I__I______I I___
I__________ I I___I
I I I I
I I I I
I I I I
I I I I
I I I I
_I I______I__I__
I_I I____________I
I__I I__I

This is another example of polygons that wouldn't be displayed right.

TheZsterBunny · **Posted:** Sat Aug 21, 2004 7:45 am

WHat is the rotation code?

I have a nifty way of keeping the shape stored, but rotation is giving me difficulties.

code:

type poly :
record
x : array 1 .. 3 of real
y : array 1 .. 3 of real
z : array 1 .. 3 of real
end record
var shape : flexible array 1 .. 1 of poly
var input : int
var filename : string
put "Enter File Name followed by .raw: " ..
get filename
assert length (filename) > 4 and filename (* -3 .. *) = ".raw" and File.Exists (filename)
% filename := "spacestation2.raw"
open : input, filename, get
var count : int := 1
put "Reading File..."
loop
for i : 1 .. 3
get : input, shape (count).x (i)
get : input, shape (count).y (i)
get : input, shape (count).z (i)
end for
count += 1
exit when eof (input)
new shape, count
end loop
close : input
put upper (shape), " Polygons Read."

The answer is probably something very simple, and I'm missing it completely. I dug up some formulas for rotation, but I didn't understand them. Its from some computer science university class. Open with PPT.

I have to go,

-Z

RaPsCaLLioN · **Posted:** Sat Aug 21, 2004 7:58 am

This is the procedure for rotation. iTheta is the angle whether +/-. The big problem I encountered initially was during display. It took me forever to realize to use a temp variable to store the rounded value to display. I first rounded each stored point which caused distortion in shape.

code:

procedure Rotate (iAxisA, iAxisB, iTheta : int)

var iU, iV : real

for i : 1 .. iNumPolys
for j : 1 .. 3
iU := arPolygons (i, j, iAxisA)
iV := arPolygons (i, j, iAxisB)
arPolygons (i, j, iAxisA) := (iU * cosd (iTheta) + iV * sind (iTheta))
arPolygons (i, j, iAxisB) := (-iU * sind (iTheta) + iV * cosd (iTheta))
end for
end for

end Rotate

TheZsterBunny · **Posted:** Sat Aug 21, 2004 8:42 am

Crap. I've seen that thing before too.

This

code:

var tempx, tempy, tempz : array 1 .. 3 of int
for i : 1 .. upper (shape)
for j : 1 .. 3
tempx (j) := round (shape (i).x (j)) + xoffset
tempy (j) := round (shape (i).y (j)) + yoffset
tempz (j) := round (shape (i).z (j)) % + ???????
end for
drawpolygon (tempx, tempy, 3, black)
end for

is what I've used to draw my shapes.

Can you please explain to me what the iAxis variables are?

Thanks

-Z

--edit--

and what arPolygons are

--edit--

I get it. Thanks.

-Z

-Z

TheZsterBunny · **Posted:** Sat Aug 21, 2004 11:32 am

Ok, got it.

'cept I'm having trouble with the z-sort.

...and shapes with over 10 000 polygons.

meh.

-Z

code:

var dispx, dispy : array 1 .. 3 of int
type poly :
record
xyz : array 1 .. 3, 1 .. 3 of real
end record
var shape : flexible array 1 .. 1 of poly
var xoffset : int := maxx div 2
var yoffset : int := maxy div 2
var input : int
var filename : string
put "Enter File Name followed by .raw: " ..
get filename
assert length (filename) > 4 and filename (* -3 .. *) = ".raw" and File.Exists (filename)
open : input, filename, get
var count : int := 1
put "Reading File..."
loop
for i : 1 .. 3
get : input, shape (count).xyz (1, i)
get : input, shape (count).xyz (2, i)
get : input, shape (count).xyz (3, i)
end for
count += 1
exit when eof (input)
new shape, count
end loop
close : input
var unsort : array 1 .. upper (shape) of real
var sort : array 1 .. upper (shape), 1 .. 2 of real
var mx, my, mb : int
var yangle, xangle : int := 0
put upper (shape), " Polygons Read."
setscreen ("offscreenonly")
proc rotate (axis1, axis2, ang : int)
var iu, iv : real
for i : 1 .. upper (shape)
for j : 1 .. 3
iu := shape (i).xyz (axis1, j)
iv := shape (i).xyz (axis2, j)
shape (i).xyz (axis1, j) := (iu * cosd (ang) + iv * sind (ang))
shape (i).xyz (axis2, j) := (-iu * sind (ang) + iv * cosd (ang))
end for
end for
end rotate
proc draw (axis1, axis2 : int)
cls
for i : 1 .. upper (shape)
for j : 1 .. 3
dispx (j) := round (shape (i).xyz (axis1, j)) + xoffset
dispy (j) := round (shape (i).xyz (axis2, j)) + yoffset
end for
drawpolygon (dispx, dispy, 3, black)
end for
drawline (0, maxy div 2, maxx, maxy div 2, blue)
drawline (maxx div 2, 0, maxx div 2, maxy, red)
View.Update
end draw
var alicia : array char of boolean
loop
Input.KeyDown (alicia)
if alicia (KEY_LEFT_ARROW) and xoffset - 10 > 0 then
xoffset -= 10
end if
if alicia (KEY_RIGHT_ARROW) and xoffset + 10 < maxx then
xoffset += 10
end if
if alicia (KEY_UP_ARROW) and yoffset + 10 < maxy then
yoffset += 10
end if
if alicia (KEY_DOWN_ARROW) and yoffset - 10 > 0 then
yoffset -= 10
end if
mousewhere (mx, my, mb)
if mb = 1 then
if my > 0 and my < maxy then
yangle := round (((my + yoffset) div 2 / maxy) * (10)) - 5
else
yangle := 0
end if
if yangle not= 0 then
rotate (2, 3, yangle)
end if
if mx > 0 and mx < maxx then
xangle := round (((mx + xoffset) div 2 / maxx) * (10)) - 5
else
xangle := 0
end if
if xangle not= 0 then
rotate (1, 3, xangle)
end if
end if
if xangle not= 0 or yangle not= 0 then
draw (1, 2)
end if
end loop

RaPsCaLLioN · **Posted:** Sat Aug 21, 2004 7:42 pm

When I used ur code I didn't have problems with .raw files larger than 10k.. What's happening?

TheZsterBunny · **Posted:** Sun Aug 22, 2004 9:32 pm

No problems with polygon numbers, but it becomes a bit slow.

My Z-Sort is quite slow, and there are occasional problems with overlap.

-Z

TheZsterBunny · **Posted:** Sun Aug 22, 2004 9:58 pm

code:

var dispx, dispy : array 1 .. 3 of int
var colorthing : int := 12
type poly :
record
xyz : array 1 .. 3, 1 .. 3 of real
end record
var shape : flexible array 1 .. 1 of poly
var xoffset : int := maxx div 2
var yoffset : int := maxy div 2
var input : int
var filename : string
put "Enter File Name followed by .raw: " ..
get filename
assert length (filename) > 4 and filename (* -3 .. *) = ".raw" and File.Exists (filename)
open : input, filename, get
var count : int := 1
put "Reading File..."
loop
for i : 1 .. 3
get : input, shape (count).xyz (1, i)
get : input, shape (count).xyz (2, i)
get : input, shape (count).xyz (3, i)
end for
count += 1
exit when eof (input)
new shape, count
end loop
close : input
var unsort : array 1 .. upper (shape) of real
var sort : array 1 .. upper (shape), 1 .. 2 of real
var mx, my, mb : int
var yangle, xangle : int := 0
put upper (shape), " Polygons Read."
setscreen ("offscreenonly")
proc rotate (axis1, axis2, ang : int)
var iu, iv : real
for i : 1 .. upper (shape)
for j : 1 .. 3
iu := shape (i).xyz (axis1, j)
iv := shape (i).xyz (axis2, j)
shape (i).xyz (axis1, j) := (iu * cosd (ang) + iv * sind (ang))
shape (i).xyz (axis2, j) := (-iu * sind (ang) + iv * cosd (ang))
end for
end for
end rotate
proc draw (axis1, axis2 : int)
cls
drawline (0, maxy div 2, maxx, maxy div 2, blue)
drawline (maxx div 2, 0, maxx div 2, maxy, red)
for decreasing i : upper (shape) .. 1
for j : 1 .. 3
dispx (j) := round (shape (round (sort (i, 1))).xyz (axis1, j)) + xoffset
dispy (j) := round (shape (round (sort (i, 1))).xyz (axis2, j)) + yoffset
end for
colorthing := RGB.AddColor ((1 - (sort (i, 2) / 240)), (1 - (sort (i, 2) / 240)), (1 - (sort (i, 2) / 240)))
drawfillpolygon (dispx, dispy, 3, colorthing)
drawpolygon (dispx, dispy, 3, black)
end for
View.Update
end draw
proc zsort
for qiy : 1 .. upper (shape)
unsort (qiy) := (shape (qiy).xyz (3, 1) + shape (qiy).xyz (3, 2) + shape (qiy).xyz (3, 3)) / 3
for yiq : 1 .. 2
sort (qiy, yiq) := -999999
end for
end for
for zing : 1 .. upper (shape)
var templow : real := 999999
var whichlow : int
for zing2 : 1 .. upper (shape)
if unsort (zing2) < templow then
templow := unsort (zing2)
whichlow := zing2
end if
end for
sort (zing, 1) := whichlow
sort (zing, 2) := templow
unsort (round (whichlow)) := 99999
end for
end zsort
var alicia : array char of boolean
loop
Input.KeyDown (alicia)
if alicia (KEY_LEFT_ARROW) and xoffset - 10 > 0 then
xoffset -= 10
end if
if alicia (KEY_RIGHT_ARROW) and xoffset + 10 < maxx then
xoffset += 10
end if
if alicia (KEY_UP_ARROW) and yoffset + 10 < maxy then
yoffset += 10
end if
if alicia (KEY_DOWN_ARROW) and yoffset - 10 > 0 then
yoffset -= 10
end if
mousewhere (mx, my, mb)
if mb = 1 then
if my > 0 and my < maxy then
yangle := round ((my / maxy) * (10)) - 5
else
yangle := 0
end if
if yangle not= 0 then
rotate (2, 3, yangle)
end if
if mx > 0 and mx < maxx then
xangle := round ((mx / maxx) * (10)) - 5
else
xangle := 0
end if
if xangle not= 0 then
rotate (1, 3, xangle)
end if
end if
if xangle not= 0 or yangle not= 0 then
zsort
draw (1, 2)
end if
end loop

Tried my hand at the Z-Sort and distance shading parts of the engine. Still having trouble with both.

Fair warning with this version. THe fewer polygons, the better. I've tested this with plane2.raw and it has been pretty smooth.

Except for the overlapping polygons.

-Z

RaPsCaLLioN · **Posted:** Mon Aug 23, 2004 11:37 am

I'll check that code out when I get home and Edit this reply with comments.

EDIT
I see what u mean with the z-sort. Look into a Quick sort method. I can help u there if u need it. Also, try culling your polygons and that should fix some of the display problems. That should also speed up the system quite a bit.

I never liked distance shading. Confused

TheZsterBunny · **Posted:** Tue Aug 24, 2004 5:50 pm

Thanks.

I've spent the last 2 days trying to remember what I learned in compsci class. the teacher showed us an incredible sorting procedure which sorted huge arrays almost instantly, but I cannot remember it.

Also, what is the polygon culling?

--edit--

well I found your qsort procedures and am trying to decipher them.

I'm just curious as to one part. The variables 'lo' and 'hi', are they the actual values or the unsorted positions of?

-Z

RaPsCaLLioN · **Posted:** Wed Aug 25, 2004 9:50 am

'lo' and 'hi' are the array positions of the section to sort.
Polygon culling is removing background polygons (which aren't seen anyway) from being drawn to speed up the process.

TheZsterBunny · **Posted:** Wed Aug 25, 2004 3:10 pm

so to sort the entire array

code:

var unsort : array 1..5 of int

1 would be 'lo' and 5 would be 'hi'?

There is also palce for 2 arrays. A is the output, B is the unsorted data?

-Z

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