SET ALPHA MAPPING ON doesn't work on blend mapped objects.

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Ric

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Posted: 31st Aug 2005 13:05 Edited at: 31st Aug 2005 13:08

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Not only does the alpha mapping not seem to work on blen mapped objects, but using the command causes the blend mapped object to lose its transparency too. I've written this test code to demonstrate the problem:

+ Code Snippet

text 0,0, "make black and white checked texture"
box 20,20,70,70
box 70,70,120,120
get image 1,20,20,120,120,1
wait 3000

cls
text 0,0, "make red texture"
ink rgb(255,0,0),0
box 20,20,120,120
get image 2,20,20,120,120,1
wait 3000

sync on
make object plain 1,1,1
sync
text 0,0, "make plane"
sync
wait 3000

texture object 1,1
sync
text 0,0, "texture it with the black and white checked pattern"
sync
wait 3000

set blend mapping on 1,2,5
sync
text 0,0, "blend the texture with the red texture"
sync
wait 3000

set object transparency 1,1
sync
text 0,0, "make the object transparent"
sync
wait 3000

set alpha mapping on 1,50
sync
text 0,0, "set alpha mapping on"
text 0,20," - uhoh, it didn't work, and it lost its transparency."
sync
wait key

If you rem out the 'set blend mapping on' line, though, then the alpha mapping works as expected. If anyone knows of any work arounds, it would be most useful!

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RiiDii

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Posted: 10th Sep 2005 23:17 Edited at: 10th Sep 2005 23:17

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Ric, here's a stab at it. The alpha mapping isn't working yet, but the transperancy sticks around. I was just playing with the numbers and the way things were ordered (which seems to make a difference with Direct X).

+ Code Snippet

Autocam Off
text 0,0, "make black and white checked texture"
box 20,20,70,70
box 70,70,120,120
get image 1,20,20,120,120,1
wait 1000

cls
text 0,0, "make red texture"
ink rgb(255,0,0),0
box 20,20,120,120
get image 2,20,20,120,120,1
wait 1000

sync on
position camera 0,0,-5
make Object Sphere 2,1
Position Object 2,0,0,.7
make object plain 1,1,1
Position Object 1,0,0,0
sync
text 0,0, "make plane"
sync
wait 1000

texture object 1,2
sync
text 0,0, "texture it with the black and white checked pattern"
sync
wait 1000

set blend mapping on 1,1,5
sync
text 0,0, "blend the texture with the red texture"
sync
wait 1000

set object transparency 1,5
sync
text 0,0, "make the object transparent"
sync
wait 1000

set alpha mapping on 1,50
sync
text 0,0, "set alpha mapping on"
text 0,20," - uhoh, it didn't work, and it lost its transparency."
sync


wait key

Open MMORPG: It's your game!

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Ric

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Location: object position x

Posted: 10th Sep 2005 23:39

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Thanks Rii - almost forgot about this thread! I think I actually have a successful workaround to this now using a memblock function written by ..... hmmm, can't remeber. Can't remember where I put the function either. I'm getting old. I'll post the function and the credit here as soon as I find it!

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Zealous

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Posted: 11th Sep 2005 05:49

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Hey im wrestling with another bug right now with alpha mapping instanced objects. it seems as soon as you set alpha mapping on a instanced object all transparency is lost, and there is no way to get it back (set shading off, set object transparency, nothing). Once you alpha map it, you are hosed.

Is there a fix for this too?

All you need is zeal

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Ric

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Location: object position x

Posted: 11th Sep 2005 13:29

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@Zealous: Here's the function I'm now using for alphamapping, courtesy of Lost in Thought:

+ Code Snippet

function opacity(inputimage,outputimage,value)

alphamemblock=1
make memblock from image alphamemblock,inputimage

wide = memblock dword(alphamemblock,0)
high = memblock dword(alphamemblock,4)
deep = memblock dword(alphamemblock,8)
location = 12
for i = 1 to wide
   for j = 1 to high
      write memblock byte alphamemblock,(location+3),value
      inc location, 4
   next j
next i

make image from memblock outputimage,alphamemblock
delete memblock alphamemblock

endfunction

The value is out of one hundred. See if that solves the problem you're having.

And the function I'm using to blend two images is:

function blend_image(image1,image2,newimage,p#,threshold#)

if p#>1 then p#=1

memd=free_memblock():make memblock from image memd,image1
   memf=free_memblock():make memblock from image memf,image2
   mems=free_memblock():make memblock mems,get memblock size(memd)

sx=memblock dword(memd,0):sy=memblock dword(memd,4)
   write memblock dword mems,0,sx:write memblock dword mems,4,sy:write memblock dword mems,8,32

for x=0 to sx-1
      for y=0 to sy-1

pos=(y*sx+x)*4
         b1=memblock byte(memd,pos+12):g1=memblock byte(memd,pos+13):r1=memblock byte(memd,pos+14):a1=memblock byte(memd,pos+15)
         b2=memblock byte(memf,pos+12):g2=memblock byte(memf,pos+13):r2=memblock byte(memf,pos+14):a2=memblock byte(memf,pos+15)
if (r1+g1+b1)/3.0>threshold#
         r=( r1*p# + r2*(1-p#) )
         g=( g1*p# + g2*(1-p#) )
         b=( b1*p# + b2*(1-p#) )
         a=( a1*p# + a2*(1-p#) )
else
         r=r1
         g=g1
         b=b1
         a=a1
endif
         write memblock byte mems,pos+12,b:write memblock byte mems,pos+13,g:write memblock byte mems,pos+14,r:write memblock byte mems,pos+15,a
      next y
   next x
   make image from memblock newimage,mems : delete memblock mems : delete memblock memd : delete memblock memf

endfunction

function free_memblock()
   for m=1 to 255
      if memblock exist(m)=0 then exitfunction m
   next m
endfunction 0

+ Code Snippet

function blend_image(image1,image2,newimage,p#,threshold#)

if p#>1 then p#=1

   memd=free_memblock():make memblock from image memd,image1
   memf=free_memblock():make memblock from image memf,image2
   mems=free_memblock():make memblock mems,get memblock size(memd)

   sx=memblock dword(memd,0):sy=memblock dword(memd,4)
   write memblock dword mems,0,sx:write memblock dword mems,4,sy:write memblock dword mems,8,32

   for x=0 to sx-1
      for y=0 to sy-1

         pos=(y*sx+x)*4
         b1=memblock byte(memd,pos+12):g1=memblock byte(memd,pos+13):r1=memblock byte(memd,pos+14):a1=memblock byte(memd,pos+15)
         b2=memblock byte(memf,pos+12):g2=memblock byte(memf,pos+13):r2=memblock byte(memf,pos+14):a2=memblock byte(memf,pos+15)
if (r1+g1+b1)/3.0>threshold#
         r=( r1*p# + r2*(1-p#) )
         g=( g1*p# + g2*(1-p#) )
         b=( b1*p# + b2*(1-p#) )
         a=( a1*p# + a2*(1-p#) )
else
         r=r1
         g=g1
         b=b1
         a=a1
endif
         write memblock byte mems,pos+12,b:write memblock byte mems,pos+13,g:write memblock byte mems,pos+14,r:write memblock byte mems,pos+15,a
      next y
   next x
   make image from memblock newimage,mems : delete memblock mems : delete memblock memd : delete memblock memf

endfunction

function free_memblock()
   for m=1 to 255
      if memblock exist(m)=0 then exitfunction m
   next m
endfunction 0

which is based on code by Math89, where p# is a value between 0 and 1 and determines the proportion of each image image that gets blended (ie 0.5 will blend half of each, 0.25 will blend a quarter of one and three quarters of the other) and threshold# is a value between 0 and 255 and determines the minimum colour value of the original image which is affected by blending (ie. a value of 20 will mean all colour values below 20 in the original image will remain unchanged, and all colour values above 20 will get blended with the new image)

Make sure blended images are of equal size. Works with the opacity function above.

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Zealous

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Posted: 12th Sep 2005 00:53

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Nooooo I cant muck with the image, as I am working with instanced objects (they all share the same image, but need to alpha in and out individually).

Please tell me there is another way!

All you need is zeal

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Ric

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Posted: 12th Sep 2005 01:42

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When you say you lose all transparency - is it still transluscent or completely opaque? And what flag for transparency are you using?

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Zealous

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Posted: 12th Sep 2005 02:11

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Im using flag 2. When I say it loses all transparency, I mean it goes back to a solid image (where there once was alpha, there is now solid white). Its like a instanced objects cant have transpaerent spots on its image, AND be alpha mapped at the same time.

All you need is zeal

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Ric

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Posted: 12th Sep 2005 02:52

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What if you set ghosting on as well? I once used transparency (flag 5), ghost (5) and alpha mapping on all together to get the right effect.

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Zealous

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Posted: 12th Sep 2005 03:55

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oh I can alpha map a object with transparency flag 2, but not a instanced objects. Ill try ghosting when I get home but I have a feeling it wont work (even if it does, ghosting wont help, i need to fade it in from nothing to solid).

All you need is zeal

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Mike Johnson

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Posted: 1st Oct 2005 22:40

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The current code uses "set blend mapping on 1,2,5" and this sets blend mapping on for object 1 and uses cube mapping data for the texture coordinates ( specified by the parameter 2 ) and then last of all modulate2x is set with the parameter 5.

Try changing this so the UV coordinates are taken from the plane object. Use 0 for the 2nd parameter e.g. set blend mapping on 1, 0, 5. Now you can get to see alpha mapping working in conjunction with the blend mapping.

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Ric

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Posted: 2nd Oct 2005 12:02

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I'm confused - according to the help file, the second parameter is the image number. So setting blend mapping on with 1,0,5 presumably tries to blend with image 0, which doesn't exist - no? In any event, it still doesn't work for me - if you care to check:

+ Code Snippet

 text 0,0, "make black and white checked texture"
box 20,20,70,70
box 70,70,120,120
get image 1,20,20,120,120,1
wait 3000

cls
text 0,0, "make red texture"
ink rgb(255,0,0),0
box 20,20,120,120
get image 2,20,20,120,120,1
wait 3000

sync on
make object plain 1,1,1
sync
text 0,0, "make plane"
sync
wait 3000

texture object 1,1
sync
text 0,0, "texture it with the black and white checked pattern"
sync
wait 3000

set blend mapping on 1,0,5
sync
text 0,0, "blend the texture with the red texture"
sync
wait 3000

set object transparency 1,1
sync
text 0,0, "make the object transparent"
sync
wait 3000

set alpha mapping on 1,50
sync
text 0,0, "set alpha mapping on"
text 0,20," - uhoh, it didn't work, and it lost its transparency."
sync
wait key

However, reading around the forums a bit, I discover that there are actually 5 parameters now: object,stage,image,texturecoordmode,blendmode. I've tried using this format by putting various different numbers in, but as I can't find any information on what the various modes mean/do, I'm rather lost.

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jrowe

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Posted: 2nd Oct 2005 12:27 Edited at: 2nd Oct 2005 12:51

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Ric: An explanation of the new blendmapping parameters can be found in Jessticular's Helpfiles:

http://jessticular.dbspot.com/index.php?nav=dbhelp&command=149

Perhaps, If you find a workaround for the alpha issue you can post it there too?

EDIT: The 5.8 example pack is good as it gives examples of all the new commands, worth a download.

Tinnedhead Productions
For Fathers and Sons who enjoy wholy spirits.

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Ric

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Posted: 2nd Oct 2005 12:39

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Thanks for that Jrowe - I'll look into it.

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Zealous

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Posted: 9th Oct 2005 09:04 Edited at: 9th Oct 2005 10:30

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Hmm something still isnt right. Check out my source. It seems if you apply blendmapping to any stage but 0, alpha mapping flips out and stops working.

In my terrain, I use uv stage 0 for a base color map, and uv stage 1 for a detail map. And because of that, alpha mapping wont work. Why should it matter how many times you blend, or to what stages? Why does alpha mapping care?

See source for a example

All you need is zeal

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Zealous

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Posted: 10th Oct 2005 00:47

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Please unreject this for bug week

or explain why alpha mapping cares if you use blend mapping on stages other than 0

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Mike Johnson

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Posted: 10th Oct 2005 12:41

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Zealous - the alpha factor is always dealt with as the last texture stage. To get your code working set a blend mapping mode for stage 2 - set blend mapping on 1,2,0,10,2. Your alpha is now applied last and things look like they should.

Here is the modified code -

+ Code Snippet

sync on: sync rate 60

make object plain 1,10,10: color object 1,rgb(50,255,75)
load image "detail.jpg",1

set blend mapping on 1,1,1,10,26
set blend mapping on 1,2,0,10,2

do
   set cursor 0,0
   print "What the..."

   inc alpha: if alpha > 100 then alpha = 0
   set alpha mapping on 1,alpha

   sync
loop

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Zealous

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Posted: 11th Oct 2005 00:38 Edited at: 11th Oct 2005 00:40

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Well your code works, however, when I set the sync rate to 0, the object flickers in and out. Can anyone else confirm? ONLY when I set sync rate to 60 does it fade in liek it should...

Does it have something to do with the fact youre using a image 0?

*Edit Duh, ignore that. Dang I didnt think the thing would be running at light speed. Was just moving very fast ehe im teh newb

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Bug Reports / SET ALPHA MAPPING ON doesn't work on blend mapped objects.

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