Problems w\Transparency when alpha blendin
Author
Hi everyone, First time poster, long time lurker...
I am just getting my feet wet with Dx8 and have come across this problem. I can get textures to be transparent fine and translucent fine however if I try to get them to be both, I wind up with my transparent color showing as black.
My render code looks like this, it is very straight foward (it seems anyway). Am I missing something in order to get both transparency and the second texture to be translucent?
D3DDevice.BeginScene
'' Draw first primative with no effects
D3DDevice.SetTexture 0, TextureLand
D3DDevice.DrawPrimitiveUP D3DPT_TRIANGLESTRIP, 2, TriStrip1(0), Len(TriStrip1(0))
'' Draw the second primative overlaying the first with transparency
D3DDevice.SetTexture 0, TextureWater
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAOP, D3DTOP_MODULATE
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG1, D3DTA_DIFFUSE
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG2, D3DTA_CURRENT
D3DDevice.SetRenderState D3DRS_SRCBLEND, D3DBLEND_SRCALPHA
D3DDevice.SetRenderState D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA
D3DDevice.SetRenderState D3DRS_ALPHABLENDENABLE, 1
D3DDevice.DrawPrimitiveUP D3DPT_TRIANGLESTRIP, 2, TriStrip(0), Len(TriStrip(0))
D3DDevice.SetRenderState D3DRS_ALPHABLENDENABLE, 0
D3DDevice.EndScene
Thanks in advance.
a couple things to try:
firstly:
if you have the zbuffer turned on then it won''t draw the same primitive over the top of itself since the pixels will fail the ztest.
secondly:
you can achieve this effect using multitexturing. see the SDK docs for info on this but basically you can set 2 textures at once and blend them together.
thirdly:
a screenshot would be helpful as well in determining whats actually going on. textual descriptions are always difficult
good luck,
Toby
Gobsmacked - by Toby Murray
firstly:
if you have the zbuffer turned on then it won''t draw the same primitive over the top of itself since the pixels will fail the ztest.
secondly:
you can achieve this effect using multitexturing. see the SDK docs for info on this but basically you can set 2 textures at once and blend them together.
thirdly:
a screenshot would be helpful as well in determining whats actually going on. textual descriptions are always difficult
good luck,
Toby
Gobsmacked - by Toby Murray
D3DDevice.SetTexture 0, TextureWater
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAOP, D3DTOP_MODULATE
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG1, D3DTA_DIFFUSE
D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG2, D3DTA_CURRENT
I think ARG2 is supposed to be D3DTA_TEXTURE. If you''re not using lighting, then CURRENT == DIFFUSE.
Stay Casual,
Ken
Drunken Hyena
Author
Thanks, Toby and Ken. I was finally able to figure it out: Ken, your D3DTA_TEXTURE hint was right on the money. The solution looks like this:
BTW I would like to post a picture of the results. I have seen others do so, can I do this? I read the FAQ but couldn't find anything on it.
Again, thanks for your time guys.
- Sir Code Alot
[edited by - sir code alot on September 12, 2002 1:15:37 AM]
D3DDevice.BeginScene D3DDevice.SetRenderState D3DRS_SRCBLEND, D3DBLEND_SRCALPHA D3DDevice.SetRenderState D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA D3DDevice.SetRenderState D3DRS_ALPHABLENDENABLE, 1 ' Draw first primative with no effects D3DDevice.SetTexture 0, TextureLand D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAOP, D3DTOP_MODULATE D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG1, D3DTA_DIFFUSE D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG2, D3DTA_TEXTURE ' TriStrip1 has all its vertex alpha's set to 1 D3DDevice.DrawPrimitiveUP D3DPT_TRIANGLESTRIP, 2, TriStrip1(0), Len(TriStrip1(0)) ' Draw the second primative overlaying the first with transparency D3DDevice.SetTexture 0, TextureWater D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAOP, D3DTOP_MODULATE D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG1, D3DTA_DIFFUSE D3DDevice.SetTextureStageState 0, D3DTSS_ALPHAARG2, D3DTA_TEXTURE D3DDevice.DrawPrimitiveUP D3DPT_TRIANGLESTRIP, 2, TriStrip(0), Len(TriStrip(0)) D3DDevice.SetRenderState D3DRS_ALPHABLENDENABLE, 0D3DDevice.EndScene BTW I would like to post a picture of the results. I have seen others do so, can I do this? I read the FAQ but couldn't find anything on it.
Again, thanks for your time guys.
- Sir Code Alot
[edited by - sir code alot on September 12, 2002 1:15:37 AM]
This topic is closed to new replies.
Advertisement
Popular Topics
Advertisement
