Direct3D 10

Re: How to alpha blend sprites?

TordinBjorn — Sat, 11 Jul 2009 22:09:56 GMT

it dosent know how to render the alpha pixel, wich means, render it black or render it with the thing it is overlapping.

Re: How to alpha blend sprites?

nick85 — Sat, 11 Jul 2009 21:21:35 GMT

Why would you not have the alpha blend state set?

Re: How to alpha blend sprites?

TordinBjorn — Sat, 11 Jul 2009 15:22:42 GMT

that dosen't work if you haven't set the alpha blend state, since it still dosent know how to handle the alpha

Re: How to alpha blend sprites?

nick85 — Sat, 11 Jul 2009 14:54:25 GMT

Dude this is toatally simple. Just save it as a .png. It stores transparency.

Re: How to alpha blend sprites?

TordinBjorn — Sat, 11 Jul 2009 10:31:48 GMT

you have to set the blendsource desc, like this and it will work. becaus you can't just tell dx10 to use alpha when it dosent know how to blend it!

ID3D10BlendState* g_pBlendStateNoBlend = NULL;

D3D10_BLEND_DESC BlendState;
ZeroMemory(&BlendState, sizeof(D3D10_BLEND_DESC));
BlendState.BlendEnable[0] = true;
BlendState.RenderTargetWriteMask[0] = D3D10_COLOR_WRITE_ENABLE_ALL;
BlendState.SrcBlend = D3D10_BLEND_SRC_ALPHA;
BlendState.DestBlend = D3D10_BLEND_INV_SRC_ALPHA;
BlendState.BlendOp = D3D10_BLEND_OP_ADD;
BlendState.SrcBlendAlpha = D3D10_BLEND_ZERO;
BlendState.DestBlendAlpha = D3D10_BLEND_ZERO;
BlendState.BlendOpAlpha = D3D10_BLEND_OP_ADD;
BlendState.AlphaToCoverageEnable = true;
g_pd3dDevice->CreateBlendState(&BlendState, &g_pBlendStateNoBlend);
float blendFactor[] = {0,0,0,0};
UINT sampleMask   = 0xffffffff;

g_pd3dDevice->OMSetBlendState(g_pBlendStateNoBlend, blendFactor, sampleMask);

i hope this helps!

Re: How to alpha blend sprites?

Craig Martin — Fri, 26 Jun 2009 12:19:23 GMT

Captain G:
That didn't seem to work, no matter where I put it.

My textures are currently embedded into the .FBX files exported from 3ds max, though eventually I'd like to have the textures be coupled to the models in the code so that I can use the same texture on different models to save on memory.

I'm sure it's apparent by now that I'm a noob at this, but any help anyone can offer is appreciated.

Are you using BasicEffect to render your models? If so have you set the Alpha property on the mesh effect to some value less than 1.0f?

Maybe also try these settings:

                graphicsDevice.RenderState.AlphaBlendEnable = true;
               graphicsDevice.RenderState.AlphaBlendOperation = BlendFunction.Add;
               graphicsDevice.RenderState.SourceBlend = Blend.SourceAlpha;
               graphicsDevice.RenderState.DestinationBlend = Blend.DestinationAlpha;
               graphicsDevice.RenderState.SeparateAlphaBlendEnabled = false;

also try this (rather than Blend.DestinationAlpha):

                graphicsDevice.RenderState.DestinationBlend = Blend.InverseSourceAlpha;

Re: How to alpha blend sprites?

Captain G — Fri, 26 Jun 2009 04:58:51 GMT

That didn't seem to work, no matter where I put it.

My textures are currently embedded into the .FBX files exported from 3ds max, though eventually I'd like to have the textures be coupled to the models in the code so that I can use the same texture on different models to save on memory.

I'm sure it's apparent by now that I'm a noob at this, but any help anyone can offer is appreciated.

Re: How to alpha blend sprites?

Craig Martin — Sun, 14 Jun 2009 02:21:40 GMT

Captain G:
I also am having a little confusion with alphas. I'm placing simple 3D geometry in the world and moving it around. I don't have any screen HUD things, yet I still need to do a spriteBatch.Begin() and End() in order for my 3D objects' alpha to work. I have nothing between the Begin() and End(), yet it still seems to do make the alphas work. Is there a setting I can change so I don't even need the sprite batch?

GraphicsDevice.RenderState.AlphaBlendEnable = true;

Re: How to alpha blend sprites?

Captain G — Sun, 14 Jun 2009 00:25:12 GMT

I also am having a little confusion with alphas. I'm placing simple 3D geometry in the world and moving it around. I don't have any screen HUD things, yet I still need to do a spriteBatch.Begin() and End() in order for my 3D objects' alpha to work. I have nothing between the Begin() and End(), yet it still seems to do make the alphas work. Is there a setting I can change so I don't even need the sprite batch?

Re: How to alpha blend sprites?

George Clingerman — Sun, 07 Dec 2008 18:36:48 GMT

What exactly are you trying to do? If you're using the sprite batch AlphaBlend is turn on by default (or you can explicitly set it if you want like this -> spriteBatch.Begin(SpriteBlendMode.AlphaBlend);).

Is there something that's not working for you? If you could describe in a little more detail what you're trying to achieve I'm sure we can get you pointed in the right direction.

How to alpha blend sprites?

Unholysavagery — Wed, 03 Dec 2008 19:09:59 GMT

I need to draw a sprite with alpha but I don't know how and I Googled it and found little if any useful information.