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9
votes
2answers
2k views

Why are some games using some dithering pattern instead of traditional alpha for transparency?

Recently, I have seen some 3D games (eg: GTA IV) to use some kind of ordered dithering to simulate transparency / alpha. The polygons are not transparent as usual, but instead render a dithering ...
4
votes
1answer
228 views

Premultiplied Alpha And Alpha Testing

I have a shader that is supposed to work with either alpha blending or alpha testing, but the color values being passed in are premultiplied alpha values. Is there an easy/standard way to have it ...
4
votes
2answers
1k views

Pygame set_colorkey transparency issues

I'm having a strange issue that I cannot seem to remedy. I am doing some prototyping with Pygame on a desktop running windows and a laptop running OS X. Both are running python v2.7.3 (installed via ...
4
votes
2answers
140 views

XNA Transparency depending on drawing order?

I am drawing two 3D objects, both of them can fade from opaque to transparent independently, and they can intersect between them (so you cannot say when one of them is before the other one). Look at ...
3
votes
2answers
3k views

Android: Loading bitmaps without premultiplied alpha (OpenGL ES 2.0)

Is this possible? To load textures in non-premultiplied format (Straight alpha?)? My game has 1 or 2 images which have semi-transparent pixels and I need to be able to fade them in and out but this ...
3
votes
1answer
326 views

Odd blending result (semi-transparent 2d quad over 3D scene)

I'm working on a GUI library for my game, and I'm having problems with my blending. I have a 3D scene, which I render with glDrawArrays. In the fragment shader the alpha color is hardcoded 1.0f ...
3
votes
1answer
417 views

XNA 4.0 - Why does using a RenderTarget2d cause transparency on models?

I have been working through Riemers ShadowMap tutorial and everything was going well until the section on drawing to a separate rendertarget. I am using a different model and quads but I assumed the ...
2
votes
0answers
26 views

Render on texture with alpha 0 for the background colour

Sorry if the question is stupid but I am very new to opengl. I render on a target a scene with a couple of object on a background that is nothing more than the clear colour (which is ...
2
votes
2answers
189 views

XNA hlsl tex2D() only reads 3 channels from normal maps and specular maps

Our engine uses deferred rendering and at the main draw phase gathers plenty of data from the objects it draws. In order to save on tex2D calls, we packed our objects' specular maps with all sorts of ...
1
vote
1answer
36 views

Give alpha to an object OpenGL ES

I am new on OpenGl and what I want to achieve is to give a texture the alpha from 1.0 to 0.0 I have been searching and only found "how to load alpha in images" but I cant find how to apply alpha to ...
1
vote
0answers
23 views

XNA 4.0 - Model texture transparency [closed]

I'm trying to use a semi transparent texture on a model in xna using BasicEffect, like this: ((BasicEffect)mesh.Effects[0]).Texture = alphaTexture; I've made the texture in code using color class, ...
1
vote
0answers
109 views

How to put OpenGL in a state for drawing blended, colored, nontextured polys?

Using OpenGL1.1 (sadly) I'm trying to draw a cube, which is colored and alpha blended. It is instead showing up as opaque black. Even without including alpha in the color it still shows up as opaque ...
0
votes
1answer
27 views

Get color array with alpha for an image in java

I can get the pixel array like this: int[] pixels = image.getRGB(0, 0, width, height, null, 0, width); But it ignores the alpha channel, I only get the rgb (I'm reading a PNG image). How can I get ...
0
votes
1answer
65 views

Blending issue with framebuffer

I'm trying to get some particles to work properly - they should blend among themselves but not with the background color. For this I'm using additive blending, textures with premultipled alpha and set ...
0
votes
1answer
57 views

How can I load a picture with alpha channel in JME?

This code loads a picture into the game: Picture mypic= new Picture("mypic"); Texture2D tex = (Texture2D) assetManager.loadTexture("Textures/mypic.png"); ...
0
votes
1answer
251 views

Set alpha cutoff value Unity3d

I am continuing my previous question( link ). Now its working as per this demo. and the coding written to set cutoff is here : function Update () { renderer.material.SetFloat("_Cutoff", ...
0
votes
1answer
158 views

Why do the ALPHA channel in TGA is not visible?

Good morning GDSE, I am loading a TGA using loadTGA function found in superbible 4th edition source code. Here is how the image looks in Gimp You can see I have enabled alpha channel in Gimp, I ...
0
votes
1answer
338 views

Incorrect colour blending when using a pixel shader with XNA

I'm using XNA 4.0 to create a 2D game and while implementing a layer tinting pixel shader I noticed that when the texture's alpha value is anything between 1 or 0 the end result is different than ...
0
votes
0answers
39 views

OpenGL ES respecting alpha for background but not for objects

I have a problem with the alpha of my game, maybe it is solved in another post but as I am new in OpenGl and Game developemnt I dont understand most of the vocabulary and cant find a solution. The ...
0
votes
0answers
23 views

Maya physical sun and sky rendering as alpha

Im trying to render a animation but the sky is saved as an alpha. it shows up in the render window, but when i look at the files there alpha channels so when i put it into final cut to create a video ...
0
votes
0answers
46 views

OpenGL - How to use depth checking and alpha blending at the same time? [duplicate]

Suppose I have a semi-transparent object (let's call this "bubble"), a solid object (let's call this "wall"), and the bubble is closer to the camera compared to the wall behind it. If I draw the ...
0
votes
1answer
835 views

Alpha Value at 0 Shows Black for Android Canvas Bitmap

There have been a few questions similar to this but none seem to give a straight answer. If I am creating a Bitmap from a .png image and want to set a color (i.e. true pink) to transparent, the color ...
-1
votes
1answer
132 views

Slick2D ingoring aplha channel?

When I use the draw method inside a image, it completely ingores the alpha channel and fills it in with white. Is there a way I can draw it where the alpha is see through like it's suppost to be? I ...
-1
votes
1answer
184 views

XNA changing color alpha

I know I can take a color and multiply it by a float to reduce its alpha like that: Color color = Color.Green * 0.15f; But how do I return the color's alpha to it's original value? I tried doing ...