My opengl shader not working since latest revisions

I have written my own shader that composites 2 textures together using an alpha channel with some internal ramping/adjusting of the alpha values.

SInce the new revisions from alpha 3, it’s playing havoc with me.

This is my setup,

I have 2 viewports rendering into their own framebuffers, I use the textures from these to map onto 2 quads rendered in ortho to composite for final rendering.

ViewPort view1 = renderManager.createMainView(“view 1”, cam);




//same for view 2

(both views have fog enabled also)

When I’m rendering my 2 quads together, the top quad has my shader which only renders the texture sent to it using a separate texture sent to it as the alpha channel. The first big problem is that the shader is stoping the top quad being rendered at all! , but instead rendering into the quad below - which doesn’t have the shader attached to it.

this my shader code

// zblend.j3md

MaterialDef My MaterialDef {

MaterialParameters {

Texture2D Alpha

Texture2D Tex


Technique {

VertexShader GLSL100: MatDefs/zblend.vert

FragmentShader GLSL100: MatDefs/zblend.frag

WorldParameters {





// zblend.vert

uniform mat4 g_WorldViewProjectionMatrix;

in vec4 inPosition;

in vec2 inTexCoord;

out vec2 texCoord;

void main(){

gl_Position = g_WorldViewProjectionMatrix * vec4(inPosition, 1.0);

texCoord = inTexCoord;


// zblend.frag

uniform sampler2D Alpha;

uniform sampler2D Tex;

varying vec2 texCoord;

const float mn=0.92;

const float mx=0.94;

void main(){

vec4 atex = texture2D( Alpha, texCoord.xy );

vec4 mtex = texture2D( Tex, texCoord.xy );

float val=atex.r;

float mul=1.0/(mx-mn);

float newval=val;


if (val>mx)




if (val<mn)




gl_FragColor = vec4(mtex.r,mtex.g,mtex.b,1.0-newval);


Like I said, it all worked okay before the latest revisions.


Do you have more than one light?

Could you try to undo the revision 6566 and see if it works?

I have a similar issue, maybe it’s the problem

I have no lights at all, all simpletextured materials (pre baked lit textures).

will try the revision now anyway.

erm sorry - how do I go about reverting to the previous version of this file?

actually - probably best I just write a new shader using one of the ones that already work as a starting point.