SOLVED Sprite in 3D wont show whats behind

[Kahrabaa]

Hi.

In a 3D space, Im drawing 3 sprites with different y coordinates to place them in front of each other. The problem is the front sprite covers the back sprites even in areas that are transparent on that sprite.

Left pic is without shader. Right pic with new default shader

This only happens when I draw the sprites through a shader. (New unchanged shader)

shader_set(shader0);
    matrix_set(matrix_world,matrix_build(0,0,0,60,0,0,1,1,1));
    draw_sprite_ext(sprite_index,image_index,0,0,1,1,image_angle,image_blend,image_alpha); //Sprite 1

    matrix_set(matrix_world,matrix_build(24,-1,0,60,0,0,1,1,1)); //Shift y up a pixel
    draw_sprite_ext(sprite_index,image_index,0,0,1,1,image_angle,image_blend,image_alpha); //Sprite 2

    matrix_set(matrix_world,matrix_build(48,-2,0,60,0,0,1,1,1)); //Shift y up another pixel
    draw_sprite_ext(sprite_index,image_index,0,0,1,1,image_angle,image_blend,image_alpha); //Sprite 3
    shader_reset();

Noticed that if i invert the drawing order then the problems goes away by swapping the code for sprite 3 with sprite 1

It should draw correctly no matter the order since game objects will move around. I am trying to avoid adding all objects to a ds list to sort them then draw..
What am I doing wrong?

Spoiler: 3d Init

gpu_set_alphatestenable(1);
gpu_set_ztestenable(1);
gpu_set_zwriteenable(1);
gpu_set_cullmode(cull_noculling);

Spoiler: Camera draw

var camera=camera_get_active();
camera_set_view_mat(camera,matrix_build_lookat(x+cam3dx,y+cam3dy+250,cam3dz+500,x+cam3dx,y+cam3dy,0,0,1,0));
camera_set_proj_mat(camera,matrix_build_projection_perspective_fov(60,window_get_width()/window_get_height(),1,32000));
camera_apply(camera);

Thanks for your time

 

[Joe Ellis]

It's cus the alpha test reference value is too low (or zero), so it doesn't discard any of the 0% alpha pixels.
You should just need to set it to something higher than zero:

gpu_set_alphatestref(0.1)

 

[Kahrabaa]

Frogot to write that I tried that already :/
Tried .1, .9 no difference.

 

[sp202]

You need to manually discard fragments in the shader.

if (tex.a == 0.) {
 discard;
}

 

[Joe Ellis]

You need to manually discard fragments in the shader.

if (tex.a == 0.) {
discard;
}

I was going to suggest that but for reason I thought I remembered the ref value affecting all drawing, like alphablend or culling. Sorry :/

 

[Kahrabaa]

Wonderful

Thanks alot !