Manipulate Shader constant by script - Error "does not have any property"(SOLVED)

Questions
1

Hi !

I create a new shader and try to manipulate constants using a script.
Unfortunately, I got this error when I launch the project :
‘#sprite’ does not have any property called ‘mouse’

I must miss something but I can’t figure what.

Thanks for your help !

What I have done :

  1. copy files .fp, .vp, .material from materials/sprite in a new folder

  2. rename files

  3. open the new material and select new VP and FP files. Then add 3 new constants

    image
    image225×103 1.5 KB

  4. add simple FP code to test

varying mediump vec2 var_texcoord0;
uniform lowp sampler2D texture_sampler;
uniform lowp vec4 mouse;
void main()
{
vec2 mouse = vec2(mouse.x, mouse.y);
gl_FragColor = vec4(var_texcoord0.xy, 0.0, 1.0);
}

  1. created a new script

function init(self)
go.set(“#sprite”, “mouse”, vmath.vector4(150.0, 150.0, 0, 0))
end

  1. in the collection, add a new GameObject and attach a Sprite (id = sprite) and the Script
  2. change the Sprite Material’s property to attach the material file
2

You not use mouse in code. Compiler throw it away.

If you make something like this, is should work

gl_FragColor.x = mouse.x;
2 Likes
3

Thanks d954mas !

It was definitively something I didn’t know :slight_smile:

I am just starting writing shaders, so maybe my question is not revelant, but does this means that all constants must be used in the gl_FragColor ?

I try to make a flashlight effect, and I would like to use mouse coordinates only to check a distance.
Is there a solution to do this ?

varying mediump vec2 var_texcoord0;
uniform lowp sampler2D texture_sampler;

uniform lowp vec4 mouse;
uniform lowp vec4 radius;
uniform lowp vec4 light;

float Tween(float k, float t, float T, float S, float E)
{
float c = E - S;
return c * pow(t/T, k) + S;
}

void main()
{
vec4 color = vec4(0,0,0,0);
vec2 screen_coord = vec2(var_texcoord0.x, var_texcoord0.y);

lowp vec4 color_of_pixel = texture2D(texture_sampler, var_texcoord0.xy);

float dist = distance(vec2(mouse.x, mouse.y), screen_coord);

if (dist <= radius.x)
{
    float alpha = Tween(light.x, dist, radius.x, 1, 0);
    color = vec4(1,1,1,alpha);
}
else
{
    vec4 color = vec4(0,0,0,0);

}

gl_FragColor = color_of_pixel * color;

}

4

No:)
gl_FragColor must depend on that constant. You can use it on code, functions or some others way.
Your example should work)

2 Likes
5

Thank you d954mas, you save my day !