How to setup fixed size(screen space) billboards using glsl

Asked Jul 04 '17 at 10:15

Active Jul 04 '17 at 17:23

Viewed 600 times

I am trying to create billboard using three.js. I tried using THREE.Sprite however size of sprite changes with distance as I am using perspective projection. I tried to create a plane using custom shaderMaterial with custom shader.

Shader code for scaling billboard

 vec4 gl_Position = projectionMatrix * (modelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0) + vec4(position.x, position.y, 0.0, 0.0));'

same for non scaling billboard, which I am trying implement

float distance = length(modelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0)); 
vec4 newPosition = projectionMatrix * (modelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0) + vec4(position.x, position.y, 0.0, 0.0));
gl_Position= newPosition*distance;

Unfortunately there is no changes in the output. Its still scaled billboard. Any suggestion that might fix the problem?

edited Jul 04 '17 at 17:23

gman

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asked Jul 04 '17 at 10:15

user3804449

maybe [this SO answer](https://stackoverflow.com/a/42347761/4045502) will be helpful – prisoner849 Jul 04 '17 at 10:25
Thanks, I wanted object to be even remain unscaled on zooming also. Ideally it should be in the screen space. – user3804449 Jul 10 '17 at 12:32

How to setup fixed size(screen space) billboards using glsl

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