Affine Effect Shader
A cheap try at reproducing the Affine Effect of older consoles for 3D games.
Shader code
shader_type spatial;
render_mode unshaded, cull_disabled, depth_prepass_alpha;
uniform float affineRadius = 4.0;
uniform float affineIntensity = 400;
uniform sampler2D image : source_color, repeat_enable;
uniform vec2 uv_scale = vec2(1.0,1.0);
varying float vertex_force;
void vertex() {
vec3 vertex_world_pos = (MODEL_MATRIX*vec4(VERTEX,1.0f)).xyz;
float true_dist = distance(CAMERA_POSITION_WORLD, vertex_world_pos);
if (true_dist <= 0.001){
vertex_force = 1.0/affineIntensity*length(UV)+1.0;
}
else {
vertex_force = affineRadius/true_dist/affineIntensity*length(UV)+1.0;
}
}
void fragment() {
vec2 new_uv = UV;
if (uv_scale[0] > 0.0f || uv_scale[1] > 0.0f){
new_uv[0] *= uv_scale[0];
new_uv[1] *= uv_scale[1];
}
vec4 new_image;
new_image = texture( image, new_uv*vertex_force);
ALBEDO = new_image.rgb;
ALPHA = new_image.a;
}
