GPU Programming for Dome Projection

Short Description
GPU Programming for Dome Projection. Purpose: Dome projection requires a fisheye projector lens, … Instead, we are doing it in a single-pass GPU program. …

Website: web.engr.oregonstate.edu | Filesize: 130kb

Content
GPU Programming for Dome Projection
Purpose: Dome projection requires a fisheye projector lens, which necessarily distorts the image.
The trick is to pre-distort the image in the other direction during the rendering process so
that the projected image looks correct. This could be done in software or in multi-pass hardware,
but this is slow. Instead, we are doing it in a single-pass GPU program.
November 23, 2005
Mike Bailey
mjb@cs.oregonstate.edu
GLSL Shader Code
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Fluid flow visualization in a dome Mars panoramic display in a dome
const float PI = 3.14159265;
const float C1 = ??;
const float C2 = ??;
const float C3 = ??;
const float C4 = ??;
const float C5 = ??;
void
main( void )
{
float phi;
vec4 pos = gl_ModelViewMatrix * gl_Vertex;
float rxy = length( pos.xy );
if( rxy != 0.0 )
{
float phi = atan( rxy, -pos.z );
// float lens_radius = phi / (PI/2.);
float lens_radius = phi* (C1 + phi* (C2 + phi* (C3 + phi* (C4 +…