Interior mapping made for TouchDesigner in GLSL

interiorMapping.frag

// Example Vertex Shader

out v2f {
	flat int cameraIndex;
	vec3 p;
	vec4 pos;
	vec2 uv;
	mat3 tbn;
} oVert;

in vec4 T;

vec3 rand3(float co){
	return fract(sin(co * vec3(12.9898,78.233,43.2316)) * 43758.5453);
}

void main() 
{
	oVert.p = P;
	vec4 worldSpacePos = TDDeform(P);
	oVert.pos = worldSpacePos;
	
	vec3 texcoord = TDInstanceTexCoord(uv[0]);
	oVert.uv.st = texcoord.st;
	
	oVert.cameraIndex = TDCameraIndex();
	
	vec3 worldSpaceT = normalize(TDDeformNorm(T.xyz));
	vec3 worldSpaceN = normalize(TDDeformNorm(N));
	
	oVert.tbn = TDCreateTBNMatrix(worldSpaceN, worldSpaceT, T.w);
	
	gl_Position = TDWorldToProj(worldSpacePos);
}

interiorMapping.vert

uniform sampler2D mapTex;
uniform sampler2D wallOut;

uniform vec4 uTilingOffset;

in v2f {
	flat int cameraIndex;
	vec3 p;
	vec4 pos;
	vec2 uv;
	mat3 tbn;
} iVert;

out vec4 fragColor;

vec4 over(vec4 front, vec4 backv) {
	return mix(backv, front, front.a);
}

void main()
{
	TDCheckDiscard();
	vec4 color = vec4(1.0);
	
	vec3 viewVec = normalize(iVert.pos.xyz - uTDMats[iVert.cameraIndex].camInverse[3].xyz);
	
	vec3 uvw = iVert.p * uTilingOffset.xyx * 0.999 + uTilingOffset.zwz;
	viewVec *= uTilingOffset.xyx;
	vec3 roomUVW = fract(uvw);
	
	vec3 pos = roomUVW * 2.0 - 1.0;
	vec3 id = 1.0 / viewVec;
    vec3 k = abs(id) - pos * id;
    float kMin = min(min(k.x, k.y), k.z);
    pos += kMin * viewVec;
    pos = normalize(pos);
	
	color = texture(mapTex, TDCubeMapToEquirectangular(pos));
	color = over(texture(wallOut, iVert.uv), color);
	
	TDAlphaTest(color.a);
	fragColor = TDOutputSwizzle(color);
}