ofxAddons
OpenGL LightMapper for openFrameworks
README
GPU Lightmapper
A simple OpenGL ambient light baker for OpenFrameworks.About
ofxGPULightmapper combines different techniques to generate fast and smooth ambient shadows and textures.
Usage
``
c++ // instance ofxGPULightmapper ofxGPULightmapper lightmapper;
ofMesh mesh; // Mesh model ofNode node; // Model world transformation ofFbo lightmap; // Lightmap texture ofLight light; // Sun light
// set up lightmapper and pass scene draw function (geometry-only, no materials) function<void()> scene = bind(&ofApp::renderSceneGeometry, this); lightmapper.setup(scene, 10); // 10 direct + 10 indirect shadow passes (doubled internally)
// optional: tune shadow quality lightmapper.setShadowBias(0.003f); lightmapper.setShadowBiasSlope(2.0f, 0.2f); // glPolygonOffset(slope, units) for grazing angles lightmapper.setContactShadowFactor(0.005f);
// setup lightmap lightmapper.allocateFBO(lightmap);
// Bake scene light into the lightmap using geometry lightmapper.updateShadowMap(light, {0,0,0}, 0.5, 10, 0.01, 20); lightmapper.bake(mesh, lightmap, node, sampleCount);
// Draw geometry with baked light lightmap.getTextureReference().bind(); mesh.draw();
VBO Mesh, Triangle Packer and UV spaces
The library can work both with ofMesh and ofVboMesh being the last one an advantage due the ability to create custom Vertex Buffer.
For Light baking, it's important that the geometry have a proper UV map. When the assets to be baked have no UV coords or the the UV texture coords are set for a LUT or share texture areas, ofxGPULightmapper allows generating a set the coordinates suitable for a Light Map and handles separately the coordinates of the model's textures and the coordinates of the lightmapper.
c++ // Mesh model [VBO] ofVboMesh mesh; // Generate lightmap coords for the model lightmapper.lightmapPack(mesh);
/ baking /
// Draw geometry with texture and baked light material.begin(); material.setUniformTexture("texture", texture, 0); material.setUniformTexture("lightmap", lightmap.getTextureReference(), 1); mesh.draw(); material.end();
Triangle Packer by @andsz https://github.com/ands/trianglepacker
Custom Light direction, AO and light bounces
For custom control of light direction, utilize the functions
begin/end ShadowMap and begin/end Bake. The library will manage internally the shadow map and biased matrix.
This technique is useful for calculating ambient occlusion or performing light bounces.
c++ / AO baking */ ofLight light;// For generic AO, light comes from everywhere glm::vec3 lightDir = glm::sphericalRand(radius); light.setPosition(lightDir);
// Update ShadowMap lightmapper.beginShadowMap(light, 10, 0.01, 100); { // draw the scene renderScene(); } lightmapper.endShadowMap();
// Bake light lightmapper.beginBake(lightmap, sampleCount); { // draw geometry node.transformGL(); mesh.draw(); node.restoreTransformGL(); } lightmapper.endBake(lightmap); ``