In this post, we will examine them together!<\/p>\n
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Apart from those capabilities, I have also added support for\u00a0backgroundTexture<\/strong>, where a color read from that background texture is used to color the current pixel when a ray cast from that pixel does not hit any object in the scene.<\/p>\n From now on, we have the\u00a0Textures<\/strong> tag in our input scene files. A texture has:<\/p>\n In Spheres, we calculate texture\u00a0u, v<\/strong> coordinates such that the texture could map the whole surface. In Triangles, we use barycentric coordinates to calculate u and v. Here are some outputs:<\/p>\n Please check Ken Perlin’s webpage<\/a> for detailed information on Perlin Noise.<\/em><\/p>\n This part is where I spent most of my time for this assignement. I wrote a Perlin class which initially creates the\u00a0G<\/strong> array, and a shuffled\u00a0P<\/strong> array. Then for each hit point, I floored the hitpoint coordinates, built up the 3D grid cube, assigned\u00a0e<\/strong> vectors to the vertices by selecting from G<\/strong>, using\u00a0P\u00a0<\/strong>index array to choose an index, and finally weighted those 8 corners of the cube to get a Perlin value between [0..1].<\/p>\n If the appearance is chosen as “patch”, then\u00a0(perlinValue + 1) \/ 2\u00a0<\/strong>is sent to the replace_kd operation as normalized texture color.<\/p>\n If the appearance is chosen as “vein”, then abs(perlinValue)\u00a0<\/strong>is sent to the replace_kd operation as normalized texture color.<\/p>\n Below are my outputs:<\/p>\n Bump mapping is used to give the effect of bumpings on the surfaces, without actually disturbing the geometry of the surface. It is done by changing the pointing direction of the surface normal by an amount of the difference in texture color between hitpoint u, v and neightbour u, v (as if taking the derivative) when a point on the surface is hit by a ray. The more the difference we have, the more the bump is seen. Below are my outputs of Triangle and Sphere bump mappings. Some of the outputs include the use of Perlin noise and bump mapping together, where we use the difference between the perlin values of neighbour coordinates as the bump amount, and also the color. I would like to end this post by a video of sequential renders of a slightly edited (METU logo on the wings and my name, CENK, on the tips of the wings) version of Galactica spaceship Oguz hoca<\/a>\u00a0has shared with us, together with The Imperial March!<\/p>\nTexture Mapping<\/h4>\n
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\n<\/a>![\"\"](\"http:\/\/kadircenk.com\/blog\/wp-content\/uploads\/2018\/04\/sphere_texture_blend_bilinear-1.png\")
<\/a><\/p>\nsphere_texture_blend_bilinear.xml\n(800x800)\n\/w 8 thrd, 1MSAA<\/pre>\n
<\/a><\/p>\nsphere_texture_replace_bilinear.xml\n(800x800)\n\/w 8 thrd, 1MSAA<\/pre>\n
<\/a><\/p>\nsphere_texture_replace_nearest.xml\n(800x800)\n\/w 8 thrd, 1MSAA<\/pre>\n
<\/a><\/p>\nskybox.xml\n(1600x800)\n\/w 8 thrd, 100MSAA\nGround is triangle,\nScene is inside a sphere (sky).<\/pre>\n
<\/a><\/p>\nkilleroo_diffuse_specular_texture.xml\n(800x800)\n\/w 8 thrd, 16MSAA\nWalls are grid-textured.<\/pre>\n
<\/a><\/p>\ngalactica_static.xml\n(1280x720)\n\/w 8 thrd, 36MSAA\nMETU logo on wings,\nMy name, CENK, on the tips of wings.<\/pre>\n
<\/a><\/p>\ngalactica_dynamic.xml\n(1280x720)\n\/w 8 thrd, 64MSAA, MB\nMETU logo on wings,\nMy name, CENK, on the tips of wings.\nHad some BBox vs. MB problems,\nwill solve them.<\/pre>\n
Perlin Noise Implementation<\/h4>\n
<\/a><\/p>\nellipsoids_texture.xml\n(800x800)\n\/w 8 thrd, 1MSAA\nLeft sphere is replace_all,\nRight sphere is blend_kd (reddish diffuse),\nSecond right sphere is replace_kd,\nSecond left sphere is \"patch\" perlin.<\/pre>\n
<\/a><\/p>\nperlin_types.xml (800x800)\n\/w 8 thrd, 1MSAA\nGround is blend_kd scalingFactor 0.03 \n\"patch\" perlin triangle,\nCloser left-right are scalingFactor 5\n\"patch\" and \"vein\", respectively,\nMiddle left-right are scalingFactor 1\n\"patch\" and \"vein\", respectively,\nFar left-right are scalingFactor 1\n\"patch\" and \"vein\", respectively.<\/pre>\n
Bump Mapping<\/h4>\n
\n<\/a><\/p>\nbump_mapping_basic.xml\n(800x800)\n\/w 8 thrd, 36MSAA\nGround triangle bumped by grid texture,\nSphere bumped by leather texture.<\/pre>\n
<\/a><\/p>\nbump_mapping_transformed.xml\n(800x800)\n\/w 8 thrd, 36MSAA\nGround triangle bumped by cobblestone\ntexture, Sphere bumped by leather\ntexture.<\/pre>\n
<\/a><\/p>\nsphere_bump_nobump.xml\n(800x800)\n\/w 8 thrd, 36MSAA\nLeft nobump,\nRight bump.<\/pre>\n
<\/a><\/p>\nkilleroo_bump_walls.xml\n(800x800)\n\/w 8 thrd, 16MSAA\nWalls are grid bumped,\nNo texture & bump on killeroo.<\/pre>\n
<\/a><\/p>\nspheres_perlin.xml\n(800x800)\n\/w 8 thrd, 36MSAA\nLeft \"patch\" perlin,\nRight \"vein\" perlin.<\/pre>\n
<\/a><\/p>\nperlin_types_bump.xml\n(800x800)\n\/w 8 thrd, 1MSAA\nSame setup as perlin_types.xml above,\nbut with bump mapping now.<\/pre>\n