konstantin magnus

I think @acey195 had a solution for this:

Hi Bill, you can blend colors from surrounding objects into texture maps by filtering point clouds. tex_sample_surface_colors.hipnc

A basic proof of concept for texture bombing on 3D surfaces. texture_bombing.hipnc

Hi P Sis, there is a way to apply metadata to attributes (ie. "texturecoord") with the VEX function setattribtypeinfo(). https://www.sidefx.com/docs/houdini/vex/attribtypeinfo_suite

A texture generator for image based direct lighting. This example is just using a tonemapped JPG. Though by appending ToneMap Ql the same procedure works with HDRIs, too. // INPUT vector pos_tex = set(X, Y, 0.0); vector pos_mesh = uvsample(geo_mesh, 'P', 'uv', pos_tex); vector nml_mesh = uvsample(geo_mesh, 'N', 'uv', pos_tex); float a = radians(angle); // IMAGE BASED DIRECT LIGHTING vector clr_sum = 0.0; for(int i = 0; i < samples; i++){ vector2 u = rand(pos_tex * i); vector dir = sample_direction_cone(nml_mesh, a, u); vector pos_ray = pos_mesh + nml_mesh * 1e-3; vector dir_ray = dir * range; vector pos_hit; vector uvw_hit; int prim_hit = intersect(geo_sky, pos_ray, dir_ray, pos_hit, uvw_hit); vector clr_hit = primuv(geo_sky, 'Cd', prim_hit, uvw_hit); clr_sum += clr_hit; } vector clr = clr_sum / float(samples); // OUTPUT vector color = vector(clr); assign(R, G, B, color); texture_hdri.hipnc

A minimalist generator for creating occlusion textures right in COPs. // INPUT vector pos_tex = set(X, Y, 0.0); vector pos_mesh = uvsample(geo_mesh, 'P', 'uv', pos_tex); vector nml_mesh = uvsample(geo_mesh, 'N', 'uv', pos_tex); float a = radians(angle); // OCCLUSION float occ_sum = 0.0; for(int i = 0; i < samples; i++){ vector2 u = rand(pos_tex * i); vector dir = sample_direction_cone(nml_mesh, a, u); vector pos_ray = pos_mesh + nml_mesh * 1e-3; vector dir_ray = dir * range; vector pos_hit; vector uvw_hit; int prim_hit = intersect(geo_mesh, pos_ray, dir_ray, pos_hit, uvw_hit); occ_sum += prim_hit == -1; } float occ = occ_sum / float(samples); // OUTPUT vector color = vector(occ); assign(R, G, B, color); texture_occlusion.hipnc

Currently working on a from-scratch texturing procedure that simulates water running down surfaces. Models shamelessly taken from @animatrix course files. Starting with projected points, the curves run along a volume until they drop onto the next underlying surfaces using nested while loops. The watery effect is achieved in COPs where the texture is drawn based on measuring distance from texture positions to these curves. Alright, enough art, here comes the proof of dripping :

Hey @m___clifford, it's for the attribute wrangle running over points.

Hi Max, you can measure the overall point density with pcfind() within a certain radius: int samples = chi('samples'); float radius = chf('radius'); int pts[] = pcfind(0, 'P', v@P, radius, samples); float dens = len(pts) / float(samples); f@dens = dens;

Hi Morten, here is a simplification. The ray node alone can do the shadow calculation in this case. ray_shadow.hipnc

Alternatively transform a box into camera space and boolean intersect it with your geometry. frustum_cut_boole.hipnc

Hi Kim, the volume node can create the camera's frustum, which can be transferred to point attributes for poly-cutting. frustum_cut.hipnc

I heard it was called 'falloff' before. Alternatively you could also look into a VEX function called pcfind(): https://www.sidefx.com/docs/houdini/vex/functions/pcfind.html

Great shading and lighting, Tim!

Hi MD, I have attached an example. There are also lots vellum hair tutorials on YouTube. braid.hipnc