Blender Archviz Tutorial: Multiple Importance Samples | 3D Interior Visualization Course: Part 28 |

in this video i'm gonna explain the multiple importance sample settings and how to set up the artificial light sources in the interior scenes so in blender we can have two sorts of artificial lights we can either press shift a go to the lights and add one of the lamps except of the sun which goes for the exterior so let's say the spot lamps which we already have in our scene by the way these two but we can also have mesh lights so a mesh light is actually a normal object one of those with a shader emissive shader applied to this object here you can see we have two spot lamps the is lamps which by the way can be added from the model manager under the materials you can find the is category in our store and download those setups so these are basically the mesh lights the mesh elements those circles with a special node setup applied to them but we can also use something much similar so just the emission shader if we want to have the most simple mesh light source the reason i'm explaining this is those two types of lights behave differently if we have spot lamps in our scene usually nothing changes if we add let's say an area lamp as you can see here if i scale it up let's enable the overlays so we have a better preview if i skate it up if i increase the energy of this lamp um except of having this huge radiation nothing really changes in the scene so those spot lamps work normally let's delete this area lamp but if i add a mesh plane and if i apply an emissive shader to it so i'm adding a new material and as a surface let's choose the emission you can see the spot lamps we still have in our scene are gone and why is that well first of all they are not gone they are actually rendering but if you have the clamping settings set up quite high like here they will be simply cut out of the rendering because if we disable when we disable the clamping you can see right now blender tries to somehow calculate those lamps in our rendering if we increase the number of samples this will continue the problem is those lamps are rendering as those ugly hot pixels so the clamping settings if we set them to any value they basically cut away those pixels from the final result what's also interesting if i start scanning down this plane you can see the lamps are becoming visible again so this is pretty interesting if you ask me so the reason for those artifacts are the multiple importance samples and if we go to the material settings here and we can find them under the surface the settings and surface and this is the option i'm talking about so if we enable or disable this uh for some of the light sources we are basically telling blender to focus the rendering power the computing power on those light sources in a situation where we have multiple small light sources like the ones here and here having this option enabled is a must because otherwise blender won't be able to find and render these lamps correctly so if i disable this for this one spot lamp here you can see it's basically gone and again if i uh if i remove the clamp settings this lamp is actually rendering but blender has a huge problem finding its source so that's why it's spraying all of those hot pixels so if it sounds a bit complicated well it actually is i would say a rule of thumb in setting up this kind of light sources is if we have mesh light sources for small lamps simply enable the multiple important samples and if you have a bigger mesh light sources let's say if you want to have a tv screen like this if you wanted to work together with those little light sources we had here for those bigger objects you have to disable the multiple important samples so right now blender since this is a huge light source blender has no problem in general to find it and to render it so we can tell well please omit this object in your calculations and focus only on the objects that have this option and enabled so yeah it that that's basically what's happening blender uh has no problem with finding this light source if we move it anywhere around the scene this will now work together with all of the other lamps in general uh in the previous blender versions it seemed like the lamps the normal lamps like the spot lamps here needed the same settings as the mesh the the small mesh light sources so we always had to include the multiple important samples right now from what i've tested it seems like it really doesn't matter for the spot lamps so the multiple important samples are really important for the mesh lights so objects with the emissive shaders as this one here or as these two is lamps we have so i really hope this clears up uh this topic for you again uh there aren't any fixed settings except of this rule of thumb i just gave you uh the way you should set up those multiple important samples uh strongly depends on the scene you're working on so if you have multiple is lights in your scene you might try uh just by trial and error disabling or enabling the settings for them and find the best solution but as i said it really strongly depends on the scene you're working on just keep this settings disabled for the big mesh light sources and keep it enabled for the small light sources thank you guys for watching this video is part of my interior visualization course in blender which you can watch for free on youtube all the necessary details and link to the full playlist can be found in the video description if you want to support what i do and access all of the 3d files used in this course plus blender ready interior setups and over 2000 blender exclusive 3d models just visit the choco for store and learn more about our subscription plans again thanks for watching and i see you soon

Channel: chocofur

Views: 1,428

Keywords: blender, blender 3d, blender guru, cg geek, tutorial, blender tutorial, blender interior, blender interior beginner, blender architecture, blender architecture tutorial, how to make, architecture, visualization, interior visualization, 3d interior visualization, interior visualization blender, interior visualization course, interior visualization secrets in blender, free, archviz, 3d, cgi, blender multiple importance, blender multiple importance sampling, blender lighting tutorial

Id: sAVxxuT9v_g

Length: 7min 42sec (462 seconds)

Published: Thu Dec 02 2021