3D World


Blender Stu­dio art di­rec­tor Andy Go­ral­czyk ex­plains the light­ing and ren­der­ing process for this is­sue’s cover art­work

- Andy Go­ral­czyk Andy is art di­rec­tor at Blender An­i­ma­tion Stu­dio. His work in light­ing and ef­fects con­trib­uted greatly to the look and feel of most Blender Open Movies dur­ing the past 15 years. ar­ti­fi­cial3d.art­sta­tion.com

El­lie is the main char­ac­ter from our cur­rent film pro­ject Sprite Fright. We set out to de­pict her first en­counter with a Sprite, the film’s cute for­est crea­tures. This serves two pur­poses: 1) we cre­ate a ‘per­son­al­ity pose’ to in­form the char­ac­ter de­sign and 2) we help fine-tune the fi­nal look and feel of the film.

The re­sult is a true team ef­fort among many artists at our stu­dio. The ini­tial idea came from di­rec­tor Matthew Luhn, who worked with sto­ry­board artist Dirk van Dul­men on a cou­ple of con­cepts for the over­all lay­out. Th­ese were re­fined by co-di­rec­tor Hjalti Hjal­mars­son. In the mean­time pro­duc­tion de­signer Ricky Nierva su­per­vised sculpt­ing wiz­ard Julien Kas­par to cre­ate a uni­fied look for the char­ac­ter sculpts.

Pablo Fournier, char­ac­ter an­i­ma­tor at our stu­dio, posed El­lie and the Sprite ac­cord­ing to the con­cept. Kas­par car­ried out pose re­fine­ments us­ing Blender’s sculpt­ing tools fol­low­ing paint-over sug­ges­tions from con­cept artist Vivien Lulkowski. Shad­ing artist Si­mon Thommes cre­ated some im­pres­sive pro­ce­dural ma­te­ri­als for all ob­jects, and fi­nally it was my job to give the im­age a clear and ap­peal­ing light­ing scheme.

Be­ing at the end of such a pro­duc­tion pipe­line puts a lot of re­spon­si­bil­ity in the hands of the light­ing artist. Good light­ing helps make all the pre­vi­ous steps shine while main­tain­ing clar­ity and sto­ry­telling. In this tu­to­rial we learn how to work with lights in Blender’s Cy­cles ren­der en­gine to il­lu­mi­nate a typ­i­cal char­ac­ter-cen­tric shot in one of our films.


Be­fore we start any ren­der, let’s first ad­just the Cy­cles set­tings for an op­ti­mal, rel­a­tively speedy ren­der. We don’t need a high de­gree of fi­delity in the bounce light since we’re go­ing to ‘cheat’ a lot. In the Light Paths tab un­der Max Bounces, set the to­tal to 3 and Trans­parency to 32. In the Clamp­ing sub­cat­e­gory, leave Di­rect Light at 0.00 and en­sure that In­di­rect Light is at 10.00. Dis­able Re­frac­tive and Re­flec­tive Caus­tics and set Fil­ter Glossy to 1.00.


In the Sam­pling tab, set Ren­der to 200 and cap View­port at 100. Check De­nois­ing for Ren­der and View­port and set them both to Open­im­age­de­noise. We are go­ing to take ad­van­tage of Blender’s real-time de­nois­ing ca­pa­bil­i­ties to get a clearer im­age while we’re ad­just­ing the light­ing. Set Start Sam­ple to one (this pa­ram­e­ter sets the min­i­mum sam­ples af­ter which de­nois­ing kicks in). Lastly, make sure that the Filmic View Trans­form is en­abled un­der the Colour Man­age­ment tab.


Split your main view­port ver­ti­cally and turn the lower half into a Shader Ed­i­tor.

Then, split the top half in two again. Keep one side as Cam­era View and switch Over­lays off. This way we can iso­late parts of our im­age us­ing Bor­der Ren­der­ing with­out hav­ing to pre­view the en­tire im­age at once all the time. Re­mov­ing Over­lays helps clean up the clut­ter of non-ren­der­able

helper ob­jects like Ar­ma­tures and Emp­ties. We want to be able to read the com­po­si­tion un­ob­scured. Set the shad­ing method of this view­port to Ren­dered.


It is very hard to start light­ing from a blank slate in com­plete dark­ness. As the en­vi­ron­ment we are depict­ing is out­doors, we need a ba­sic fill light to give us a good base. In the Shader Ed­i­tor, turn Shader Type to World. By de­fault, there should be a Back­ground node at­tached to the World Out­put with a grey colour and a Strength of 1.00. Add a new En­vi­ron­ment Tex­ture node and pick a for­est-based HDRI back­ground. This will give us very sub­tle vari­a­tion in the dif­fuse and glossy re­flec­tions of the ma­te­ri­als.


We do not want the HDRI to show up in the back­ground of our ren­der: hav­ing a pho­to­re­al­is­tic back­ground would in­ter­fere with our car­toon style. Add a Mix Shader node and an­other Back­ground node. Con­nect the ex­ist­ing Back­ground to the first in­put of the Mix Shader and the new Back­ground to the sec­ond. Add a new node of type Light Path and con­nect Is Cam­era Ray with the Fac­tor in­put of the Mix Shader. This gives us in­de­pen­dent con­trol of what the cam­era sees and what lights the scene.


Add a Color Mix node and con­nect its out­put to the sec­ond Back­ground Colour in­put. Con­nect the for­est HDRI with Color1 of the Mix node. Choose a dark blue di­rectly in the RGB se­lec­tor of Color2. By tweak­ing the Mix Fac­tor we can dial in the right mix­ture be­tween the for­est HDRI and a flat, more sim­ple-look­ing colour. Make sure your for­est HDRI does not con­tain any sharp de­tails or recog­nis­able forms like peo­ple. Hav­ing soft, sim­ple high­lights should add enough in­ter­est.


Let’s add our first light! We want to es­tab­lish a clear di­rec­tion for the

08 09 10 strong­est light source first. Add a light source of type Sun to your scene. Its po­si­tion does not mat­ter, but the ori­en­ta­tion is im­por­tant. Move it slightly above the scene so you can clearly see its ro­ta­tion. For char­ac­ter ‘beauty’ light­ing, the eas­i­est ap­proach is to light from the front of the face, but never from the cam­era’s an­gle. Ro­tate the sun so it lights the char­ac­ter’s face from an an­gle, while mak­ing sure it does not look too flat.


In its Ob­ject Data prop­er­ties, set the colour of the sun to R: 1.0, G: 0.5 and B: 0.08. This should give it a warm and sat­u­rated yel­low. Set the strength pa­ram­e­ter to a value of 20.00 and its an­gle value to eight de­grees. An­gle in­flu­ences the soft­ness of the sun’s shadow. While a value of eight de­grees is not phys­i­cally ac­cu­rate, it makes the shad­ows more pleas­ing and less sharp. Make sure Cast Shadow and Mul­ti­ple Im­por­tance are checked.


In a for­est, sun­light is never com­pletely uni­form. With all those mil­lions of leaves and tree branches, there’s a lot of in­ter­play be­tween light and shad­ows. For the pur­pose of hav­ing El­lie pop from the back­ground, we place her in a brighter spot of for­est. By us­ing blocker ob­jects we can pur­pose­fully craft darker and brighter ar­eas and help em­pha­sise the light on her.

Our first blocker will cast shad­ows on the ground and mimic the sun­light com­ing through leaves. Add a Mesh Plane above our scene and scale it to cover the en­tire area.


With the main blocker selected, en­ter Edit Mode and make sure its main face is selected. Sub­di­vide it five times, then turn on Face Se­lec­tion and hit Alt+a to de­s­e­lect all. Go to the Se­lect menu in the view­port header and choose Se­lect Ran­dom. In the Tool Set­tings, ad­just the per­cent­age to 30%. Now delete the ran­domly selected faces by press­ing X, and choose ‘faces’ from the menu. Tweak the amount of faces

to your lik­ing to con­trol the sun­light’s shad­ows. In the Mod­i­fier prop­er­ties, add a Sub­surf Mod­i­fier with a ren­der level of 2.


Right now the blocker would show up in the ren­der. Ad­di­tion­ally, we have to make its ma­te­rial com­pletely black to avoid bounc­ing light into our scene. In the Shader Ed­i­tor, add a new ma­te­rial to the blocker ob­ject. Delete the Prin­ci­pled BSDF. Add a Dif­fuse BSDF and a Trans­par­ent BSDF, merge the two with a Mix Shader node into the Ma­te­rial Out­put. Make the colour of the Dif­fuse BSDF black. Next, add a Light Path node and con­nect its Cam­era out­put to the Fac­tor in­put of the Mix Shader.


It’s a good idea to sep­a­rate char­ac­ter light­ing from en­vi­ron­ment light­ing. This gives us more free­dom to ad­just light­ing an­gles in­de­pen­dently. While do­ing that, it’s im­por­tant to keep the colours of both more or less synced. Add a new light of type Area. In the Ob­ject Data prop­er­ties, set its Shape to Disk and size to 0.7 me­tres. Set its Power to 55 watts and colour sim­i­lar to the sun­light, al­beit a tad more sat­u­rated. Disk Ar­eas will be our main light type, as they yield very pleas­ant, soft shad­ows.


We place the Area light a bit fur­ther away from our char­ac­ters, fac­ing El­lie head on. Cur­rently, the main sun­light is shin­ing more from the back. With this light we will slightly favour the cam­era-fac­ing side of the char­ac­ters, light­ing El­lie’s face rel­a­tively flatly while still fol­low­ing the gen­eral di­rec­tion of sun­light. A de­vi­a­tion of around 30-40 de­grees around the Z axis is fine.


The char­ac­ters need a colder fill light to bal­ance their skin tones. This will also add some sub­tle colour shift­ing in the core shad­ows (which makes the light­ing less rigid). Add an­other Disk Area light, this time with a colour of R: 0.10, G: 0.35 and B: 1.00. It’s a slightly pur­ple blue, which fits bet­ter into an even­ing/afternoon colour scheme. Make its Power 45 watts and give it a gen­er­ous size of 1.4 me­tres (around the full head-to-toe length of the char­ac­ter). Aim it at El­lie in be­tween the sun and key Area an­gle.


Now we need to en­sure that El­lie and the Sprite are sep­a­rated enough from the back­ground so

that their sil­hou­ettes read clearly. Char­ac­ter sep­a­ra­tion is usu­ally achieved with rim light­ing. You can place Rim lights ei­ther favour­ing the Key di­rec­tion or from the op­po­site an­gle. With our first Rim, we will favour the sun­light. Du­pli­cate the Key light and ro­tate it, so it shines at our char­ac­ters from be­hind. Leave its size at 0.7 me­tres, but change Power to 43 watts.


We need to make sure that the sec­ond Rim light is still mo­ti­vated by the sun­light, so we’ll treat it as a bounce that hap­pens when the sun hits the ground un­der­neath El­lie. Place a Disk Area with a size of 0.7 me­tres and power of 10W be­hind the char­ac­ter’s head, slightly favour­ing an up­wards an­gle. Choose a colour of around R: 1.000, G: 0.40, and B: 0.03 which will now re­sult in a slightly more yel­lowor­ange tone.


For achiev­ing max­i­mum ap­peal, avoid sharp shad­ows and ex­tremely dark parts in the mid­dle of the face. Add an­other Disk Area with a size of 0.1 me­tres and a power of 100 mw. This is ex­tremely sub­tle, but it will help us soften the ter­mi­na­tor around the cheek­bones. Po­si­tion it close to your char­ac­ter’s jaw­line. By slowly dialling in the in­ten­sity we make sure that it looks de­lib­er­ate. It should very sub­tly soften the face with­out bright­en­ing it too much from below.


The Sprite’s face is cur­rently lost in shadow. Add an­other Disk Area light and po­si­tion it close to the Sprite’s face. Make it very small, around 0.05 me­tres. Set its colour close to your char­ac­ter’s skin tone, in this case R: 0.47, G: 0.30 and B: 0.15. Set its power to 180 mw. We are try­ing to cre­ate the il­lu­sion of light bounc­ing from El­lie’s face and bright­en­ing up the Sprite. Be care­ful to not make it too strong though; it should still feel like it’s mo­ti­vated by the scene.


Du­pli­cate the Sprite’s key and ro­tate it around their face on the Z axis. We want to aim it more from the cam­era’s di­rec­tion. Colour it in the same tone as El­lie’s fill, a pur­ple blue. Set its power to 40 mw. This will even out the warm key and bal­ance the green­ish skin tone of the Sprite, soft­en­ing up the fa­cial fea­tures and adding a bit more em­pha­sis on the face in gen­eral. Tweak the ra­tio be­tween key and fill so it looks nat­u­ral.


We are go­ing to use some block­ers to darken the cor­ners of our im­age. This could be done as a post-pro­cess­ing vi­gnette. How­ever, de­pend­ing on the sit­u­a­tion a post ef­fect can of­ten look fake in the high­lights. Add two Mesh Planes be­tween the char­ac­ter’s feet and the cam­era (as shown in the screen­shot). As­sign the Blocker ma­te­rial we cre­ated in step 11 to them. En­sure that they are not too close to the ground, as their shad­ows will be too sharp. A dis­tance of 0.2 me­tres above the ground mesh should be good.


To cre­ate the il­lu­sion of light shafts, we won’t re­sort to phys­i­cally

ac­cu­rate vol­ume ren­der­ing. For a movie this is too time-con­sum­ing to ren­der. Add a Mesh Cube in the cen­tre of your scene and ro­tate it so that its lo­cal Z axis is aligned with the sun’s ro­ta­tion.

Add a new ma­te­rial to the cube in the Shader Ed­i­tor, re­move the Prin­ci­pled BSDF and add an Emis­sion shader node. Con­nect its out­put di­rectly to the Ma­te­rial Out­put’s Vol­ume socket.


Set the Emis­sion Colour to a light blue, shad­ing the vol­ume in a tone com­ple­men­tary to El­lie’s skin. This will help lift her from the back­ground. Add a Tex­ture Co­or­di­nate node, a Noise Tex­ture, a Colour­ramp and a Math node set to Mul­ti­ply. Con­nect their sock­ets with the Emis­sion node as shown in the screen­shot and then en­ter the val­ues shown.

Set the Noise to 2D: this will pro­ject it along the cube’s lo­cal Z axis re­sult­ing in streaks that re­sem­ble light shafts. Move the black han­dle of the Colour­ramp closer to­ward the white one and set the Mul­ti­ply node to 0.070.


As El­lie’s hair is quite dark, we need to cre­ate a lit­tle more in­ter­est in it. Add an­other round Area light with a size of 0.8 me­tres. Set its colour to a light blue and its power to 45 watts. Po­si­tion it above and slightly be­hind the char­ac­ter’s head, shin­ing slightly into the di­rec­tion of the cam­era. This should give us some sub­tle blue re­flec­tions in the hair.

In the Ob­ject Prop­erty’s Vis­i­bil­ity tab, uncheck the Dif­fuse op­tion to ex­clude the light from that par­tic­u­lar shad­ing pass.


Be­fore we start the fi­nal ren­der, we should tidy up the scene a bit. Se­lect all your lights and hit M in the view­port. Click Cre­ate New and name the new col­lec­tion ‘Lights.’ Re­peat the same for all the blocker ob­jects by mov­ing them to a new col­lec­tion called ‘Block­ers.’ Hav­ing a good and con­sis­tent nam­ing scheme pays off when work­ing with a big­ger team and you will be able to make sense of your old files more eas­ily. Once you are happy with your light­ing setup, press F12 to ren­der. •

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DOWN­LOAD YOUR RE­SOURCES For all the as­sets you need go to http://bit.ly/3dworld-blender
03 DOWN­LOAD YOUR RE­SOURCES For all the as­sets you need go to http://bit.ly/3dworld-blender
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 ??  ?? Film light­ing is cre­ative cheat­ing
Even in prac­ti­cal film­ing the best light­ing re­quires a great amount of cheat­ing and does not al­ways have to be rooted in re­al­ity. The light­ing should feel mo­ti­vated by the scenery, but above all it’s the emo­tion that counts. 04
Film light­ing is cre­ative cheat­ing Even in prac­ti­cal film­ing the best light­ing re­quires a great amount of cheat­ing and does not al­ways have to be rooted in re­al­ity. The light­ing should feel mo­ti­vated by the scenery, but above all it’s the emo­tion that counts. 04
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