Speed Concepting
Pierrick Picaut talks us through the process of how to rapidly visualise a bird character with Blender tools
Using Blender’s sculpting tools, Pierrick Picaut guides us through creating this adorable bird image
imade this project a while back after a week of tutoring with one of my students. We had a few free hours left and we started doodling some sculpts of birds. I felt pretty motivated about it and I found this amazing original concept by Svetlana Bukanova. I achieved this artwork in less than seven hours, which is pretty low for a 3D character output, thanks to Blender’s sculpting tools and hair system. Over the years Blender has become a competitive sculpting tool thanks to its dynamic topology system. It enables you to sculpt without thinking about topology, as Blender will generate geometry on the fly. Plus, Blender deals with heterogeneous mesh density, meaning that you can sculpt broad details and very thin ones on the same model without the need to average polygon density on the whole mesh. It’s like using Dynamesh in Zbrush without needing to update and remesh your model every time you get stuck with polygon density. As we’ll see in this tutorial, Blender enables vertex painting, enabling us to avoid painful retopology and UV creation, which helps to make the project more fun. We’ll also go over the hair system and how to cheat to rapidly create feathers. We will spend some time lighting and shading our scene and then get to the final post-production in Photoshop.
01 Block the Base mesh
I open the reference in the UV image editor and put it into the corner so I can always have an eye on it. In edit mode, I cut the base cube in half using Edge Loop (Ctrl+r) and remove the left half of it (X). I’ve then added a Mirror Modifier with clipping enabled and set a Subdivision Modifier with a level of 3 to get a very smooth geometry. Using simple extrusions (E) and Loop Cuts (Ctrl+r) I’ve tried to nail the base shape of the character. Using box modelling to create the base mesh, despite it not being my favourite method, is very handy to mix up large and thin parts of the body rapidly and set the basic shapes and gestures. It can be quite complicated to achieve such a result pulling clay in sculpt mode.
02 rough sculpting
Once I have a decent base mesh, I can exit edit mode, apply the Mirror Modifier and then the Subdivision Modifier. This will provide me with a raw base mesh to start sculpting on. I go into sculpting mode and enable dynamic topology using Subdivide Collapse mode and the Constant Detail option. I prefer to use Constant Detail as you don't need to be concerned about whether you’re zooming in on your model or not. Relative Detail is distance based which I feel is really unnatural. Subdivide Collapse mode will prevent you from generating too much unnecessary geometry. Using the Grab brush and the Clay Strips brush I rapidly adjust the base proportions of my character and set landmarks such as the beak and eyes sockets. I keep the detail level as low as possible in this first stage.
03 shape the head
I add a mirrored UV sphere and extrude inward some of the centre loops to create the iris and pupil landmarks. I can now sculpt around the eyes as I have a good landmark to work on, to slightly revise proportion and lay down eyebrows, eyelashes, reshape the beak and draw the edge of the mouth using the Crease and standard brush. I slightly increase the detail level in this stage. Note that the Detail Size option has changed in the latest Blender version and is now more intuitive, as higher polygon generation while it was inverted in the previous version. Whenever you're struggling to set the right detail value, just use the eye dropper and click the area you want to work on. This will give you the current detail level of the clicked area. You can then easily figure out the detail level you will use if, for example, you want polygon density to be doubled.
04 refine Proportions
Using a very large Grab brush, I refine the general proportion of the character. Using
cheat with reality When working on a stylised character, don't feel forced to respect shading rules at all cost. To make things simple, none of the metallic shaders need to have a pure white reflectivity; this is what happens in real life, but, when I do a cartoonish character, I often put a bit of colour into the glossiness shader to boost saturation and vibrance. This makes it look less realistic, but more appealing for my final model.
a Smooth Falloff, and as my mesh density is still pretty low, I can easily change the gesture of the character without creating artefacts.
05 sculpt the feet
I can now work on the feet. We often smooth our mesh while sculpting (holding Shift) and tend to get very rounded shapes. Unfortunately, this may result in fingers that look like sausages. Whenever it comes to fingers or toes, I always try to work with very exaggerated articulation and tendons landmarks. I then add flesh and smooth the entire thing. Having a strong base sculpt before sculpting keeps your fingers believable with correctly defined articulation. Even if our reference has very rounded fingers, it's good to make them with this method as it will then be easier to adjust than trying to fix appearance problems. With the Crease brush I dig some lines on the fingers and define claws. I finally rework the general proportion with the Grab brush.
06 complete sculpting
I can now increase Detail Size and sculpt details around the eyes and the mouth. I'm only concerned by the feet and face area as the rest of the body will be covered with fur and feathers, so we won't see any sculpted details here and this enables me to keep a decent polycount. Once I've finished creating these details I like to use the Pinch brush to define hard edges and refine detail features like wrinkles of the toes. I'm mixing pinching with smoothing to get nicely defined lines and a smooth surface. The Pinch brush can be very handy for correcting curvature of large areas when used with a large brush size. You can disable dynamic topology when correcting curves in order to prevent vertices from collapsing and/or generating any unnecessary geometry.
07 vertex Painting
Before I start vertex painting, I set a rapid 4 position light set-up with a key light, 2 rim light, one green and one blue as on the reference image and a fill light to avoid too-dark areas. I've then used a couple of decimate modifiers to drastically reduce my polycount without losing details. I ended up with a mesh that had a 80% lower density. This enables me to work smoothly with vertex painting and avoid artefacts. In vertex paint mode (V), I generate a first vertex colour layer using the Dirty Vertex option that will output me a black and white cavity layer. I then create a new layer and start working with the standard brush, painting my main colours. I've stored the colours I was using along the way using the painting palette available under your colour selector.
08 finish Painting
Using the Jitter and Spacing options of my brushes, I create variation in the painted colour to get a more natural result. I will also use this to get better colour transition on the feathery parts of the body and switch back to the regular and harder brush to clean the eyes, beak and brows area. 09 shade the Body I create a new material for my character and load the cavity
and vertex colour using a pair of Attribute nodes. Note that you can now load your vertex colour layer using Vertex Color nodes which make it more handy. Using a colour ramp, I can work on curvature contrast and overlay it onto my base colour using a Mix Color node. To achieve more variation in the colour I've overlayed a generated noise texture and revised my vertex colour painting, covering some of the spots generated before. I was able to control the noise influence by creating masks using a separate RGB node on my base colour coupled with a colour ramp.
10 improve Base colour
I like to add a Fresnel effect on the colour whenever I work on a cartoony character. I use the Fresnel node using the facing option and colour ramp to control it. This enables me to drive a RGB Curves node and mix it with the base colour to make outward-pointing normals and edges, to have a lighter colour and give more depth to my character even with our simple diffuse shader.
11 ADD reflectivity
I add a glossy shader and mix 2 roughness values using a Fresnel node controlled with a colour ramp. I then isolate the toes using a separate RGB node to generate a mask and set a new glossy shader using the same method as the first one to control roughness. As I can't mask the beak and claws using a generated mask, I paint a mask using a new vertex colour layer. I can now mix different glossiness values using these masks on my character to get the beak and claws more shiny than the other parts. I've then modified the Fresnel effect using the colour ramp to get a doubled line on the very edge of the character. As it drives contrast and glossiness, it will really help the character to pop out of the picture. 12 first layer of fur/feathers When I started this project I knew I would have to find a way to avoid creating and distributing real feathers on the body as this can be very complicated when you want to achieve a good result. It's very time consuming, so we will use fur instead and cheat a little later on. I first create a hair system in the Particle System tab, setting the length to 0.18 and 2,000 strands. I start isolating the fur creating a vertex group that will drive fur density. Weight assigned to the group will tell Blender where to generate strands from our first particle system. I'll first remove big chunks of vertices from the group using selection tools in edit mode. I can then work more precisely using weight painting mode.
13 comb AND shape hairs
I can now comb the hairs I've grown before. Be aware that as soon as you start combing you won't have acess to the hair system base option like length and number. You can modify it using combing tools but it's better to start with a fairly correct base hair system. I advise you to save a copy of your model before going into comb mode if you need to recover these options. I just brush the character to get a nice flow with the Deflect Emitter set to the default value.
This is a cool feature that will prevent hairs from pointing inward and creating awful artefacts. I can then generate children strands with the interpolated option to give the fur way more density. Magic happens when we play with the clumping option and testing the clump (0.75) and profile factor (-0.18) we easily achieve a nice featherlike fur system. I can now tweak my combing, smoothing everything out and adding some strands manually here and there to avoid holes.
14 shade the hairs
It’s now time to add a new material slot to our character, give it a relevant name and tell our hair system to use this material. I source the vertex colour and really increase its brightness with a curve so that the hair shaders react correctly. I’m using two Hair BSDF nodes, one for reflection and the other for transmission. I use an Add node to mix them together and use a mix shader before the Add shader to reduce the reflection influence.
I can then add these on top of a simple diffuse shader. I use the Hair Info node and connect the Intercept output to a colour ramp, enabling me to add contrast from the root to the tip of each strands by mixing it with the base colour. I then play with the Fresnel to also increase the contrast based on Fresnel effect.
15 colour the eyes
As I couldn't succeed in generating the eye texture procedurally, I've created a rapid UV of the iris by projecting it from the front view and edited it in Photoshop. I use a generated fibre texture in the miscellaneous filters and then distort it to make it stretch towards the inside of the iris. I painted the pupil with a black dot and then worked on my iris colour, masking it and playing with an orangy colour. I've also added a bit of blue tint on the middle ring of the iris to make it more interesting and resized the whole map so that it correctly fits the UVS.
16 shade the eyes
I mix a basic diffuse BSDF with a glossy shader using our stylised Fresnel effect. I've also generated a mask for the middle ring of the iris using a gradient texture to output a slightly emissive shader to make sure the eyes are bright and visible. This isn't realistic at all but I often use this trick to keep the iris colourful even when in the shadow. Again the goal here is not to be realistic but to be efficient. I then added a UV sphere around my eye mesh with a transparent shader mixed with a glossy shader to add overall reflectivity. I finally added a very light and sharp glossy shader to get crisp reflections.
17 finish the eyes
As the pupil is a bit too small, I create a shape key that will enable me to change pupil size based on the geometry in a non-destructive way (as with Blend Shapes in Maya), I can now update the right eyes using a Mirror Modifier.
18 model the feathers
As I'm lazy, I don't want to model feathers, unwrap them and paint maps. I figured that I can use a hair system on a basic shape instead. So I just extrude a simple cube and make some Loop Cuts. I create a vertex group assigning only the vertices on the centre line of the feather root. I then create a hair system and set the vertex group to drive density and length. This way, hairs are growing along the side of the feather root. You can now edit the hair strands in combing mode. Note that you can edit the hairs as a mesh instead of using the combing brush. I just enable the control point selection and size them on the Z axis to nearly zero so that they get a flat profile. I can then slightly brush
Don’t be shy You should spend some of your free time exploring websites such as Artstation, Behance and whatever art forums and galleries you can find to search for inspiration and concepts. I'm not a good concept artist, so whenever I find a cool concept I would like to make in 3D, I just send a message to the artist and ask if I can use it. Most of them will be more than happy to let you do so and know that they are inspiring at least one person. So don't be shy and ask for permission.
the top of it to get a better feather shape. I use the same shader as for the body feathers.
19 Distribute the feathers
I can now shape my feather root in edit mode and put duplicated feathers among the head, the wings and the tail. I also add a two-bone rig just to be able to rotate the head. I just parent my base mesh using automatic weight and then also parent the head feathers to the head bone. I can now slightly rotate the head towards the camera.
20 create the Branch
This a straightforward step where we just need to roughly sculpt our branch with dynamic topology. I'm using the standard, Clay Strips and Crease brush to achieve this. I also check what is viewable by the camera so that I won't have to sculpt whatever won't be seen. I then create a vertex group that will enable us to distribute small leaf particles to create the foam lichen. I download a texture from textures.com and rapidly model and project a very basic mesh to create a leaf.
21 shade the Branch
I first shade the leaf, mixing a simple diffuse with a transparent shader using texture alpha as a factor. I then directly input the texture in a Bump node as we don't need to go crazy with bump precision at this detail level. I then mix it with a glossy shader using Fresnel as usual. The little plus here is to add a translucent shader on only one of the faces of the feather using the Backfacing node. This will enable us to mimic the subsurface scattering effect we see on the back face of leaves in nature, while the side facing the sun is generally more reflective. I then distribute them using a hair system on the branch with some randomness.
Finally, I will use a tileable texture on the branch and rapidly set a basic shader. 22 render AND Postproduction I launch a test render to check how the overall image looks and fix some problems with the vertex colour under the eyes. I set the sampling level to 600, transparent background, pushed the rendering size to 200% on a base of 1,600 x 1,080. In the Render Layers tab I select a lot of render passes to be outputted (which is really not necessary, you could go with combined, AO, glossy direct and emission) and create a File Output node in the node editor to save all these passes as transparent PNGS. Hit the render button and load all the passes in Photoshop using Files>scripts and load multiple image in the same document. I then combine the pictures using AO in overlay mode to increase contrast. I then set the Glossy Direct and Transmission pass to Screen or Add and set a black mask on it. With a very light white brush I can reveal and increase a little rim lighting and reflection. I've used a jungle picture taken from the internet and blurred it a lot to create the background. I then make some colour corrections, create a vignette and duplicate the whole picture, flatten it, use the high pass on one copy and overlay it to get a crisper and sharper picture. And we're finished!.
Brush rapid selection You can access all sculpting brushes by using the number keys of your keyboard, 1,2,3… and also Shift+1, Shift+2… Just try it for a while and you'll rapidly know shortcuts for your favourite brush that will help you save time.