Render that pretends to be a photo
Gleb Alexandrov here and it’s time for another Making-of. Today we’re going to talk about “The Brushes” – still life render which pretends to be a photo.
This time, the idea wasn’t preceded by a concept painting. It came purely from aesthetic experience.
There is a jar with brushes on my table. It’s so routine and usual that it’s almost invisible. But once I noticed something unusual about it. At this time of the year, about 11 o’clock in the morning sun peaks through my window. One day brushes were lit so brightly and looked so joyful that in that instant rather dirty jar became something worth rendering.
1 Blocking out the scene
In terms of modeling the scene is quite simple, nothing to brag about. I’ve started with blocking out the basic shapes – this is very important stage of the production. Better get it right now, while the scene is light and easy to manage.
Screw modifier makes wonders, really worth learning.Watch tutorial
2 Basic materials
During the the block-out phase simple materials were used. Typically, they consisted of just 1 seamless texture and were quite primitive in terms of shader complexity: just the mix between diffuse and glossy.
So, 1 mix shader and 1 texture is enough to represent the main qualities of wood (steel, glass)
3 Procedural UV coordinates
Along with uv- coordinates for texture mapping we can use Generated or Object coordinates. Thus, we can leave UV-mapping untouched and still be able to control the texture using Mapping node.
To project texture evenly and from several directions at once, use so-called Box mapping. With the help of the Blend parameter textures seams can be hidden.
4 Material layers
Go ahead and add the layers to the basic materials. To achieve the compelling look, I’d suggest to add at least 3 supplementary shaders in every material: dirt, paint, scratches.
Use black and white mask as a mix factor.
5 Painted glass material
It’s pretty complex material, so let’s decompose it.
1 Two basic materials – glass and paint
2 Both of these materials have several composite materials
3 The glass material consists of a glass and dust, dirt, fingerprints
4 The paint material consists of a translucent, diffuse, reflective, emissive shaders. Consequently, it uses diffuse, bump, translucency texture, etc.
5 Transparency texture in the paint material determines what areas are translucent (covered with a thin layer of the paint), and what areas are opaque.
6 Displacement map is also used as the normal map
Recommend trying out Cycles Dispersion Glass shader by Harri Collis.
The key light source is nothing more than a sun lamp with a soft shadows (sample size 12 cm).
To achieve a rim light effect, I created a plane and placed it at the window. Brush tops were lit separately with a spot light.
Spherical HDRi image softly illuminates the scene from all angles and creates virtually no shadows – it’s good for us in this case. What is very important about HDRi, that the reflective parts of the brushes and also the jar begin reflecting the bright areas of the HDRi. These reflections accentuate objects‘ volume and make a metal act like a “metal”, if you know what I mean.
Rotated HDRi using mapping node, searching for the most effective angle.
While Cycles is already a fantastic renderer, it still doesn’t have something similar to Directional Light yet (sun and spot lamps are similar in function but also not quite the same). So for now we had to add spot lights or invent obstacles between the object and the sun to restrict its area of influence.
7 Hair simulation
Let’s briefly explore the process of creating the hair.
7 Hair styling
Now we’re switching viewport to Particle Edit mode and trying ourselves as a stylists, cutting and combing hair.
8 Hair material
There is now a special shader for hair — in Blender 2.69. My impression is that it’s somewhat slow to render – but anyway, it looks great. Who cares.
The node called Hair Info in material editor is essential when texturing hair.
Using Intercept attribute and Color Ramp (gradient), we can control the gradient of the hair color – from the roots to the tips. Note that the gradient may haveseveral “stops”.
Combining this information with the capabilities of uv-coordinates, we can confidently dye our hair – using length (Intercept) and location relative to the particle emitter (UV).
We want photo-real render, don’t we? Leave the caustic enabled and the maximum number of bounces untouched.
When trying to render this scene out, used classical path tracing, and not the branched version, as it was more conventional for me.
Perhaps now would have done otherwise, since branched path tracing coupled with manual tweaking of the light source samples solves the problem of noise in shadows. Spot lamps and perhaps any lamps generate much noise if there is a lot of obstacles between them and the camera.
10 What could be done better?
Render was infernally slow: on my computer (i7 3690, 16gb ram, nvidia 650m) it was rendering about two days in the resolution of 1100-2200 (12,000 samples).
Though, there was a lucky coincidence — guys from Renegatt (GPUBOX software) helped me out to do a few test renders and a final render. Thanks a lot!
11 Composing and post-processing
Blender compositor is actually fine. While it has some flaws (rendering speed?), it does its job.
At the beginning of the article, we could see how the processing sequence can be done.
Last stage is cosmetic treatment. Brightness tweaks, lightening / darkening – basically, what we want here is to enhance the colors and get that extra ‘oomph’.
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