reel

Quick renders by Xuan Prada

Quick and dirty exercises that I do when I have nothing else to do.

Cat's food - quick breakdown by Xuan Prada

The other I published a very simple image that I did just to test a few things. A couple of photographic techniques, my new Promote Control, procedural masks done in Substance Designer and other grading related stuff in Nuke. Just a few things that I wanted to try for a while.

This is a quick breakdown, as simple as the image itself.

  • The very first thing that I did was taking a few stills of the plate that I wanted to use as background to place my CG elements. From the very beginning I wanted to create an extremely simple image, something that I could finish in a few hours. With that in mind I wanted to create a very realistic image, and I'm not talking about lighting or rendering, I'm talking about the general feeling of being realistic. With bad framing, bad compositing, with total lack of lighting intention, with no cinematic components at all. The usual bad picture that everyone posts in social networks once in a while, without any narrative or visual value.
  • In order to create good and realistic CG compositions we need to gather a lot of information on-set. In this case everything is very simple. When you take pictures you can read the meta-data later in the computer. This will help to see the size of the sensor of your digital camera and the focal used to take the pictures. With this data we can replicate the 3D camera in Maya or any other 3D package.
  • It is also very important to get good color references. Just using a Macbeth Chart we can neutral grade the plate and everythign we want to re-create from scratch in CG.
  • The next step is to gather lighting information on-set. As you can imagine everything is so simple because this is a very tiny and simple image. There are not practical lights on-set just a couple of tiny bulbs on the ceiling. But they don't affect the subject so don't worry much about them. The main lighting source is the sun (although it was pretty much cloudy) coming through the big glass door on the right side of the image, out of camera. So we could say the lighting here is pretty much ambient light.
  • With only an equirectangular HDRI we can easily reproduce the lighting conditions on set. We won't need CG lights or anything like that.
  • This is possible because I'm using a very nice HDRI with a huge range. Linear ranges go up to 252.00000
  • I didn't eve care about cleaning up the HDRI map. I left the tripod back there and didin't fix some ghosting issues. These little issued didn't affect at all my CG elements.
  • It is very important to have lighting and color references inside the HDRI. If you pay attention you will see a Macbeth Chart and my akromatic lighting checkers placed in the same spot where the CG elements will be placed later.
  • Once the HDRI is finished, it is very importante to have color and lighting references in the shot context. I took some pictures with the macbeth chart and the akromatic lighting checkers framed in the shot.
  • Actually it is not exactly the same framing than the actual shot, but the placement of the checkers, the lighting source and the middle exposure remains the same.
  • For this simple image we don't need to make any tracking or rotospocing work. This is a single frame work and we have a 90 degree angle between the floor and the shelf. With that in mind plus the meta-data from the camera reproducing the 3D camera is extremely simple.
  • As you probably expected, modellin was very simple and basic.
  • With this basic models I also tried to keep texturing very simple. Just found a few references on internet nad tried to match them as close as I could. Only needed 3 texture channels (diffuse, specular and bump). Every single object has a 4k texture map with only 1 UDIM. Didn't need more than that.
  • As I said before, lighting wise I only needed an IBL setup, so simple and neat. Just an environment light with my HDRI  connected to it.
  • it is very important that your HDRI map and your plate share similar exposure so you can neutral grade them. Having same or similar exposure and Macbeth Charts in all your sequences is so simple to copy/paste gradings.
  • Akromatic lighting checkers would help a lot to place correctly all the reflections and regulate lighting intensity. They would help also to establish the penumbra area and the behaviour of the lighting decay.
  • Once the placement, intensity and grading ob the IBL are working fine, it is a good idea to render a "clay" version of the scene. This is a very smart way to check the behaviour of the shadows.
  • In this particular example they work very well. This is because of the huge range that I have in my HDRI. With clampled HDRI this wouldn't be working that good and you would probably have to recreate the shadows using CG lights.
  • The render was so quick. I don't know exactly but something around 4 or 5 minutes. Resolution 4000x3000
  • Tried to keep 3D compositing simple. Just one render pass with a few AOV's. Direct diffuse, indirect diffuse, direct specular, indirect specular, refraction and 3 IDs to individually play with some objects.
  • An this is it :)

Cat's food by Xuan Prada

Quick and dirty render that I did the other day.
Just testing my Promote Control for bracketing the exposures for the HDRI that I created for this image. Tried to do something very simple, to be achieved in just a few hours. Trying to keep realism, tiny details, bad framing and total lack of lighting intention.

Just wanted to create a very simple and realistic image, without any cinematic components. At the end, that's reality, isn't it?

Iron Man Mark 7 by Xuan Prada

Speed texturing & look-deving session for this fella.
It will be used for testing my IBLs and light-rigs.
Renders with different lighting conditions and backplates on their way.

These are the texture channels that I painted for this suit. Tried to keep everything simple. Only 6 texture channels, 3 shaders and 10 UDIMs.

 Color

Color

 Specular

Specular

 Mask 1

Mask 1

 Color 2

Color 2

 Roughness

Roughness

 Fine displacement

Fine displacement

Cubes tutorial by Xuan Prada

A few months ago, when my workmates from Double Negative were working on Transcendence, I saw them using Houdini to create such a beautiful animations using tiny geometries. They were like millions of small cubes building shapes and forms.
Some time later other people started doing similar stuff with Maya's XGen and other tools. I tried it and it works like a charm.

 Frame from Transcendence.

Frame from Transcendence.

  Frame from Transcendence.

Frame from Transcendence.

I was curious about these images and then decided to recreate something similar, but I wanted to do it in a simpler and quicker way. I found out that combining Cinema 4D and Maya is probably the easiest way to create this effect.

If you have any clue to do the same in Modo or Softimage, please let me know, I'm really curious.
This is my current approach.

  • In Cinema 4D create a plane with a lot of subdivisions. Each one of those subdivisions will generate a cube. In this case I’m using a 1000cm x 1000cm plane with 500 subdivisions.

  • Create a new material and assign it to the plane.

  • Select the plane and go to the menu Simulate -> Hair objects -> Add hair.

  • If you zoom in you will see that one hair guide is generated by each vertex of the plane.

  • In the hair options reduce the segments guides to 1 because we just need straight guides we don’t care about hair resolution.

  • Also change the root to polygon center. Now the guides growth from each polygon center instead of each vertex of the plane.

  • Remove the option render hair (we are not going to be rendering hairs) from the generate tab. Also switch the type to square.

  • Right now we can see cubes instead of hair guides, but they are so thin.

  • We can control the thickness using the hair material. In this case I’m using 1.9 cm

  • Next thing would be randomising the height. Using a procedural noise would be enough to get nice results. We can also create animations very quickly, just play with the noise values.

  • Remove the noise for now. We want to control the length using a bitmap.

  • Also hide the hair, it’s quicker to setup if we don’t see the hair in viewport.

  • In the Plane material, go to luminance and select a bitmap. Adjust the UV Mapping to place the bitmap in your desired place.

  • In the hair material, use the same image for the length parameter.

  • Copy the same uv coordinates from the plane material.

  • Add a pixel effect to the texture and type the number of pixels based on the resolution of the plane. In this case 500

  • Do this in both materials, the plane and the hair. Now each cube will be mapped with a small portion of the bitmap.

  • Display the hair system and voila, that’s it.

  • Obviously the greater contrast in your image the better. I strongly recommend you to use high dynamic range images, as you know the contrast ratio is huge compared with low dynamic images.

  • At this point you can render it here in C4D or just export the geometry to another 3D software and render engine.

  • Select the hair system and make it editable. Now you are ready to export it as .obj

  • Import the .obj in your favourite 3D software. Then apply your lighting and shaders, and connect the image that you used before to generate the hair system. Of course, you can control the color of the hair system using any other bitmap or procedurals.

  • In order to keep this work very simple, I’m just rendering a beauty pass and an ambient occlusion pass, but of course you can render as many aov’s as you need.

  • I also animate very quickly the translation of the hair system and added motion blur and depth of field to the camera to get a more dynamic image, but this is really up to you.

  • This is just the tip of the iceberg, with this quick and easy technique you can create beautiful images combining it with your expertise.