Multi-View Render

Suppose that you desire to render two scenes into a single image (render).  This normally can be done in photoshop, or if it's a video, a video compositor.  However, if for some reason you want to do it all in Blender, it can be done.

For this entry we'll explore how to take the two following scenes:

...and render them into a single image side by side.  This approach can be used for stereoscopic rendering, or to do a dual view render, or just to combine two different scenes in a juxtaposed fashion.

Render Layers

This entry covers the use of Render Layers.  Although there are probably many uses for Render Layers, the main focus I'll cover is using them to isolate post processing control to individual objects of the scene using the compositor.

So in my initial scene, I have Suzanne and a light blue backdrop.  In an effort to use Render Layers, I have Suzanne on layer 1, the backdrop on layer 2 and the light on layer 3.

Export Transparent PNG

This is a quick tutorial on how to render an image with a transparent background.  The idea behind it is that anything that isn't modeled, essentially all parts of the "sky" that are rendered will be rendered as transparency in the PNG.  I'll go over both methods for Cycles and Blender Internal.

For Cycles, set the PNG format to RGBA, and way down in the Film panel enable Transparent.  

For Blender Internal, again set the PNG format to RGBA, but this time set the alpha in the Shading panel to Premultiplied.

When you render, the sky should be black, and when you save the image it will be transparent, as shown with the basic cube setup.

Border Render

This entry covers the ability to render only part of the scene.  In the render tab, by checking the box labeled Border, this enables the ability to designate a rectangle within the camera view to restrict the rendered area (speeding up render times) if you are only working on a small part.

Once the box is checked, pressing [SHIFT+B] will enable a box select that will work in the camera view [NUM 0].

At this point, rendering [F12] will only render the area drawn in the red dotted box.  If you check the Crop box, the black border representing the rest of the image won't be drawn.

OpenGL Render

This entry covers a quick tip on faster rendering, specifically as it pertains to faster (draft) rendering.  By using OpenGL Rendering, Blender uses the view that you see in the viewport, but with your camera to render a light weight version of your scene.  

In most cases this is most applicable to animation.  If your scene takes forever to render, or if your animation plays slowly in the viewport, you can do a fast render without changing any render or object settings.  

First we'll start with a reasonably detailed scene, with some smoothed monkeys and a textured floor.  

If we perform an OpenGL render of the scene, notice the camera view is the same, but the lighting and the textures are missing (as seen in the viewport).

This type of render can be found at the top left near the top level menu under the Render menu.  Use the OpenGL Render Image to render the current frame, and OpenGL Render Animation to render your entire animation.

Below is the short clip of an animation generated from the OpenGL render.

Render Video

This entry takes from Blender Guru's quick tip on rendering videos.  For the full video click here:

Rendering Animations the Correct Way

This entry focuses just on compositing the rendered images into a quicktime video using the Video Sequencer in Blender.  So the first step assumes that the images have already been captured (doesn't have to be Blender images, can be any jpgs or pngs).

The first step is to switch to the Video Editor view [Ctrl + LEFT].

In this view, select Add then Image.

In the dialog box select all the images related to the video sequence [A] then select Add Image Strip.

At this point the image strip should be available in the timeline.  You may have to move the image sequence so that it starts at frame 1 or 0. Set the ending time of the animation to be the same as the last frame in the image sequence.

Now back in the standard view, you can adjust the animation render properties (as below) and render a new animation.  These settings will publish a quicktime .MOV.

Quick Preview Render

When working in Render view in Cycles, sometimes the render takes too long and it's difficult to see how your changes are being effected.  Switching the Integrator to these settings will give a lower fidelity image, but a much faster render as you manipulate the scene.

Cylinder Lighting

This is a nifty approach to creating simple environmental lighting using a cylinder and the Cycles render engine.  

First we start off with our HDR or sky image.  These can be downloaded from many sites online.  See the one of the Links entries for more information.

First create a cylinder (without ends capped) and wrap your scene with it.

Next, take a side view [NUM 1 or NUM 3] and, in edit mode [TAB], hit [u] for the UV menu and select Cylinder Projection.

Next, switch over to the UV Edit view [Ctrl + LEFT].

Select Clip to Bounds to automatically have the mesh fit the image box.

Because Cycles renderer does not support image assignment to UVs yet, switch to the Blender Renderer.

Now select the image from the beginning and load it into the UV map.

Adjust the mesh so that it fits the image.

Now the cylinder can use an emmissive image texture to create light for the scene.  You can follow this entry for that: Emmissive Image

Infinite Rendering

When previewing your mesh in the viewport for the Cycles renderer, set the Preview value to zero in the Integrator section of the Scene tab.

WireFrame Render

Modifier

With the newer versions of Blender (2.70 and up), the wireframe can be applied via a modifier.  Since it's a modifier, it applies for both renderers.

In the modifier menu, it is under the Generate column.

This produces a wireframe of the mesh you have selected.

The attributes of the wireframe can be modified in the modifier panel.  The most common would be also turning on the original mesh, which can be done by unchecking the Replace Original field.

An example final render of the wireframe (material offset 1) and the original mesh.

Cycles Renderer

This entry will detail the steps to render a clay and/or wire render of your mesh.  The first is the Cycles approach which makes use of an add-on which can be found here: Blender Artist Forum

For this example, we'll use suzanne as our complex mesh.

After adding the add-on, when you select a mesh, you'll notice in the left-pane toolbar that these options are available.  Selected Meshes will apply the clay material to selected mesh, and Create Wire Object will create a separate object that is the wire frame of the mesh.  Click Apply Materials for this to take effect.

Note once again, a new clay material is added to the Monkey, and a new wire_object is created as a separate curve.

Render of wire curve and clay material.

Render of only wire curve, but with an emissive material.

Blender Internal

Same concept but for the Blender internal renderer.

To render the mesh wireframe, simply create a new Material and press the Wire button shown below.  To get even fancier, you can create two materials, and assign both to the entire mesh to create a solid with a wireframe (last image).

Solid with wireframe render.

Clay Rendering

At times it will necessary (or just cool) to see the scene rendered without textures or materials.  If you are really good at faking reality, some will ask for a "clay render" to verify that your image isn't a photograph -- that's when you know you are good.

So instead of having to create a new blank material and manually apply it to every object in your scene, there is an AddOn which will do it for you.

This AddOn can be found here: ClayRender.py

To demonstrate how simple and effective it is, I'll start with a city scene that is already textured (generated by Suicidator City Generator).

After the AddOn is installed and enabled through the User Preferences menu, on the Camera tab there is now a new section under Render where you can enable Clay Render.

Enabling Clay Render and re-rendering will give the following perfectly non-textured image.

Mist

The Mist attribute within the World settings allows you to add a gradient mist or fog to your scene based on where your camera is facing.  In showing how this works, I'll use a scene generated with the Suicidator City Generator.

At first render without the Mist, I've applied environmental lighting and a very light gray sky color, commensurate with a very over-cast (seemingly) foggy day.  The fog will be added by the mist.

Now enable Mist within the World properties panel. See the image below for a visual explanation of how the mist works.  I typically start with a very low Start value and a very low Depth value, and adjust as necessary till the scene looks correct.

From the diagram below, you can see that the Start is the point from the camera which the mist begins, and the depth is the z-distance in which the fog becomes thicker with respect to the Falloff relationship specified.

The final render with the Mist enabled gives a very nice foggy feeling, almost San Francisco style. There isn't even a need to try to put anything else in the background as the fog seems to absorb it all.