In order to render a Cinema 4D scene using a Thea engine, the Cinema 4D objects have to be converted into Thea objects.
All of Cinema 4D’s geometries should be converted out of the box. Polygon objects, primitives, generators, instances and render instances are translated into Thea objects (models and proxies). There are some objects though such as hair that their generated geometry is depending on the current frame. In this case, please enable the "Execute Preceded Passes" in Thea's Render Settings.
A Cinema 4D camera object is converted into Thea Camera. The parameters that are currently supported are projection, focal length, film offset, focus distance, near/far clipping, sensor size and zoom (in case of parallel projection). Regarding the projections, only Perspective and Parallel are available from Cinema4D to Thea. To extend Cinema 4D camera with Thea features (such as extra projection options), one has to apply a Thea Camera tag to it.
Cinema4D materials are converted automatically into Thea materials before transferred to Thea's rendering engine. Due to differences in the material system, the conversion is taking place using heuristic rules. That means there are some features/parameters in C4D materials that are not supported in Thea ones and vice versa.
The following channels are supported: Color, Diffusion, Specular, Reflection, Transparency, Bump, Alpha, Luminance, Fog and Displacement.
In any case, the color and the texture parameters are preserved unmodified (only for the channels described above). Brightness range value is [0,100], since it is multiplied with the color.
The shaders that are supported in Thea materials are Color, Bitmap, Color Mograph and any procedural that operates in UV coordinates. To handle the procedurals, a Thea material applies Texture Baking on them. This procedure generates a bitmap based on the shader, which can be used later in Thea's render engine as bitmap texture. Texture Baking can be parameterized either from the "Bake" tab in Render Settings or via a Thea Bake Tag.
Cinema 4D light objects are converted into Thea light objects. The supported parameters are color, brightness, light type, shadow type, falloff, photometric units, photometric intensity and photometric data (IES). To convert a light into sun without using a Thea Sun Tag, select an infinite, distant, parallel or square parallel light type. In order to make the sun visible, select “Shadow Maps (Soft) as shadow type.
Cinema 4D’s own interactive render region is supported. Nevertheless, it invokes production rendering from Thea Render's side. To employ Interactive Rendering (IR) in Thea Render, you have to use the Darkroom. While IR runs, any object change is converted solely and transferred anew into the engine.
While this works for most of tweaks (Materials, Render Settings, Display Settings, etc.), hierarchy changes cause full retransfer of the scene.
Team Render is supported by the integrated plugin but only for animations where each client processed a full frame. Co-operative rendering on the same frame using Team Render is not supported; currently, you can only use Thea Render’s network rendering for co-operative rendering on still images. If you are about to render via Team Render, use relative paths in resources (textures, hdr), otherwise if the absolute path is not valid in the client, the resources won't be found.