F3D - Fast and minimalist 3D viewer

By Kitware SAS, 2019

F3D (pronounced /fɛd/) is a VTK-based 3D viewer following the KISS principle, so it is minimalist, efficient, has no GUI, has simple interaction mechanisms and is fully controllable using arguments in the command line.

It is open-source and cross-platform (tested on Windows, Linux, and macOS).
It supports a range of file formats, rendering and texturing options.

F3D Demo
A typical render by F3D

File formats

Here is the list of supported file formats:

.vtk : the legacy VTK format
.vt[p|u|r|i|s|m] : XML based VTK formats
.ply : Polygon File format
.stl : Standard Triangle Language format
.dcm : DICOM file format
.nrrd/.nhrd : “nearly raw raster data” file format
.mhd/.mha : MetaHeader MetaIO file format
.tif/.tiff : TIFF 2D/3D file format
.ex2/.e/.exo/.g : Exodus 2 file format
.gml : CityGML file format
.pts : Point Cloud file format
.obj : Wavefront OBJ file format (full scene)
.gltf/.glb : GL Transmission Format (full scene)
.3ds : Autodesk 3DS Max file format (full scene)
.wrl : VRML file format (full scene)

Scene construction

The full scene formats (gltf/glb, 3ds, wrl, obj) contain not only geometry, but also scene information like lights, cameras, actors in the scene and textures properties.
By default, all this information will be loaded from the file and displayed.
For file formats that do not support it, a default scene will be provided.

Options

Generic Options

Options	Description
--input=<file>	The input file or files to read, can also be provided as a positional argument.
--output=<png file>	Instead of showing a render view and render into it, render directly into a png file.
--no-background	Output file is saved with a transparent background.
-h, --help	Print help.
--verbose	Enable verbose mode.
--no-render	Verbose mode without any rendering for the first provided file, to recover information about a file.
--version	Show version information.
-x, --axis	Show axes as a trihedron in the scene.
-g, --grid	Show a grid aligned with the XZ plane.
-e, --edges	Show the cell edges.
-k, --trackball	Enable trackball interaction.
--progress	Show a progress bar when loading the file.
--animation-index	Selection the animation to show. Any negative value means all animations. The default scene always has a single animation if any.
--geometry-only	For certain full scene file formats (gltf/glb and obj), reads only the geometry from the file and use default scene construction instead.
--up	Define the Up direction (default: +Y)
--dry-run	Do not read the configuration file but consider only the command line options

Material options

Options	Default	Description
-o, --point-sprites		Show sphere points sprites instead of the geometry.
--point-size	10.0	Set the size of points when showing vertices and point sprites.
--line-width	1.0	Set the width of lines when showing edges.
--color=<R,G,B>	1.0, 1.0, 1.0	Set a color on the geometry. This only makes sense when using the default scene.
--opacity=<opacity>	1.0	Set opacity on the geometry. This only makes sense when using the default scene. Usually used with Depth Peeling option.
--roughness=<roughness>	0.3	Set the roughness coefficient on the geometry (0.0-1.0). This only makes sense when using the default scene.
--metallic=<metallic>	0.0	Set the metallic coefficient on the geometry (0.0-1.0). This only makes sense when using the default scene.
--hrdi=<file path>		Set the HDRI image used to create the environment. The environment act as a light source and is reflected on the material. Valid file format are hdr, png, jpg, pnm, tiff, bmp.
--texture-base-color=<file path>		Path to a texture file that sets the color of the object.
--texture-material=<file path>		Path to a texture file that sets the Occlusion, Roughness and Metallic values of the object.
--texture-emissive=<file path>		Path to a texture file that sets the emited light of the object.
--emissive-factor=<R,G,B>	1.0, 1.0, 1.0	Emissive factor. This value is multiplied with the emissive color when an emissive texture is present.
--texture-normal=<file path>		Path to a texture file that sets the normal map of the object.
--normal-scale=<normal_scale>	1.0	Normal scale affects the strength of the normal deviation from the normal texture.

PostFX (OpenGL) options:

Options	Description
-p, --depth-peeling	Enable depth peeling. This is a technique used to correctly render translucent objects.
-q, --ssao	Enable Screen-Space Ambient Occlusion. This is a technique used to improve the depth perception of the object.
-a, --fxaa	Enable Fast Approximate Anti-Aliasing. This technique is used to reduce aliasing.
-t, --tone-mapping	Enable generic filmic Tone Mapping Pass. This technique is used to map colors properly to the monitor colors.

Camera configuration options:

Options	Description
--camera-position=<X,Y,Z>	The position of the camera. Automaticaly computed or recovered from the file if not provided.
--camera-focal-point=<X,Y,Z>	The focal point of the camera. Automaticaly computed or recovered from the file if not provided.
--camera-view-up=<X,Y,Z>	The focal point of the camera. Will be orthogonalized even when provided. Automaticaly computed or recovered from the file if not provided.
--camera-view-angle=<angle>	The view angle of the camera, non-zero value in degrees. Automaticaly computed or recovered from the file if not provided.

Raytracing options:

Options	Default	Description
-r, --raytracing		Enable OSPRay raytracing. Requires OSPRay raytracing to be enabled in the linked VTK.
--samples=<samples>	5	The number of samples per pixel. It only makes sense with raytracing enabled.
-d, --denoise		Denoise the image. It only makes sense with raytracing enabled.

Scientific visualization options:

Options	Default	Description
-s, --scalars=<array_name>		Color by a specific scalar array present in the file. If no array_name is provided, one will be picked if any are available. This only makes sense when using the default scene. Use verbose to recover the usable array names.
--comp=<comp_index>	-1	Specify the component from the scalar array to color with. Use with the scalar option. -1 means magnitude. -2 means direct values. When using direct values, components are used as L, LA, RGB, RGBA values depending on the number of components.
-c, --cells		Specify that the scalar array is to be found on the cells instead of on the points. Use with the scalar option.
--range=<min,max>		Set a custom range for the coloring by the array. Use with the scalar option.
-b, --bar		Show scalar bar of the coloring by array. Use with the scalar option.
--colormap=<color_list>		Set a custom colormap for the coloring. This is a list of colors in the format `val1,red1,green1,blue1,...,valN,redN,greenN,blueN` where all values are in the range (0,1). Use with the scalar option.
-v, --volume		Enable volume rendering. It is only available for 3D image data (vti, dcm, nrrd, mhd files) and will display nothing with other default scene formats.
-i, --inverse		Inverse the linear opacity function. Only makes sense with volume rendering.

Testing options:

Options	Description
--ref=<png file>	Reference image to compare with for testing purposes.
--ref-threshold=<threshold>	Testing threshold to trigger a test failure or success.

Window options:

Options	Default	Description
--bg-color=<R,G,B>	0.2, 0.2, 0.2	Set the window background color. Ignored if hdri is set.
--resolution=<width,height>	1000, 600	Set the window resolution.
-z, --fps		Display a frame per second counter.
-n, --filename		Display the name of the file.
-m, --metadata		Display the metadata. This only makes sense when using the default scene.
-f, --fullscreen		Display in fullscreen.
-u, --blur-background		Blur background. This only makes sense when using a HDRI.

Rendering precedence

Some rendering options are not compatible between them, here is the precedence order if several are defined:

Raytracing (-r)
Volume (-v)
Point Sprites (-o)

Interaction

Simple interaction with the displayed data is possible directly within the window. It is as follows:

Click and drag with the left mouse button to rotate around the focal point of the camera.
Hold Shift then Click and drag horizontally with the right mouse button to rotate the HDRI.
Click and drag vertically with the right mouse button to zoom in/out.
Move the mouse wheel to zoom in/out.
Click and drag with the middle mouse button to translate the camera.
Drag and Drop a file or directory into the F3D window to load it

Some options can be toggled directly using interactions:

Press S key to toggle the coloration by scalar.
Press B key to toggle the display of the scalar bar, only when coloring with scalars.
Press P key to toggle depth peeling.
Press Q key to toggle Screen-Space Ambient Occlusion.
Press A key to toggle Fast Approximate Anti-Aliasing.
Press T key to toggle tone mapping.
Press E key to toggle the display of cell edges.
Press X key to toggle the trihedral axes display.
Press G key to toggle the XZ grid display.
Press N key to toggle the display of the file name.
Press M key to toggle the display of the metadata if exists.
Press Z key to toggle the display of the FPS counter.
Press R key to toggle raytracing.
Press D key to toggle the denoiser when raytracing.
Press V key to toggle volume rendering.
Press I key to toggle opacity function inversion during volume rendering.
Press O key to toggle point sprites rendering.
Press F key to toggle full screen.
Press U key to toggle background blur.
Press K key to toggle trackball interaction mode.

Other interactions are available:

Press H key to toggle the display of a cheat sheet showing all these hotkeys and their statuses.
Press ? key to dump camera state to the terminal.
Press ESC key to close the window and quit F3D.
Press ENTER key to reset the camera to its inital parameters.
Press SPACE to play the animation if any.
Press LEFT to load the previous file if any.
Press RIGHT to load the next file if any.
Press UP to reload the current file.