Ben's Edits of MeshOptimizer v2.1.7

Released on 09/14/2023

Basic Usage

Use --version to print the version and your license information.

Basic usage:

> MeshOptimizer [OPTIONS] -f <path_to_input_file> -o <path_to_output_file>

Use --help to get a list of all available command line flags. Currently the --help output is as follows:

Options:
  -h,--help                   Print this help message and exit
  --config,--ini              Read an ini file
  -o,--output_file TEXT       Output filename. If it is not provided, it is auto-generated.
  --version                   Display program version information and exit
[Option Group: Required]
  Required options
  [At least 1 of the following options are required]
  Options:
    --dump_config{}             Dumps the config file set from current settings (without the input file and output file if given) and immediately exits. Config is either written to console or to file if filepath is provided. E.g. --dump_config config.TOML will write the current settings to config.TOML file.
    -f,--input_file TEXT        Filename to process.
[Option Group: optimization_level]
  Optimization Level
  [At most 1 of the following options are allowed]
  Options:
    -i,--info                   Output only the .json file with model details and quit.
    -c,--convert                -c0: Convert only (no optimization). Same as -c.
                                -c1: Convert only, one level up from '-c' (import/export to/from the internal Scene).
                                -c2: Everything except decimation.

    --tris INT:POSITIVE [50000]
                                Target triangle count, enables decimation.
[Option Group: opt_params]
  Optimization Params
  Options:
    --skip_mesh_merger          Skip mesh merging.
    --skip_decimation Needs: --tris
                                Skip geometry decimation.
    --ignore_parallel_geometry  Skip extra steps that ensure that nearby parallel layers are transformed with the same decimation operations. Appropriate for apparel and footwear CAD assets.
    --ignore_crossing_check     Skip extra steps that prevent decimation to create new intersections.
    --remove_obstructed_geometry
                                Remove geometry that is obstructed.
    --bake_small_features       Detect and bake small features into textured quads.
    --detect_instances Excludes: --freeze_transforms
                                Detect identical mesh instances.
    --freeze_transforms Excludes: --detect_instances
                                Bake node transforms into vertex attributes and set all node transforms to identity. Will clone meshes if instances exist. Implicitly turns on --reset_scaling.
    --allow_zero_accessors      Allow glTF accessors that do not reference buffer views in output.
    --force_float_vert_attribs  Forces 4 byte floating point data for all vertex attributes.
    --embedded_gltf             If the requested output is a .gltf and this flag is set, image and geometry data will be embedded in the .gltf file.
    --dont_export_tangents      Tangent vertex attribute won't be exported even if the primitive's material has a normal map. This may cause normals from textures to be oriented incorrectly.
    --preserve_empty_nodes      Don't remove leaf nodes which don't reference any scene object.
    --ignore_polygon_intersections
                                Do not split the geometry on intersections.
    --force_poly_count          Don't stop decimation until poly count is hit. This ignores shininess and doesn't bound the error norm.
    --scanned_model             Perform operations specific to scans like crease smoothing.
    --file_size_limit FLOAT:POSITIVE Excludes: --skip_tex_opt
                                Enforce output file size limit in MB.
    --force_file_size_limit Needs: --file_size_limit
                                Don't stop decreasing texture quality until the file size limit is hit. Using this option may severly degrade texture quality.
[Option Group: runtime]
  Runtime
  Options:
    -j UINT [32]                Number of threads to run. Use -j0 for the single-threaded algorithm. Allocating fewer threads than CPU cores is useful if you want to run other tasks on the machine.
    -v,--verbose                Enable verbose (debug) output.
    --skip_scene_validation     Skip scene data validation that happens after each task.
[Option Group: misc]
  Miscellanious
  Options:
    --remove_animations         Remove all animations present in the model.
    --preserve_morph_targets    Don't bake non-animated morph targets into meshes.
    --reset_center{center} :value in { none, center, bottom }
                                The center of the scene is set to the origin of the coordinate system, or the bottom of the scene aabb. Specifying 'none' is the same as not setting the flag. Can use it with -c1, -c2 or with optimization.
    --reset_scaling             Remove reflection transforms from the scene.
    --remove_cameras            Remove any existing cameras from the file.
    --remove_lights             Remove any existing lights from the file.
    --one_primitive_per_mesh    Allow a maximum of one primitive per one mesh in the glTF output.
    --scale_size FLOAT          Size in meters to which model extents will be scaled to.
    --scale_dimension ENUM:value in { x, y, z } Needs: --scale_size
                                Dimension (x, y, or z) to scale model in.
    --rotation FLOAT x 3        Rotation [yaw pitch roll] in degrees to apply to model
[Option Group: matTex]
  Texture and Material Settings
  Options:
    --convert_spec_gloss        Convert glTF's KHR_materials_pbrSpecularGlossiness to standard pbr workflow.
    --max_tex_size INT [2048]  Excludes: --skip_tex_resize
                                Maximum texture size. Textures larger than this size will be scaled down to it.
    --skip_material_visibility  Skip material visibility computation.
    --pot_textures              Force all textures to power of two dimensions.
    --square_textures Needs: --pot_textures
                                Force all textures to square dimensions.
    --skip_tex_fill             Skip unused texture area filling.
    --skip_alpha_boost          Skip alpha mask boosting designed to prevent alpha tested textures from vanishing at a distance.
    --aggressive_alpha_removal  Relaxes the conditions to remove alpha channels based on alpha value threshold and total opaque area covered by a material.
    --skip_material_data_cleanup
                                Skip duplicate, unused and redundant material data cleanup. Requires -c1 and --skip_tex_opt.
    --skip_alpha_mode_cleanup   Skip alpha mode cleanup based on uv coverage.
    --skip_normal_map_sanitization
                                Skip sanitization of normal maps. Most importantly clamping them so that they do not point away from the vertex normals.
    --skip_normal_baking Excludes: --minimize_materials --force_uv_unwrap
                                Skip normal baking.
    --max_baking_resolution INT Maximum resolution of textures to be baked.
    --atlas_padding INT:INT bounded to [0 - 10]
                                Number of pixels to be used in atlas padding.
    --skip_extra_uv_layer_removal Excludes: --force_one_uv_layer
                                Skip removal of unused and duplicate uv layers.
    --skip_stray_uv_fixing      Skip stray uv polys relocation in order to compactify uv space.
    --skip_uv_unoverlapping     Skip unoverlapping uv polys. This may result in bad texture baking results.
    --minimize_materials Excludes: --skip_normal_baking
                                Undertake processes which aim to minimize the number of materials present in the output file, potentially at the expense texture space and rendering performance.
    --atlas_single_color_tex    If set, single color textures will be atlassed if possible, instead of being replaced with a material factor.
    --force_uv_unwrap Excludes: --skip_normal_baking
                                Force unwrapping of tiled UVs
    --remove_occlusion_maps     Remove all ambient occlusion maps from all materials in the input file.
    --force_alpha_mode ENUM:value in { none, opaque, mask, blend }
                                Force all materials in the scene to the specified alpha mode. none is the default and doesn't change any alpha modes.
    --force_one_uv_layer Excludes: --skip_extra_uv_layer_removal
                                Remove occlusion maps which use UV layer > 0. Crash if there is more than one UV layer legitimately used in any material. Don't create new UV layers in AO baking. Don't remove existing unused UV0 layers.
    --skip_duplicate_material_cleanup Needs: --skip_normal_baking
                                Materials which are duplicate (identical) won't be merged into one.
[Option Group: texOpt]
  Texture Optimization
  Options:
    --skip_tex_resize Excludes: --max_tex_size
                                Skip texture resizing.
    --skip_early_tex_resize     Skip resizing textures during loading. This may improve texture quality but will drastically increase memory consumption
    --skip_tex_opt Excludes: --file_size_limit
                                Skip texture optimization.
    --skip_tex_crop             Skip texture cropping.
    --skip_texel_density        Skip texel density based texture resizing.
    --target_tex_density :POSITIVE
                                Target texel density to be used in texture optimization in pixels/maximum_scene_dimension. If undefined median is used.
    --tex_opt_compression INT:INT bounded to [0 - 100] [80]  Excludes: --lossless_tex_opt
                                Texture compression level, 100 being max quality.
    --norm_opt_compression INT:INT bounded to [0 - 100] [80]  Excludes: --lossless_norm_opt
                                Normal map compression level, 100 being max quality.
    --mr_opt_compression INT:INT bounded to [0 - 100]
                                Metallic-roughness map compression level, 100 being max quality. If not specified tex_opt_compression will be used.
    --lossless_tex_opt Excludes: --tex_opt_compression
                                Use lossless texture compression.
    --lossless_norm_opt Excludes: --norm_opt_compression
                                Use lossless texture compression for normal maps.
    --skip_atlassing            Skip arranging textures into atlases.
    --use_ktx Needs: --pot_textures
                                Use KTX2 as output texture format, instead of JPEG/PNG.
    --allow_ktx Needs: --pot_textures
                                Allow KTX2 as output texture format.
    --alpha_mask_tex_density    Enables texel density based resize for alpha mask materials.
[Option Group: ao]
  Ambient Occlusion Baking
  Options:
    --skip_ao_baking Excludes: --ao_radius --ao_max_resolution --ao_strength
                                Skip ambient occlusion baking.
    --ao_strength FLOAT:FLOAT bounded to [0.1 - 3] Excludes: --skip_ao_baking
                                Ambient occlusion strength, higher values mean darker AO.
    --ao_radius INT:INT bounded to [1 - 20] Excludes: --skip_ao_baking
                                AO baking radius as a percentage of the scene size.
    --ao_max_resolution INT:INT bounded to [512 - 2048] Excludes: --skip_ao_baking
                                Maximum AO baking resolution.
[Option Group: draco]
  Draco
  Options:
    --draco_encode              Apply draco compression to output glTF.
    --allow_draco_decode        Decode draco encoded files on input.
    --draco_method ENUM:value in { edgebreaker, sequential }
                                Draco compression method.
    --draco_speed INT:INT bounded to [1 - 10]
                                Encoding speed, lower means higher compression quality.
    --draco_pos_bits INT:INT bounded to [1 - 16]
                                Position quantization bits.
    --draco_nor_bits INT:INT bounded to [1 - 16]
                                Normal quantization bits.
    --draco_uv_bits INT:INT bounded to [1 - 16]
                                UV quantization bits.
    --draco_col_bits INT:INT bounded to [1 - 16]
                                Color quantization bits.
    --draco_gen_bits INT:INT bounded to [1 - 16]
                                Generic quantization bits.
[Option Group: fbx]
  FBX
  Options:
    --output_fbx                Output FBX file.
    --fbx_ascii Needs: --output_fbx
                                Output ASCII Fbx.
    --roughness_as_shininess Needs: --output_fbx
                                Output roughness in shininess exponent map/factor.

Configuration Files

Instead of specifying lengthy command lines, configuration files may be used. To use a config file add a path to it via the --config flag:

> MeshOptimizer --config=<path_to_config_file> -f <path_to_input_file> -o <path_to_output_file>

To convert a command line to a config file, --dump_config option can be used:

> MeshOptimizer [OPTIONS] --dump_config=<path_to_config_file>

Below are a number of config files corresponding to pipelines on the VNTANA Platform. They all feature reasonable defaults for optimizing assets based on what their source is. Some specifics of these configurations include:

CLO - Sets a high target texel density because CLO files often feature very tiled UV spaces
BW - Converts specularGlossiness materials to metallicRoughness
3D_SCAN - passes the --scanned_asset flag to the optimizer, which tells it to perform some techniques specifically useful to 3D scans (see examples below)
STITCH_BAKING_ONLY - only bakes the small features present in the asset into textured quads (see examples below)
OTHER - use this if no other config file fits
NO_BAKING - disables texture and normal baking
KEYSHOT - suitable for Keyshot CAD assets
FORCE_BAKING - forcefully bakes textures, even if UV spaces are very tiled

Config files are easily editable in any text editor.

Examples

Obstructed Geometry Removal (`--remove_obstructed_geometry`)

Removes all polygons that are not visible from outside of the asset. E.g. for this asset:

The results with (left) and without (right) OGR are:

Small Feature Baking (`--bake_small_features`)

Bakes small features in the asset (such as stitches) into alpha masked quads.

Before:

After:

Instance Detection (`--detect_instances`)

Detects mesh copies which are then stored as a single mesh with multiple instances with different node transforms.

Before:

After:

Forcing polygon limit (`--force_poly_count`)

By default, MeshOptimizer will not honor the target polygon count (--tris) if its internal error norm becomes too large. This is done to prevent optimized assets having poor visuals or decimation errors. With the --force_poly_count flag this default behavior will be overridden and more effort will be put into achieving the desired poly limit.

Without poly limit forcing:

With:

Scanned Model Decimation (`--scanned_model`)

This flag will enable crease smoothing via edge flipping, as creases are often present on scanned models:

Ambient Occlusion Baking (`--skip_ao_baking`)

On by default, can be skipped with the --skip_ao_baking flag. Will not overwrite occlusion maps already present in the asset, unless --remove_occlusion_maps is passed as well.

Ben's Edits of MeshOptimizer v2.1.7

Released on 09/14/2023

Basic Usage

Configuration Files

Examples

Obstructed Geometry Removal (--remove_obstructed_geometry)

Small Feature Baking (--bake_small_features)

Instance Detection (--detect_instances)

Forcing polygon limit (--force_poly_count)

Scanned Model Decimation (--scanned_model)