# Mapping image settings
Simplygon can generate one or more mapping images, which can be used to cast material data from the original geometry onto the reduced geometry after the processing has completed.
A Mapping image is basically a texture on the reduced geometry where each pixel contains information of which triangle and barycentric coordinate on the original geometry that the pixel corresponds to.
The settings contains basic things like the desired texture dimensions of the mapping image to create, and there is also a setting for whether new texcoords shall be generated and how these texcoords shall be generated on the processed mesh. Texcoords can either be created from scratch when using the Parameterizer, purely based on LOD geometry, or be created from the original texcoords when using the ChartAggregator.
Some settings has a prefix which means they are only relevant when the corresponding GeneratorType is used. Multiple mapping image generation currently only works with the Reduction processor.
# Supported processors
- Reduction processor
- Remeshing processor
- Impostor processor
- Aggregation processor
- Foliage processor
# Example
This example shows how to use the Reduction processor with material casting.
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
#include <string>
#include <stdlib.h>
#include <filesystem>
#include <future>
#include "SimplygonLoader.h"
Simplygon::spScene LoadScene(Simplygon::ISimplygon* sg, const char* path)
{
// Create scene importer
Simplygon::spSceneImporter sgSceneImporter = sg->CreateSceneImporter();
sgSceneImporter->SetImportFilePath(path);
// Run scene importer.
bool importResult = sgSceneImporter->RunImport();
if (!importResult)
{
throw std::exception("Failed to load scene.");
}
Simplygon::spScene sgScene = sgSceneImporter->GetScene();
return sgScene;
}
void SaveScene(Simplygon::ISimplygon* sg, Simplygon::spScene sgScene, const char* path)
{
// Create scene exporter.
Simplygon::spSceneExporter sgSceneExporter = sg->CreateSceneExporter();
sgSceneExporter->SetExportFilePath(path);
sgSceneExporter->SetScene(sgScene);
// Run scene exporter.
bool exportResult = sgSceneExporter->RunExport();
if (!exportResult)
{
throw std::exception("Failed to save scene.");
}
}
void CheckLog(Simplygon::ISimplygon* sg)
{
// Check if any errors occurred.
bool hasErrors = sg->ErrorOccurred();
if (hasErrors)
{
Simplygon::spStringArray errors = sg->CreateStringArray();
sg->GetErrorMessages(errors);
auto errorCount = errors->GetItemCount();
if (errorCount > 0)
{
printf("%s\n", "Errors:");
for (auto errorIndex = 0U; errorIndex < errorCount; ++errorIndex)
{
Simplygon::spString errorString = errors->GetItem((int)errorIndex);
printf("%s\n", errorString.c_str());
}
sg->ClearErrorMessages();
}
}
else
{
printf("%s\n", "No errors.");
}
// Check if any warnings occurred.
bool hasWarnings = sg->WarningOccurred();
if (hasWarnings)
{
Simplygon::spStringArray warnings = sg->CreateStringArray();
sg->GetWarningMessages(warnings);
auto warningCount = warnings->GetItemCount();
if (warningCount > 0)
{
printf("%s\n", "Warnings:");
for (auto warningIndex = 0U; warningIndex < warningCount; ++warningIndex)
{
Simplygon::spString warningString = warnings->GetItem((int)warningIndex);
printf("%s\n", warningString.c_str());
}
sg->ClearWarningMessages();
}
}
else
{
printf("%s\n", "No warnings.");
}
}
void RunReductionWithMaterialCasting(Simplygon::ISimplygon* sg)
{
// Load scene to process.
printf("%s\n", "Load scene to process.");
Simplygon::spScene sgScene = LoadScene(sg, "../../../Assets/SimplygonMan/SimplygonMan.obj");
// Create the reduction processor.
Simplygon::spReductionProcessor sgReductionProcessor = sg->CreateReductionProcessor();
sgReductionProcessor->SetScene( sgScene );
Simplygon::spReductionSettings sgReductionSettings = sgReductionProcessor->GetReductionSettings();
Simplygon::spMappingImageSettings sgMappingImageSettings = sgReductionProcessor->GetMappingImageSettings();
// Set reduction target to triangle ratio with a ratio of 50%.
sgReductionSettings->SetReductionTargets( Simplygon::EStopCondition::All, true, false, false, false );
sgReductionSettings->SetReductionTargetTriangleRatio( 0.5f );
// Generates a mapping image which is used after the reduction to cast new materials to the new
// reduced object.
sgMappingImageSettings->SetGenerateMappingImage( true );
sgMappingImageSettings->SetApplyNewMaterialIds( true );
sgMappingImageSettings->SetGenerateTangents( true );
sgMappingImageSettings->SetUseFullRetexturing( true );
sgMappingImageSettings->SetTexCoordGeneratorType( Simplygon::ETexcoordGeneratorType::ChartAggregator );
Simplygon::spChartAggregatorSettings sgChartAggregatorSettings = sgMappingImageSettings->GetChartAggregatorSettings();
// Enable the chart aggregator and reuse UV space.
sgChartAggregatorSettings->SetChartAggregatorMode( Simplygon::EChartAggregatorMode::SurfaceArea );
sgChartAggregatorSettings->SetSeparateOverlappingCharts( false );
Simplygon::spMappingImageOutputMaterialSettings sgOutputMaterialSettings = sgMappingImageSettings->GetOutputMaterialSettings(0);
// Setting the size of the output material for the mapping image. This will be the output size of the
// textures when we do material casting in a later stage.
sgOutputMaterialSettings->SetTextureWidth( 2048 );
sgOutputMaterialSettings->SetTextureHeight( 2048 );
// Start the reduction process.
printf("%s\n", "Start the reduction process.");
sgReductionProcessor->RunProcessing();
// Setup and run the diffuse material casting.
printf("%s\n", "Setup and run the diffuse material casting.");
Simplygon::spColorCaster sgDiffuseCaster = sg->CreateColorCaster();
sgDiffuseCaster->SetMappingImage( sgReductionProcessor->GetMappingImage() );
sgDiffuseCaster->SetSourceMaterials( sgScene->GetMaterialTable() );
sgDiffuseCaster->SetSourceTextures( sgScene->GetTextureTable() );
sgDiffuseCaster->SetOutputFilePath( "DiffuseTexture" );
Simplygon::spColorCasterSettings sgDiffuseCasterSettings = sgDiffuseCaster->GetColorCasterSettings();
sgDiffuseCasterSettings->SetMaterialChannel( "Diffuse" );
sgDiffuseCasterSettings->SetOutputImageFileFormat( Simplygon::EImageOutputFormat::PNG );
sgDiffuseCaster->RunProcessing();
std::string diffuseTextureFilePath = sgDiffuseCaster->GetOutputFilePath();
// Setup and run the normals material casting.
printf("%s\n", "Setup and run the normals material casting.");
Simplygon::spNormalCaster sgNormalsCaster = sg->CreateNormalCaster();
sgNormalsCaster->SetMappingImage( sgReductionProcessor->GetMappingImage() );
sgNormalsCaster->SetSourceMaterials( sgScene->GetMaterialTable() );
sgNormalsCaster->SetSourceTextures( sgScene->GetTextureTable() );
sgNormalsCaster->SetOutputFilePath( "NormalsTexture" );
Simplygon::spNormalCasterSettings sgNormalsCasterSettings = sgNormalsCaster->GetNormalCasterSettings();
sgNormalsCasterSettings->SetMaterialChannel( "Normals" );
sgNormalsCasterSettings->SetGenerateTangentSpaceNormals( true );
sgNormalsCasterSettings->SetOutputImageFileFormat( Simplygon::EImageOutputFormat::PNG );
sgNormalsCaster->RunProcessing();
std::string normalsTextureFilePath = sgNormalsCaster->GetOutputFilePath();
// Update scene with new casted textures.
Simplygon::spMaterialTable sgMaterialTable = sg->CreateMaterialTable();
Simplygon::spTextureTable sgTextureTable = sg->CreateTextureTable();
Simplygon::spMaterial sgMaterial = sg->CreateMaterial();
Simplygon::spTexture sgDiffuseTexture = sg->CreateTexture();
sgDiffuseTexture->SetName( "Diffuse" );
sgDiffuseTexture->SetFilePath( diffuseTextureFilePath.c_str() );
sgTextureTable->AddTexture( sgDiffuseTexture );
Simplygon::spShadingTextureNode sgDiffuseTextureShadingNode = sg->CreateShadingTextureNode();
sgDiffuseTextureShadingNode->SetTexCoordLevel( 0 );
sgDiffuseTextureShadingNode->SetTextureName( "Diffuse" );
sgMaterial->AddMaterialChannel( "Diffuse" );
sgMaterial->SetShadingNetwork( "Diffuse", sgDiffuseTextureShadingNode );
Simplygon::spTexture sgNormalsTexture = sg->CreateTexture();
sgNormalsTexture->SetName( "Normals" );
sgNormalsTexture->SetFilePath( normalsTextureFilePath.c_str() );
sgTextureTable->AddTexture( sgNormalsTexture );
Simplygon::spShadingTextureNode sgNormalsTextureShadingNode = sg->CreateShadingTextureNode();
sgNormalsTextureShadingNode->SetTexCoordLevel( 0 );
sgNormalsTextureShadingNode->SetTextureName( "Normals" );
sgMaterial->AddMaterialChannel( "Normals" );
sgMaterial->SetShadingNetwork( "Normals", sgNormalsTextureShadingNode );
sgMaterialTable->AddMaterial( sgMaterial );
sgScene->GetTextureTable()->Clear();
sgScene->GetMaterialTable()->Clear();
sgScene->GetTextureTable()->Copy(sgTextureTable);
sgScene->GetMaterialTable()->Copy(sgMaterialTable);
// Save processed scene.
printf("%s\n", "Save processed scene.");
SaveScene(sg, sgScene, "Output.fbx");
// Check log for any warnings or errors.
printf("%s\n", "Check log for any warnings or errors.");
CheckLog(sg);
}
int main()
{
Simplygon::ISimplygon* sg = NULL;
Simplygon::EErrorCodes initval = Simplygon::Initialize( &sg );
if( initval != Simplygon::EErrorCodes::NoError )
{
printf( "Failed to initialize Simplygon: ErrorCode(%d)", (int)initval );
return int(initval);
}
RunReductionWithMaterialCasting(sg);
Simplygon::Deinitialize(sg);
return 0;
}