Mesh Class

Several Morph Targets
Each surface supports multiple morph targets (also known as blend shapes), enabling vertex-level animation for expressions, shape changes, or deformations.
Quaternion-Based Tangent Basis
The tangent space (normal, tangent, bitangent) for each surface is encoded using quaternions.
8-Bit Vertex Colors
Vertex colors are stored using 8-bit precision per channel.
Dual Indexing System
Each vertex is associated with two buffers:
- Coordinate buffer: stores vertex positions
- Triangle buffer: stores unique vertex attributes
Two UV Sets per Vertex
Surfaces support two sets of texture coordinates per vertex.
Bind Pose Transformation
A bind pose matrix is stored for each mesh, even if no animations are present. This ensures compatibility with skinning systems and allows for future animation binding. See also the getBoneTransforms() function for retrieving bone matrices.

Mesh Structure#

Each Mesh instance contains:

A Bounding Box
A Bounding Sphere
One or more surfaces

Notice
				Most methods that work with surfaces use surface index 0 by default. If a method should work on all surfaces, use -1 instead. These values are usually set as default methods parameters.
			

Surfaces

A surface is a subset of the object geometry (i.e. a mesh) that does not overlap other subsets. Each surface of a mesh contains:

Name
A unique string used to identify surface within the mesh.
Bounding Box
Axis-aligned box enclosing the surface geometry.
Bounding Sphere
Spherical bound around the surface geometry.
Morph Targets (at least one)
Each surface contains at least one morph target, which stores the core vertex data: vertex coordinates (positions), normals, and tangents. Additional targets may be used for vertex animation.
Learn more in the Adding Morph Targets article.
Vertex Weights and Bones
Each vertex stores up to 4 bone indices and their corresponding weights, defining how the vertex is affected during skeletal animation.
Notice
Vertex weights are defined by:
- Four bone indices (see setWeightBones() / getWeightBones() methods);
- Four bone weights (see setWeightWeights() / getWeightWeights() methods);
- A weight count (see setWeightCount() / getWeightCount() methods).
Texture Coordinates (UV Sets)
Each vertex stores two sets of UV coordinates: the first is typically used for base textures, and the second for lightmaps or additional effects.
Vertex Colors
Each vertex can optionally store an RGBA color, typically encoded as 8-bit per channel. While the mesh itself does not render vertex colors directly, they can be accessed and utilized in materials for effects like blending, masking, or procedural shading.
See example for how to use vertex colors in a material.
Edges and spatial tree
Each surface stores edge data and a spatial tree to accelerate spatial queries such as intersection and collision detection.
Coordinate and triangle indices
Each surface includes two index buffers: coordinate indices and triangle indices. Their purpose is described in detail below.

Vertex Data and Indices#

Each mesh surface consists of triangles, with each triangle having 3 vertices. Therefore, the total number of vertices per surface is calculated as:

Total Vertices = 3 * Number of Triangles.

If a vertex is shared by multiple triangles, it would normally have to be stored multiple times, with each copy containing data such as position, normal, tangent, texture coordinates, and so on. To minimize redundancy and improve loading performance, UNIGINE uses an optimized layout that separates vertex data into two distinct buffers:

Coordinate Vertex Buffer (CVertices), which stores only vertex coordinates.
Triangle Vertex Buffer (TVertices), which stores vertex attributes such as normal, binormal, tangent, color, UV coordinates.

On the picture below, arrows are used to show normals:

Surface that contains 2 adjacent triangles. Here C0...C3 are coordinate vertices, T0...T5 are triangle vertices

The coordinate buffer is an array of unique vertex positions. In order to reduce data duplication, vertices of surface which have the same coordinates are stored only once in the buffer.

For example, the coordinate buffer for the surface presented on the picture above is the following:

Output

CVertices = [C0, C1, C2, C3]

Each triangle of the surface has 3 coordinates. We have 2 triangles, thus, we have 6 vertices, but we save in the CVertices buffer only 4, because 2 of them (C1 and C3) have the same coordinates. Each coordinate vertex contains coordinates (float[3]) of the vertex.

NoticeSince the coordinate buffer stores only non-duplicated vertex positions, the total number of vertices in the mesh and the number of entries in the CVertices buffer are the same.

The triangle buffer is an array of per-triangle vertex attribute entries. For example, the triangle buffer for the surface presented on the picture above is the following:

Output

TVertices = [T0, T1, T2, T3, T4, T5]

Each triangle vertex can store:

Normal
Binormal
Tangent
1st UV map texture coordinates
2nd UV map texture coordinates
Color

Notice

The number of vertices and triangle vertices can be different.

The number of entries in the triangle buffer (TVertices) depends on how a vertex is used across triangles:

If a vertex is shared between multiple triangles but has different attributes (e.g., different normals or tangents), multiple attribute entries will be stored - one for each variation. In the picture above, coordinate vertex C1 corresponds to two triangle vertices: T1 and T2.
If a vertex is shared and its attributes are identical across all triangles, a single attribute entry is sufficient and will be reused.

Both the coordinate and triangle vertex are indexed. There are 2 index buffers to get proper CVertex and TVertex data for each vertex of each triangle of the mesh:

Coordinate Index Buffer (CIndices) - coordinate indices, which are links to CVertices data.
Triangle Index Buffer (TIndices) - triangle indices, which are links to TVertices data.

The number of elements in these index buffers is equal to the total number of vertices of a mesh surface.

Notice

There is no actual structure called a "triangle vertex." All vertex attributes (normals, tangents, UVs, etc.) are stored separately and linked via index buffers. The term "triangle vertex" is used here only for convenience to describe how attributes are associated with vertex positions.

See the Mesh File Formats article for details on how mesh structure is organized from a file layout perspective.

Coordinate Indices#

Each vertex of a mesh surface has a coordinate index - a number of the corresponding element of the coordinate buffer, where the data is stored. For the given surface the array of the coordinate indices is as follows:

Output

CIndices = [Ci0, Ci1, Ci3, Ci1, Ci2, Ci3]

Here:

The first 3 elements are the coordinate indices of the first (bottom) triangle.
The second 3 elements are the coordinate indices of the second (top) triangle.

Triangle Indices#

Each vertex of a mesh surface also has a triangle index - a number of the corresponding element of the triangle buffer, where the data is stored. For the given surface the array of the triangle indices is as follows:

Output

TIndices = [Ti0, Ti1, Ti5, Ti2, Ti3, Ti4]

Here:

The first 3 elements are the triangle indices of the first (bottom) triangle.
The second 3 elements are the triangle indices of the second (top) triangle.

Notice

The number of the coordinate and triangle indices is the same.

Accessing a Mesh of a Mesh-Based Object#

You can access the source mesh of a mesh-based object (e.g. a static mesh, a skinned mesh and so on) via the specialized getMesh...() methods of the corresponding object class. These methods provide access to either standard or procedural meshes, with different loading strategies:

getMeshCurrentRAM() - returns the current source mesh loaded in RAM (if available).
getMeshForceRAM() - loads and returns the source mesh in RAM immediately.
getMeshAsyncRAM() - loads and returns the source mesh in RAM asynchronously.
getMeshDynamicRAM() - returns the procedural source mesh and ensures it is loaded into RAM.

For example, to access the Mesh of the ObjectMeshStatic, you can do the following:

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// a mesh-based object from which geometry will be obtained
	ObjectMeshStaticPtr box = ObjectMeshStatic::create("core/meshes/box.mesh");
	// create a mesh
	MeshPtr boxMesh = Mesh::create();
	// copy the mesh of the ObjectMeshStatic into the created mesh
	boxMesh->assignFrom(box->getMeshForceRAM());

	return 1;
}

Notice

The ObjectMeshDynamic class provides only the getMesh() method.

Copying a Mesh#

You may need to copy a Mesh in the following cases:

When you have a mesh-based object that should be copied into another mesh-based object (new or existing one).
When you have a Mesh that should be copied into another Mesh.

From One Mesh-Based Object to Another#

You can copy a mesh of a mesh-based object into another object in one of the following ways:

By passing a Mesh to a new mesh-based object:

Get a source mesh-based object.
Create a Mesh class instance as a container.
Copy the mesh of the source mesh-based object by using the getMesh() function.
Create a new mesh-based object from the Mesh instance.

For example, you can copy the Mesh of the existing ObjectMeshDynamic to the new ObjectMeshDynamic as follows:

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>
#include <UnigineWorld.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// get the existing ObjectMeshDynamic node by name
	ObjectMeshDynamicPtr source = static_ptr_cast<ObjectMeshDynamic>(World::getNodeByName("source_dynamic"));
	
	if (source != nullptr)
	{
		// create a Mesh container
		MeshPtr mesh = Mesh::create();

		// copy the mesh data from the source object to the container
		source->getMesh(mesh);

		// create a new ObjectMeshDynamic using the copied mesh
		ObjectMeshDynamicPtr copy = ObjectMeshDynamic::create(mesh);
	}

	return 1;
}

By passing a Mesh to an existing mesh-based object:

Get two mesh-based objects.
Create a Mesh class instance as a container.
Copy the mesh of the source mesh-based object by using the getMesh() function.
Set the copied mesh to the second mesh-based object by using the setMesh() function.

For example, you can copy the Mesh of the ObjectMeshDynamic to another existing ObjectMeshDynamic as follows:

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create ObjectMeshDynamic instances 
	ObjectMeshDynamicPtr dynamic_0 = ObjectMeshDynamic::create();
	ObjectMeshDynamicPtr dynamic_1 = ObjectMeshDynamic::create();
	// create a Mesh class instance
	MeshPtr mesh = Mesh::create();
	// copy geometry of the dynamic mesh to the Mesh class instance
	dynamic_0->getMesh(mesh);
	// put the obtained mesh to dynamic_1
	dynamic_1->setMesh(mesh);

	return 1;
}

NoticeYou can return the transformed mesh from the Mesh class to the same ObjectMeshDynamic instance without creating a new one, if necessary.

From One Mesh to Another#

You can easily copy the existing mesh instance to a new one: pass the mesh instance as an argument to the constructor as follows:

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create a source Mesh instance
	MeshPtr mesh_0 = Mesh::create("core/meshes/box.mesh");
	// pass the source mesh to the constructor of the second mesh 
	MeshPtr mesh_1 = Mesh::create(mesh_0);

	return 1;
}

Accessing Mesh Surfaces#

By using the Mesh class, you can add new surfaces to a mesh or copy surfaces from one mesh to another.

Adding a New Surface to a Mesh#

You can add a new surface to a mesh in one of the following ways:

Create a surface from scratch and then add verties and indices to it.
Create a surface using one of the existing predefined surfaces: a plane, a prism, a sphere, a box, a capsule, a cylinder, a dodecahedron, an icosahedron.

Creating a Surface from Scratch#

The Mesh class allows creating a surface and adding vertices to it.

In the following example, we create a plane by adding vertices to the mesh:

Create a Mesh class instance, add a surface and 4 vertices to it.
Add 6 indices to create a plane.
Notice
You can add indices explicitly as in the example below, or you can create indices for recently added vertices by using the createIndices() function.
Create tangents and normals by using the createTangents() and createNormals() functions.
Update bounds of the mesh to include all new vertices via the createBounds() function.
Create an ObjectMeshDynamic instance using the mesh to check the result.

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create a mesh instance
	MeshPtr mesh = Mesh::create();

	// add a new surface
	mesh->addSurface("surface_0");

	// add vertices of the plane
	mesh->addVertex(vec3(0.0f, 0.0f, 0.0f), 0);
	mesh->addVertex(vec3(0.0f, 0.0f, 1.0f), 0);
	mesh->addVertex(vec3(0.0f, 1.0f, 0.0f), 0);
	mesh->addVertex(vec3(0.0f, 1.0f, 1.0f), 0);

	// add indices 
	mesh->addIndex(0, 0);
	mesh->addIndex(1, 0);
	mesh->addIndex(2, 0);

	mesh->addIndex(3, 0);
	mesh->addIndex(2, 0);
	mesh->addIndex(1, 0);

	// create tangents
	mesh->createTangents(0);
	// create mesh bounds
	mesh->createBounds(0);
	// create normals
	mesh->createNormals(0);

	// create an ObjectMeshDynamic from the Mesh instance
	ObjectMeshDynamicPtr dynamicMesh = ObjectMeshDynamic::create(mesh);

	return 1;
}

Adding a Predefined Surface#

To add a predefined surface to a Mesh instance, use the required function. For example, to add a new capsule surface to a mesh, do the following:

Create a Mesh class instance.
Add a capsule surface via the addCapsuleSurface() function.
Create an ObjectMeshDynamic instance using the mesh to check the result.

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create a mesh instance
	MeshPtr mesh_0 = Mesh::create();
	// add a capsule surface to the mesh
	mesh_0->addCapsuleSurface("capsule_surface", 1.0f, 2.0f, 200, 100);
	// create an ObjectMeshDynamic from the Mesh instance
	ObjectMeshDynamicPtr dynamicMesh = ObjectMeshDynamic::create(mesh_0);

	return 1;
}

Copying Surfaces from One Mesh to Another#

In the following example, we create two meshes with different surfaces. The first mesh has the capsule surface, the second has the box surface. We copy the box surface from the second mesh to the first. The execution sequence is:

Create 2 instances of the Mesh class and add the capsule and box surfaces to them.
Add the box surface from the second mesh (mesh_1) to the first mesh (mesh_0) by using the addMeshSurface() function.
Create a new ObjectMeshDynamic mesh from the mesh_0 instance.

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create mesh instances
	MeshPtr mesh_0 = Mesh::create();
	MeshPtr mesh_1 = Mesh::create();

	// add surfaces for the added meshes
	mesh_0->addCapsuleSurface("capsule_surface", 1.0f, 2.0f, 200, 100);
	mesh_1->addBoxSurface("box_surface", vec3(2.2f));

	// add the surface from the mesh_1 to the mesh_0 as a new surface
	// with the name "new_box_surface"
	mesh_0->addMeshSurface("new_box_surface", mesh_1, 0);

	// create an ObjectMeshDynamic from the Mesh instance
	ObjectMeshDynamicPtr dynamicMesh = ObjectMeshDynamic::create(mesh_0);

	// set the position of the dynamic mesh
	dynamicMesh->setWorldTransform(translate(Vec3(10.0f, 10.0f, 10.0f)));

	return 1;
}

In the result, the Mesh will have 2 surfaces.

Notice

You can copy a surface from the source mesh and add it to the existing surface of the current mesh without creating a new surface by using the overloaded addMeshSurface() function.

The ObjectMeshDynamic mesh will appear in the editor:

ObjectMeshDynamic with 2 surfaces

Adding a Surface to the Existing Mesh#

In the following example, we add a surface to the existing mesh and then add necessary vertices and indices for the surface:

Create a new mesh instance from the file.
Add a new surface to the mesh.
Add vertices for the mesh surface.
Create indices for recently created vertices by using the createIndices() function.
Update bounds of the mesh to include the created surface by using the createBounds() function.
Change the surface color.

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// load a mesh from the file
	MeshPtr source_mesh = Mesh::create("core/meshes/box.mesh");

	// add a new surface
	source_mesh->addSurface("surface_triangle");

	// add 3 vertices to the new surface
	source_mesh->addVertex(vec3(-0.5f, 0.5f, 0.5f), 1);
	source_mesh->addVertex(vec3(-0.5f, -0.5f, 0.5f), 1);
	source_mesh->addVertex(vec3(-0.5f, -0.5f, 1.5f), 1);

	// create indices for the new surface
	source_mesh->createIndices(1);
	// create a new boundbox for the mesh including new surface
	source_mesh->createBounds();

	// create an ObjectMeshStatic, switch it to procedural mode and set its mesh via the source_mesh instance
	ObjectMeshStaticPtr staticMesh = ObjectMeshStatic::create();

	// before changing mesh choose Procedural Mode:
	// - Disable - procedural mode is disabled
	// - Dynamic - fastest performance, stored in RAM and VRAM, not automatically unloaded from
	// memory.
	// - Blob - moderate performance, stored in RAM and VRAM, automatically unloaded from memory.
	// - File - slowest performance, all data stored on disk, automatically unloaded from memory.
	staticMesh->setMeshProceduralMode(ObjectMeshStatic::PROCEDURAL_MODE_DYNAMIC);

	// Apply new mesh. You can do it Force or Async.
	// Changing mesh_render_flag you can choose where to store MeshRender data: in RAM or VRAM
	// 0 - store everything in VRAM (default behavior)
	// USAGE_DYNAMIC_VERTEX - store vertices on RAM
	// USAGE_DYNAMIC_INDICES - store indices on RAM
	// USAGE_DYNAMIC_ALL - store both vertices and indices on RAM
	staticMesh->applyMoveMeshProceduralAsync(source_mesh);

	staticMesh->setMaterialParameterFloat4("albedo_color", vec4(255, 255, 0, 255), 1);

	return 1;
}

The triangle surface added to the mesh:

Changing Vertex Attributes#

The Mesh class allows changing vertex attributes.

In the following example, we take a plane and change attributes of its vertices:

Create a Mesh and add a new surface to it.
Print the current normal values of 2 vertices to the console.
Set new values for the normals and print the updated values to the console.
Print the current tangent values of 2 vertices to the console.
Set new values for the tangents and print the updated values to the console.
Create a new ObjectMeshDynamic from the Mesh instance to check the result.

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create a mesh instance
	MeshPtr mesh = Mesh::create();

	// add a new surface
	mesh->addSurface("surface_0");

	// add vertices of the plane
	mesh->addVertex(vec3(0.0f, 0.0f, 0.0f), 0);
	mesh->addVertex(vec3(0.0f, 0.0f, 1.0f), 0);
	mesh->addVertex(vec3(0.0f, 1.0f, 0.0f), 0);
	mesh->addVertex(vec3(0.0f, 1.0f, 1.0f), 0);

	// add indices 
	mesh->addIndex(0, 0);
	mesh->addIndex(1, 0);
	mesh->addIndex(2, 0);

	mesh->addIndex(3, 0);
	mesh->addIndex(2, 0);
	mesh->addIndex(1, 0);

	// create tangents
	mesh->createTangents();
	// create mesh bounds
	mesh->createBounds();
	// create normals
	mesh->createNormals();

	// get the normal vectors of the 1st and the 2nd normal before changing
	vec3 normal_0 = mesh->getNormal(0, 0, 0);
	vec3 normal_1 = mesh->getNormal(1, 0, 0);
	// print values of the normals to the console
	Log::message("the first normal: %0.1f %0.1f %0.1f\n", normal_0.x, normal_0.y, normal_0.z);
	Log::message("the second normal: %0.1f %0.1f %0.1f\n",normal_1.x, normal_1.y, normal_1.z);

	// set new values for the normals
	mesh->setNormal(0, vec3(1, 1, 0), 0, 0);
	mesh->setNormal(1, vec3(1, 1, 1), 0, 0);

	// get the new normal vectors of the 1st and the 2nd normal
	vec3 new_normal_0 = mesh->getNormal(0, 0, 0);
	vec3 new_normal_1 = mesh->getNormal(1, 0, 0);
	// print values of the normals to the console
	Log::message("the first normal: %0.1f %0.1f %0.1f\n",new_normal_0.x, new_normal_0.y, new_normal_0.z);
	Log::message("the second normal: %0.1f %0.1f %0.1f\n",new_normal_1.x, new_normal_1.y, new_normal_1.z);
	// get the tangent value
	quat tangent = mesh->getTangent(0, 0, 0);
	// show the tangent value in the console
	Log::message("tangent: %0.1f %0.1f %0.1f %0.1f\n",tangent.x, tangent.y, tangent.z, tangent.w);

	// set a new value of the tangent
	mesh->setTangent(0, quat(vec3(1.0f, 0.0f, 0.0f), 20), 0, 0);

	// get the new tangent value
	quat new_tangent = mesh->getTangent(0, 0, 0);
	// show the tangent value after changing
	Log::message("tangent: %0.1f %0.1f %0.1f %0.1f\n",new_tangent.x, new_tangent.y, new_tangent.z, new_tangent.w);
	// create an ObjectMeshDynamic from the Mesh instance
	ObjectMeshDynamicPtr newDynamicMesh = ObjectMeshDynamic::create(mesh);

	// set the position of the dynamic mesh
	newDynamicMesh->setWorldTransform(translate(Vec3(1.0f, 1.0f, 1.0f)) * (Mat4)rotateZ(90.0f));

	return 1;
}

When you launch the project, in the console you'll see the following:

Output

the first normal is: -1.0 0.0 0.0 and the second is: -1.0 0.0 0.0
the first normal is: 1.0 1.0 0.0 and the second is: 1.0 1.0 1.0
tangent is: 0.5 -0.5 -0.5 0.5
tangent is: 0.2 0.0 0.0 1.0

When setTangent() and setNormal() functions were called, the normal and the tangent changed their values.

Let's comment this part of the code:

AppWorldLogic.cpp

Source code (C++)

// get the tangent value
quat tangent = mesh->getTangent(0, 0, 0);
// show the tangent value in the console
Log::message("tangent: %0.1f %0.1f %0.1f %0.1f\n",tangent.x, tangent.y, tangent.z, tangent.w);

// set a new value of the tangent
mesh->setTangent(0, quat(vec3(1.0f, 0.0f, 0.0f), 20), 0, 0);

// get the new tangent value
quat new_tangent = mesh->getTangent(0, 0, 0);
// show the tangent value after changing
Log::message("tangent: %0.1f %0.1f %0.1f %0.1f\n",new_tangent.x, new_tangent.y, new_tangent.z, new_tangent.w);

The result will be different. You can see what influence the tangent has on the vertex:


Plane with changed tangent	Plane with unchanged tangent

Creating a Primitive#

The following example shows the manual creation of a box primitive by specifying its vertices, normals and texture coordinates:

AppWorldLogic.h

Source code (C++)

/* Copyright (C) 2005-2022, UNIGINE. All rights reserved.
 *
 * This file is a part of the UNIGINE 2 SDK.
 *
 * Your use and / or redistribution of this software in source and / or
 * binary form, with or without modification, is subject to: (i) your
 * ongoing acceptance of and compliance with the terms and conditions of
 * the UNIGINE License Agreement; and (ii) your inclusion of this notice
 * in any version of this software that you use or redistribute.
 * A copy of the UNIGINE License Agreement is available by contacting
 * UNIGINE. at http://unigine.com/
 */

#ifndef __APP_WORLD_LOGIC_H__
#define __APP_WORLD_LOGIC_H__

#include <UnigineLogic.h>
#include <UnigineStreams.h>

class AppWorldLogic: public Unigine::WorldLogic
{

public:
	AppWorldLogic();
	virtual ~AppWorldLogic();

	int init() override;

	int update() override;
	int postUpdate() override;
	int updatePhysics() override;

	int shutdown() override;

	int save(const Unigine::StreamPtr &stream) override;
	int restore(const Unigine::StreamPtr &stream) override;

	void addManualBoxSurface(const Unigine::MeshPtr &mesh, const Unigine::Math::vec3 &size, const char *name);
};

#endif // __APP_WORLD_LOGIC_H__

AppWorldLogic.cpp

Source code (C++)

#include "AppWorldLogic.h"
#include <UnigineObjects.h>

using namespace Unigine;
using namespace Math;

AppWorldLogic::AppWorldLogic()
{}

AppWorldLogic::~AppWorldLogic()
{}

int AppWorldLogic::init()
{

	// create a mesh instance
	MeshPtr mesh = Mesh::create();

	// add a manually created box surface 
	addManualBoxSurface(mesh, vec3(2.0f, 2.0f, 2.0f), "box");

	// create an ObjectMeshDynamic from the Mesh instance
	ObjectMeshDynamicPtr dynamicMesh = ObjectMeshDynamic::create(mesh);

	// clear the mesh pointer
	mesh->clear();

	// set the dynamic mesh position
	dynamicMesh->setWorldTransform(translate(Math::Vec3_zero));
	// set the texture
	dynamicMesh->setMaterialTexture("albedo", "core/textures/common/checker_d.texture", 0);

	return 1;
}

void AppWorldLogic::addManualBoxSurface(const MeshPtr &mesh, const vec3 &size, const char *name)
{
	// add a new surface
	int surface_index = mesh->addSurface(name);

	// array of vertices
	const vec3 vertex[8] = {
		vec3(-0.5f, -0.5f, -0.5f), vec3(0.5f, -0.5f, -0.5f), vec3(-0.5f, 0.5f, -0.5f), vec3(0.5f, 0.5f, -0.5f),
		vec3(-0.5f, -0.5f, 0.5f), vec3(0.5f, -0.5f, 0.5f), vec3(-0.5f, 0.5f, 0.5f), vec3(0.5f, 0.5f, 0.5f) };

	// array of face normals
	const vec3 normals[6] = {
		vec3_right, vec3_left,
		vec3_forward, vec3_back,
		vec3_up, vec3_down };

	// array of texture coordinates
	const vec2 texcoords[4] = {
		vec2(1.0f, 1.0f), vec2(0.0f, 1.0f),
		vec2(0.0f, 0.0f), vec2(1.0f, 0.0f) };

	// list of indices for 6 polygons
	const int cindices[6][4] = {
		{ 3, 1, 5, 7 },{ 0, 2, 6, 4 },
		{ 2, 3, 7, 6 },{ 1, 0, 4, 5 },
		{ 6, 7, 5, 4 },{ 0, 1, 3, 2 } };

	// list of indices for a single quad made of 2 triangles
	const int indices[6] = {
		0, 3, 2, 2, 1, 0 };

	// cycle through all quads
	for (int i = 0; i < 6; i++)
	{
		// cycle through all indices of a single quad
		for (int j = 0; j < 6; j++)
		{
			int index = indices[j];
			mesh->addVertex(vertex[cindices[i][index]] * size, surface_index);
			mesh->addNormal(normals[i], surface_index);
			if (i == 4)
			{
				mesh->addTexCoord0((vec2_one - texcoords[index]), surface_index);

			}
			else
			{
				mesh->addTexCoord0(texcoords[index], surface_index);
			}
		}
	}

	// create indices per each 3 added vertices
	mesh->createIndices(surface_index);

	// create tangents
	mesh->createTangents(surface_index);

	// create mesh bounds
	mesh->createBounds(surface_index);
}

_{The information on this page is valid for UNIGINE 2.20 SDK.}

Last update: 2025-07-30

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Mesh Class

In This Article:

Mesh Structure#

Vertex Data and Indices#

Coordinate Indices#

Triangle Indices#

See Also#

Accessing a Mesh of a Mesh-Based Object#

Copying a Mesh#

From One Mesh-Based Object to Another#

From One Mesh to Another#

Accessing Mesh Surfaces#

Adding a New Surface to a Mesh#

Creating a Surface from Scratch#

Adding a Predefined Surface#

Copying Surfaces from One Mesh to Another#

Adding a Surface to the Existing Mesh#

Changing Vertex Attributes#

Creating a Primitive#