Example from https://learnopengl.com/Guest-Articles/2020/Skeletal-Animation:
build\Release\main.exe Capoeira_Mannequin.dae
Capoeira_Mannequin.dae comes from mixamo:
- select "Mannequin" for Characters and
- "Capoeira" for Animations.
- Download as Collada(.Dae) Format, With Skin.
Original dancing_vampire.dae from the article could be found on LearnOpenGL github.
Note on FBX and Assimp:
- FBX and Assimp embed textures; current code supports only embedded png textures.
- If there are visible issues, try different formats first (like Collada) to make sure issue is present. Try to toggle AI_CONFIG_IMPORT_FBX_PRESERVE_PIVOTS on/off.
Just CMake with VCPKG:
cmake -S . -B build ^
-DCMAKE_TOOLCHAIN_FILE=%VCPKG_ROOT%\scripts\buildsystems\vcpkg.cmake
cmake --build build --config Release
Alternatively, dependencies are (see vcpkg.json):
- ASSIMP:
vcpkg install assimp. - GLM:
vcpkg install glm. - STB:
vcpkg install stb. - GLAD:
vcpkg install glad. - GLFW:
vcpkg install glfw3.
Once installed, compile and link main.cpp with C++20 enabled.
It's possible to:
- pause animation by pressing
Spacebutton - scale model; pass
--scale 0.2to command line - change animation speed; pass
--speed 2to command line - choose different animation if file contains multiple animations; pass
--animation 3to command line - highlight part of a mesh affected by a given bone (see below)
- dump skeleton/scene hierarchy information
After Animation load, there is a dump of useful information. For instance, Capoeira_Mannequin.dae shows:
id |name |parent id |children ids |bone id |vertices |
0 |RootNode |- |1 66 |- |- |
1 |mixamorig1_Hips |0 |2 7 12 |0 |15552 |
2 |mixamorig1_RightUpLeg |1 |3 |1 |11190 |
3 |mixamorig1_RightLeg |2 |4 |32 |9681 |
4 |mixamorig1_RightFoot |3 |5 |34 |6368 |
5 |mixamorig1_RightToeBase |4 |6 |33 |4066 |
6 |mixamorig1_RightToe_End |5 |- |- |- |
7 |mixamorig1_LeftUpLeg |1 |8 |2 |11075 |
8 |mixamorig1_LeftLeg |7 |9 |9 |9681 |
9 |mixamorig1_LeftFoot |8 |10 |10 |6368 |
10 |mixamorig1_LeftToeBase |9 |11 |11 |4066 |
11 |mixamorig1_LeftToe_End |10 |- |- |- |
12 |mixamorig1_Spine |1 |13 |12 |7694 |
13 |mixamorig1_Spine1 |12 |14 |8 |12296 |
14 |mixamorig1_Spine2 |13 |15 39 63 |7 |15570 |
15 |mixamorig1_RightShoulder |14 |16 |30 |5221 |
16 |mixamorig1_RightArm |15 |17 |31 |6411 |
17 |mixamorig1_RightForeArm |16 |18 |35 |3979 |
18 |mixamorig1_RightHand |17 |19 23 27 31 35 |36 |4642 |
19 |mixamorig1_RightHandPinky1 |18 |20 |47 |2187 |
20 |mixamorig1_RightHandPinky2 |19 |21 |48 |1581 |
21 |mixamorig1_RightHandPinky3 |20 |22 |49 |1008 |
22 |mixamorig1_RightHandPinky4 |21 |- |- |- |
23 |mixamorig1_RightHandRing1 |18 |24 |44 |1652 |
24 |mixamorig1_RightHandRing2 |23 |25 |45 |1501 |
25 |mixamorig1_RightHandRing3 |24 |26 |46 |654 |
26 |mixamorig1_RightHandRing4 |25 |- |- |- |
27 |mixamorig1_RightHandMiddle1 |18 |28 |37 |1485 |
28 |mixamorig1_RightHandMiddle2 |27 |29 |40 |1493 |
29 |mixamorig1_RightHandMiddle3 |28 |30 |39 |1008 |
30 |mixamorig1_RightHandMiddle4 |29 |- |- |- |
31 |mixamorig1_RightHandIndex1 |18 |32 |43 |1521 |
32 |mixamorig1_RightHandIndex2 |31 |33 |41 |1581 |
33 |mixamorig1_RightHandIndex3 |32 |34 |42 |1134 |
34 |mixamorig1_RightHandIndex4 |33 |- |- |- |
35 |mixamorig1_RightHandThumb1 |18 |36 |38 |1738 |
36 |mixamorig1_RightHandThumb2 |35 |37 |50 |1730 |
37 |mixamorig1_RightHandThumb3 |36 |38 |51 |1067 |
38 |mixamorig1_RightHandThumb4 |37 |- |- |- |
39 |mixamorig1_LeftShoulder |14 |40 |6 |5181 |
40 |mixamorig1_LeftArm |39 |41 |5 |6411 |
41 |mixamorig1_LeftForeArm |40 |42 |13 |3979 |
42 |mixamorig1_LeftHand |41 |43 47 51 55 59 |14 |4642 |
43 |mixamorig1_LeftHandPinky1 |42 |44 |22 |2187 |
44 |mixamorig1_LeftHandPinky2 |43 |45 |25 |1581 |
45 |mixamorig1_LeftHandPinky3 |44 |46 |26 |1008 |
46 |mixamorig1_LeftHandPinky4 |45 |- |- |- |
47 |mixamorig1_LeftHandRing1 |42 |48 |23 |1652 |
48 |mixamorig1_LeftHandRing2 |47 |49 |24 |1501 |
49 |mixamorig1_LeftHandRing3 |48 |50 |27 |654 |
50 |mixamorig1_LeftHandRing4 |49 |- |- |- |
51 |mixamorig1_LeftHandMiddle1 |42 |52 |18 |1485 |
52 |mixamorig1_LeftHandMiddle2 |51 |53 |16 |1493 |
53 |mixamorig1_LeftHandMiddle3 |52 |54 |17 |1008 |
54 |mixamorig1_LeftHandMiddle4 |53 |- |- |- |
55 |mixamorig1_LeftHandIndex1 |42 |56 |21 |1521 |
56 |mixamorig1_LeftHandIndex2 |55 |57 |20 |1581 |
57 |mixamorig1_LeftHandIndex3 |56 |58 |19 |1134 |
58 |mixamorig1_LeftHandIndex4 |57 |- |- |- |
59 |mixamorig1_LeftHandThumb1 |42 |60 |15 |1738 |
60 |mixamorig1_LeftHandThumb2 |59 |61 |28 |1730 |
61 |mixamorig1_LeftHandThumb3 |60 |62 |29 |1067 |
62 |mixamorig1_LeftHandThumb4 |61 |- |- |- |
63 |mixamorig1_Neck |14 |64 |4 |2446 |
64 |mixamorig1_Head |63 |65 |3 |6348 |
65 |mixamorig1_HeadTop_End |64 |- |- |- |
66 |Ch36 |0 |- |- |- |
where id is an id of an Assimp' scene Node (not an animation bone/joint). bone id
is an internal index of a bone/joint used by vertex shader to transform vertices. vertices column shows the amount of vertices affected by a given bone/joint/node.
Vertex shader in main.cpp has int debug_bone_id = -1 config. Setting it to an existing bone, like 8 for mixamorig1_Spine1 above will highlight part of a mesh affected by a given bone:
(Not submitted). Render joints/bones as (red) points:
// Animation::update().
std::vector<glm::mat4> _nodes_transforms;
_nodes_transforms[bone_index] = _global_inverse * node.transform;
// Render.
render_points._points.clear();
for (glm::mat4 m : animation.nodes_transforms())
{
const glm::vec4 p = m * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
render_points._points.push_back(glm::vec3(p / p.w));
}
glDisable(GL_DEPTH_TEST);
render_points.draw(mvp);
glEnable(GL_DEPTH_TEST);
