Useful Tools for Making Video Games

Part IAn overview of Ogre

Sample Games

Thunder Wheels Kong Masterplan Pacific Storm Trampoline

Features

Graphics API independent 3D implementation Platform independence Material & Shader support

Well known texture formats: png, jpeg, tga, bmp, dds, dxt Mesh support: Milkshape3D, 3D Studio Max, Maya,

Blender Scene features

BSP, Octree plugins, hierarchical scene graph Special effects

Particle systems, skyboxes, billboarding, HUD, cube mapping, bump mapping, post-processing effects

Easy integration with physics libraries ODE, Tokamak, Newton, OPCODE

Open source!

Core Objects

Startup Sequence

ExampleApplication Go() Setup() Configure() setupResources() chooseSceneManager() createCamera() createViewport() createResourceListener() loadResources() createScene() frameStarted/Ended() createFrameListener() destroyScene()

Basic Scene

Entity, SceneNode Camera, lights, shadows BSP map Integrated ODE physics BSP map Frame listeners

Terrain, sky, fog

CEGUI Window, panel, scrollbar,

listbox, button, static text Media/gui/ogregui.layoutCEGUI::Window* sheet = CEGUI::WindowManager::getSingleton().load

WindowLayout( (CEGUI::utf8*)"ogregui.layout");

mGUISystem->setGUISheet(sheet);

Animation

Node animation (camera, light sources) Skeletal Animation

AnimationState *mAnimationState; mAnimationState = ent-

>getAnimationState("Idle");mAnimationState->setLoop(true);mAnimationState->setEnabled(true); mAnimationState-

>addTime(evt.timeSinceLastFrame); mNode->rotate(quat);

Animation

Crowd (instancing vs single entity)InstancedGeometry* batch = new InstancedGeometry(mCamera-

>getSceneManager(), "robots" );batch->addEntity(ent, Vector3::ZERO);batch->build();

Facial animationVertexPoseKeyFrame* manualKeyFrame;manualKeyFrame->addPoseReference();manualKeyFrame->updatePoseReference ( ushort

 poseIndex, Real influence) 

Picking

Picking

CEGUI::Point mousePos = CEGUI::MouseCursor::getSingleton().getPosition(); Ray mouseRay = mCamera->getCameraToViewportRay(mousePos.d_x/float(arg.state.width), mousePos.d_y/float(arg.state.height)); mRaySceneQuery->setRay(mouseRay); mRaySceneQuery->setSortByDistance(false); RaySceneQueryResult &result = mRaySceneQuery->execute(); RaySceneQueryResult::iterator mouseRayItr; Vector3 nodePos; for (mouseRayItr = result.begin(); mouseRayItr != result.end();

mouseRayItr++) { if (mouseRayItr->worldFragment) { nodePos = mouseRayItr->worldFragment->singleIntersection; break; } // if }

Particle EffectsmSceneMgr->getRootSceneNode()->createChildSceneNode()->attachObject(

mSceneMgr->createParticleSystem("sil", "Examples/sil"));

Examples/sil{ material Examples/Flare2 particle_width 75 particle_height 100 cull_each false quota 1000 billboard_type oriented_self // Area emitter emitter Point { angle 30 emission_rate 75 time_to_live 2 direction 0 1 0 velocity_min 250 velocity_max 300 colour_range_start 0 0 0 colour_range_end 1 1 1 }

// Gravity affector LinearForce { force_vector 0 -100 0 force_application add }

// Fader affector ColourFader { red -0.5 green -0.5 blue -0.5 }}

Particle Effects

Particle system attributesquota material particle_width particle_height cull_each billboard_type billboard_origin billboard_rotation_type common_direction common_up_vector renderer sorted local_space point_rendering accurate_facing iteration_interval

nonvisible_update_timeout

Emitter attributes(point, box, clyinder, ellipsoid, hollow ellipsoid, ring)angle colour colour_range_start colour_range_end direction emission_rate position velocity velocity_min velocity_max time_to_live time_to_live_min time_to_live_max duration duration_min duration_max repeat_delay repeat_delay_min repeat_delay_max

Affectors (LinearForce, ColorFader)Linear Force Affector ColourFader Affector ColourFader2 Affector Scaler Affector Rotator Affector ColourInterpolator Affector ColourImage Affector DeflectorPlane Affector DirectionRandomiser Affector

Fire and Smoke

affector Rotator { rotation_range_start 0 rotation_range_end 360 rotation_speed_range_start -60 rotation_speed_range_end

200 }

Cel Shading

vertex_program Ogre/CelShadingVP cg{

source Example_CelShading.cgentry_point main_vp…

default_params{… }

}

material Examples/CelShading{…

vertex_program_ref Ogre/CelShadingVP {}fragment_program_ref Ogre/CelShadingFP {}

}

Cube Mapping

With Perlin noise to distort vertices

void morningcubemap_fp (float3 uv : TEXCOORD0,out float4 colour : COLOR,uniform samplerCUBE tex : register(s0) )

{colour = texCUBE(tex, uv);// blow out the light a bitcolour *= 1.7;

}

Bump Mapping

+ =

Reflections & Refractions// Noisetexture_unit{

// Perlin noise volumetexture waves2.dds// min / mag filtering, no mipfiltering linear linear none

}// Reflectiontexture_unit{ // Will be filled in at runtime

texture Reflectiontex_address_mode clamp// needed by ps.1.4tex_coord_set 1

}// Refractiontexture_unit{

// Will be filled in at runtimetexture Refractiontex_address_mode clamp// needed by ps.1.4tex_coord_set 2

}

Reflections & Refractions

Grass

Each grass section is 3 planes at 60 degrees to each otherNormals point straight up to simulate correct lighting

Post-Processing Effects

Supporting tools (add-ons)

Blender, Autodesk 3DS, Milkshape3D, Softimage XSI importers/exporters

Particle editors, mesh viewers GUI editors Physics bindings Scene exporters and lots moreAdd-on site

References

http://www.ogre3d.org/