8.6 、为旗杆增加布 我想要让 flag 看起来像 很好,像 flag 。为了这么做,我们需要模拟一个布的 flag , attach 到旗杆。有什么更好的方式完成这件事,还是使用 jme 的 clothpatch 功能。这将允许我们去创建一个弹簧( spring )点的 matrix ,它们由不同方
8.6、为旗杆增加布 我想要让flag看起来像…很好,像flag。为了这么做,我们需要模拟一个布的flag,attach到旗杆。有什么更好的方式完成这件事,还是使用jme的clothpatch功能。这将允许我们去创建一个弹簧(spring)点的matrix,它们由不同方向的外力(force)调整(引力和风力)。我已经为这个向导创建了我自己的风力,而我们将在下面讨论。
首先,增加对象到flag类。
//用于制作flag的cloth
private clothpatch cloth;
//风的参数
privatefloatwindstrength = 15f;
private vector3f winddirection = new vector3f(0.8f, 0, 0.2f);
private springpointforce gravity,wind;
在flag的构造参数中,我们将创建一个clothpatch。这个cloth将是25*25的matrix,给它一个相当详细的cloth。cloth上的点越多,它运行得越慢,所以你应该在flag的视觉外观和它对游戏的影响之间选个平衡点。25*25给我一个可接受的性能和外观的比例。在创建cloth之后,我们将增加我们的force。我们增加的第一个force是我们为这个向导创建的自定义的force,叫做randomflagwindforce。我们也将增加一个默认的重力它是由clothutils创建的,这将在风减小的时候把flag拉下来。
//创建一个cloth patch 将处理我们flag
cloth = new clothpatch(cloth, 25, 25, 1f, 10);
//将我们自定义的风力增加到cloth
wind = new randomflagwindforce(windstrength, winddirection);
cloth.addforce(wind);
//增加一个简单的重力
gravity = clothutils.createbasicgravity();
cloth.addforce(gravity);
由于cloth是标准的jme spatial,我们和平常一样应用renderstate。我们将为flag增加texture,使用jme monkey的logo。这个是一个让monkey的头在你脑海留下烙印的企图。
//创建一个将flag显示的texture,一起推进jme发展!
texturestate ts = displaysystem.getdisplaysystem()
.getrenderer().createtexturestate();
ts.settexture(
texturemanager.loadtexture(
flag.class.getclassloader()
.getresource(res/logo.png),
texture.minificationfilter.trilinear,
texture.magnificationfilter.bilinear
)
);
cloth.setrenderstate(ts);
当我开始增加一个flag到场景时,我对light非常不满意,因为flag大部分时间都是阴影。因此,我决定增加一个light,它只影响flag。这个light应该跟着flag移动,并且根据flag定位自己。因此,使用一个lightnode是最好的解决方案。lightnode允许你对待一个light就像scene中的其它元素一样,通过移动light的父亲node移动它。
//我们将使用一个lightnode去给flag增加light,使用node
//是因为它允许light随着flag移动
//首先创建light
pointlight dr = new pointlight();
dr.setenabled(true);
dr.setdiffuse(new colorrgba(1.0f, 1.0f, 1.0f, 1.0f));
dr.setambient(new colorrgba(0.5f, 0.5f, 0.5f, 1.0f));
dr.setlocation(new vector3f(0.5f, -0.5f, 0));
//接下来是state
lightstate lightstate = displaysystem.getdisplaysystem()
.getrenderer().createlightstate();
lightstate.setenabled(true);
lightstate.settwosidedlighting(true);
lightstate.attach(dr);
setrenderstate(lightstate);
//最后是结点
lightnode lightnode = new lightnode(light);
lightnode.setlight(dr);
lightnode.setlocaltranslation(new vector3f(15,0,0));
attachchild(lightnode);
cloth.setrenderstate(lightstate);
flag有一点和前面不同,那就是我们想看到它所有面的三角形。前面,我们设置了scene的cullstate去剔除所有背后的三角形。因此,我们将增加另一个cullstate给cloth,让它不要剔除任何三角形。它将看到所有的三角形。
//我们想看flag所有的面,所以我们将关闭cull
cullstate cs = displaysystem.getdisplaysystem()
.getrenderer().createcullstate();
cs.setcullface(cullstate.face.none);
cloth.setrenderstate(cs);
this.attachchild(cloth);
下一步,我们需要为cloth创建一些点去固定它。如果我们不这么做,整个cloth将在force应用于它身上时被“吹走”。我们需要在旗杆上attach一些点去保住cloth。我们通过设置点的质量为无穷大来这么做。因此,没有任何force能移走它。为了模拟这个方法,一个flag被attach到一个旗杆,flag上边缘的一些和旗杆接触的点将被attach,下面的也是。这些点被设置在一个基础的二维matrix中,所以我们将attach点(0,1,2,3,4)到旗杆,点(500,525,550,575,600)也一样。我们也调整这些点在y的位置让它们偏移,从而让cloth形成一点褶皱。
//我们需要attach一些点到旗杆,这些点不应该被移动。
//因此,我们将attach顶部和底部的5个点去让它们足够高而
//且没有任何forece能移动它。我也稍微移动这些点的位置去
//形成褶皱让它更真实。
for(int i=0; i
cloth.getsystem().getnode(i*25).position.y *= .8f;
cloth.getsystem().getnode(i*25)
.setmass(float.positive_infinity);
}
for(int i=24; i>19; i--){
cloth.getsystem().getnode(i*25).position.y *= .8f;
cloth.getsystem().getnode(i*25)
.setmass(float.positive_infinity);
}
最后,我创建自定义风力。为了模仿旗杆上flag的效果,我们也随机化风向。风向将基于它之前的位置
/**
* 在每次update cloth时调用。将轻微调整风向和强度、
*/
publicvoid apply(float dt, springpoint node) {
winddirection.x += dt * (fastmath.nextrandomfloat() - .5f);
winddirection.z += dt * (fastmath.nextrandomfloat() - .5f);
winddirection.normalize();
float tstr = fastmath.nextrandomfloat() * strength;
node.acceleration.addlocal(
winddirection.x * tstr,
winddirection.y * tstr,
winddirection.z * tstr
);
}
通过那样,我们现在有一个看起来真实的flag,而且我们以自己的方式去为我们游戏中添加元素。下一课,我们只需能获取flag。
8.7、源码
import java.io.ioexception;
import java.net.url;
import java.util.hashmap;
import javax.swing.imageicon;
import com.jme.app.basegame;
import com.jme.bounding.boundingbox;
import com.jme.image.texture;
import com.jme.input.chasecamera;
import com.jme.input.inputhandler;
import com.jme.input.keybindingmanager;
import com.jme.input.keyinput;
import com.jme.input.thirdperson.thirdpersonmouselook;
import com.jme.light.directionallight;
import com.jme.math.fastmath;
import com.jme.math.vector3f;
import com.jme.renderer.camera;
import com.jme.renderer.colorrgba;
import com.jme.renderer.renderer;
import com.jme.scene.node;
import com.jme.scene.skybox;
import com.jme.scene.shape.box;
import com.jme.scene.state.cullstate;
import com.jme.scene.state.lightstate;
import com.jme.scene.state.texturestate;
import com.jme.scene.state.zbufferstate;
import com.jme.system.displaysystem;
import com.jme.system.jmeexception;
import com.jme.util.texturemanager;
import com.jme.util.timer;
import com.jme.util.export.binary.binaryimporter;
import com.jmex.model.converters.maxtojme;
import com.jmex.terrain.terrainblock;
import com.jmex.terrain.util.midpointheightmap;
import com.jmex.terrain.util.proceduraltexturegenerator;
publicclass lesson8 extends basegame{
privateintwidth,height;
privateintfreq,depth;
privatebooleanfullscreen;
//我们的camera对象,用于观看scene
private camera cam;
protected timer timer;
private node scene;
private texturestate ts;
private terrainblock tb;
private forcefieldfence fence;
private skybox skybox;
private vehicle player;
private chasecamera chaser;
private inputhandler input;
//保存terrain的任何一个给出点的法向
private vector3f normal = new vector3f();
privatefloatagl;
private flag flag;
publicstaticvoid main(string[] args) {
lesson8 app = new lesson8();
java.net.url url = app.getclass().getclassloader().getresource(res/logo.png);
app.setconfigshowmode(configshowmode.alwaysshow,url);
app.start();
}
/*
* 清除texture
*/
protectedvoid cleanup() {
ts.deleteall();
}
protectedvoid initgame() {
display.settitle(flag rush);
scene = new node(scene graph node);
zbufferstate buf = display.getrenderer().createzbufferstate();
buf.setenabled(true);
buf.setfunction(zbufferstate.testfunction.lessthanorequalto);
scene.setrenderstate(buf);
buildterrain();
buildflag();
buildlighting();
buildenvironment();
createskybox();
buildplayer();
buildchasecamera();
buildinput();
cullstate cs = display.getrenderer().createcullstate();
cs.setcullface(cullstate.face.back);
scene.setrenderstate(cs);
//更新scene用于渲染
scene.updategeometricstate(0.0f, true);
scene.updaterenderstate();
}
privatevoid buildflag() {
flag = new flag(tb);
scene.attachchild(flag);
flag.placeflag();
}
privatevoid buildinput() {
input = new flagrushinputhandler(
player,
settings.getrenderer()
);
}
privatevoid buildchasecamera() {
hashmap props = new hashmap();
props.put(thirdpersonmouselook.prop_maxrollout, 6);
props.put(thirdpersonmouselook.prop_minrollout, 3);
props.put(
thirdpersonmouselook.prop_maxascent,
+45*fastmath.deg_to_rad
);
props.put(
chasecamera.prop_initialspherecoords,
new vector3f(5,0,30*fastmath.deg_to_rad)
);
chaser = new chasecamera(cam, player, props);
chaser.setmaxdistance(8);
chaser.setmindistance(2);
}
privatevoid buildplayer() {
node model = null;
url maxfile = lesson8.class.getclassloader()
.getresource(res/bike.jme);
try {
model = (node)binaryimporter.getinstance().load(
maxfile.openstream()
);
model.setmodelbound(new boundingbox());
model.updatemodelbound();
model.setlocalscale(0.0025f);
} catch (ioexception e1) {
e1.printstacktrace();
}
//设置vehicle的属性(这些数字能被认为是单元/秒 unit/s)
player = new vehicle(player node,model);
player.setacceleration(15);
player.setbraking(25);
player.setturnspeed(2.5f);
player.setweight(25);
player.setmaxspeed(25);
player.setminspeed(15);
player.setlocaltranslation(new vector3f(100,0, 100));
player.updateworldbound();
player.setrenderqueuemode(renderer.queue_opaque);
scene.attachchild(player);
scene.updategeometricstate(0, true);
agl = ((boundingbox)(player.getworldbound())).yextent;
}
privatevoid createskybox() {
skybox = new skybox(skybox,10,10,10);
texture north = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/north.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
texture south = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/south.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
texture east = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/east.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
texture west = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/west.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
texture up = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/top.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
texture down = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/texture/bottom.jpg),
texture.minificationfilter.bilinearnearestmipmap,
texture.magnificationfilter.bilinear
);
skybox.settexture(skybox.face.north, north);
skybox.settexture(skybox.face.west, west);
skybox.settexture(skybox.face.south, south);
skybox.settexture(skybox.face.east, east);
skybox.settexture(skybox.face.up, up);
skybox.settexture(skybox.face.down, down);
skybox.preloadtextures();
scene.attachchild(skybox);
}
privatevoid buildenvironment() {
fence = new forcefieldfence(forcefieldfence);
//我们将手工做一些调整去让它更好适应terrain
//首先我们将实体“模型”放大
fence.setlocalscale(5);
//现在,让我们移动fence到terrain的高度并有一点陷入它里面
fence.setlocaltranslation(
new vector3f(25,tb.getheight(25,25)+10,25)
);
scene.attachchild(fence);
}
privatevoid buildlighting() {
/* 设置一个基础、默认灯光 */
directionallight light = new directionallight();
light.setdiffuse(new colorrgba(1.0f, 1.0f, 1.0f, 1.0f));
light.setambient(new colorrgba(0.5f, 0.5f, 0.5f, 1.0f));
light.setdirection(new vector3f(1, -1, 0));
light.setenabled(true);
lightstate lightstate = display.getrenderer().createlightstate();
lightstate.setenabled(true);
lightstate.attach(light);
scene.setrenderstate(lightstate);
}
/**
* 创建heightmap和terrainblock
*/
privatevoid buildterrain() {
//生成随机地形数据
midpointheightmap heightmap = new midpointheightmap(64,1f);
//缩放数据
vector3f terrainscale = new vector3f(4, .0575f, 4);
//创建一个terrain block
tb = new terrainblock(
terrain,
heightmap.getsize(),
terrainscale,
heightmap.getheightmap(),
new vector3f(0, 0, 0)
);
tb.setmodelbound(new boundingbox());
tb.updatemodelbound();
//通过三个纹理生成地形纹理
proceduraltexturegenerator pt =
new proceduraltexturegenerator(heightmap);
pt.addtexture(
new imageicon(
getclass().getclassloader()
.getresource(res/grassb.png)
),
-128, 0, 128
);
pt.addtexture(
new imageicon(
getclass().getclassloader()
.getresource(res/dirt.jpg)
),
0, 128, 256
);
pt.addtexture(
new imageicon(
getclass().getclassloader()
.getresource(res/highest.jpg)
),
128, 256, 384
);
pt.createtexture(32);
//将纹理赋予地形
ts = display.getrenderer().createtexturestate();
texture t1 = texturemanager.loadtexture(
pt.getimageicon().getimage(),
texture.minificationfilter.trilinear,
texture.magnificationfilter.bilinear,
true
);
ts.settexture(t1, 0);
//加载细节纹理并为2个terrain的texture设置组合模型
texture t2 = texturemanager.loadtexture(
lesson8.class.getclassloader()
.getresource(res/detail.jpg),
texture.minificationfilter.trilinear,
texture.magnificationfilter.bilinear
);
ts.settexture(t2, 1);
t2.setwrap(texture.wrapmode.repeat);
t1.setapply(texture.applymode.combine);
t1.setcombinefuncrgb(texture.combinerfunctionrgb.modulate);
t1.setcombinesrc0rgb(texture.combinersource.currenttexture);
t1.setcombineop0rgb(texture.combineroperandrgb.sourcecolor);
t1.setcombinesrc1rgb(texture.combinersource.primarycolor);
t1.setcombineop1rgb(texture.combineroperandrgb.sourcecolor);
t2.setapply(texture.applymode.combine);
t2.setcombinefuncrgb(texture.combinerfunctionrgb.addsigned);
t2.setcombinesrc0rgb(texture.combinersource.currenttexture);
t2.setcombineop0rgb(texture.combineroperandrgb.sourcecolor);
t2.setcombinesrc1rgb(texture.combinersource.previous);
t2.setcombineop1rgb(texture.combineroperandrgb.sourcecolor);
tb.setrenderstate(ts);
tb.setdetailtexture(1, 16);
tb.setrenderqueuemode(renderer.queue_opaque);
scene.attachchild(tb