I''m trying to get a animated billboard of an expolosion working. Does anyone know of one?

Hi there!

I have a billboard tutorial that can be useful to you (But the demos are in DirectX 7.0). Anyway, the theory is cool.

Feel free to email me at gameover@vtr.net, so I can mail it to u.

[edited by - GameOverCL on December 22, 2003 11:04:17 PM]

Err... Why don''t you look up a regular billboarding tutorial (which shouldn''t have more than 10-20 lines of code) and add an animated texture to it (update the texture every n milliseconds or so). Nothing fancy...

---

I may just be youre Santa Clause this year...
Here`s some billboarding code ->

void ResetMatrix(){//probably the key to everything	float modelview[16];	int i,j;	glGetFloatv(GL_MODELVIEW_MATRIX,modelview);	for( i=0; i<3; i++ ) 	    for( j=0; j<3; j++ ) {		if ( i==j )//unrotate the modelview matrix->		    modelview[i*4+j] = 1.0;//always face camera		else		    modelview[i*4+j] = 0.0;	    }	glLoadMatrixf(modelview);}/************/void Render(){glPushMatrix();glTranslatefv(ObjectPosition);glPushMatrix();ResetMatrix();//glRotatef(SomeRotationhere,0,0,1);//rotate on z axis//Render youre object here->glPopMatrix();glPopMatrix();

And that`s about it... animating will be pretty much simple but that`s the hard code that no one knows

why all that reset code??

why not just call glLoadIdentity(); ??

Because glLoadIdentity resets rotation, scaling and translation, while cippyboy''s code effectively resets rotation (and scaling? - haven''t fully worked this through yet), leaving the translation part of the matrix intact. It looks like a neat way of doing things, but I''m not sure how robust it is (i.e. scaling e.t.c).

Enigma

First of all it`s not me to be thanked.. I took from some site and now I`m angered because I forgot from where I took it
but I remodeled some of it to fit for my needs, and offcourse I thought of scaling as well.
here`s a new piece of code that can effectively render a scaled particle->

void PARTICLE_SYSTEM::Render_SizedParticle(PARTICLE *MyParticle,int TID,float size){glPushMatrix();glTranslatef(MyParticle->Pos.x,MyParticle->Pos.y,MyParticle->Pos.z);glPushMatrix();ResetMatrix();glRotatef(MyParticle->rot,0,0,1);//rotate for variations and suchglActiveTextureARB(GL_TEXTURE1_ARB);glDisable(GL_TEXTURE_2D);glActiveTextureARB(GL_TEXTURE0_ARB);glEnable(GL_TEXTURE_2D);glBindTexture(GL_TEXTURE_2D,TID);glColor4f(MyParticle->Color.x,MyParticle->Color.y,MyParticle->Color.z,MyParticle->life);glBegin(GL_QUADS);glNormal3f(0.0f,0.0f,1.0f);//I don`t know how good the normalsglMultiTexCoord2fARB(GL_TEXTURE0_ARB,0.0f,0.0f);//are though...glVertex3f(-size,-size,0.0f);//but I`d recommend no lighting onglNormal3f(0.0f,0.0f,1.0f);//themglMultiTexCoord2fARB(GL_TEXTURE0_ARB,1.0f,0.0f);glVertex3f(size,-size,0.0f);glNormal3f(0.0f,0.0f,-1.0f);glMultiTexCoord2fARB(GL_TEXTURE0_ARB,1.0f,1.0f);glVertex3f(size,size,0.0f);glNormal3f(0.0f,0.0f,-1.0f);glMultiTexCoord2fARB(GL_TEXTURE0_ARB,0.0f,1.0f);glVertex3f(-size,size,0.0f);glEnd();glPopMatrix();glPopMatrix();}

Just wanted to thank everyone that helped, I wass able to get it working correctly. Now I just need to get the actual pictures to appear.

Ok, here's another problem. After I got the billboard to always face the player, I started to try to get the picture to work correctly, but I can't seem to figure out what the farg is wrong with my system.

Here's my code:

bool EXPLOSION::ExplosionInit(GLvoid)	{	float cx=0;	float cy=0;	float loopx,loopy,padx,pady;	int loop = 0;	if (!file.LoadTGAFile("Art\\explosion1.tga"))//, GL_LINEAR, GL_LINEAR))		return false;	boom=glGenLists(64);						//Creating a display list that can hold 64	glBindTexture(GL_TEXTURE_2D, file.ID);		//Bind our explosion texture	padx = (1/(float)file.imageWidth)*32;	pady = (1/(float)file.imageHeight)*32;	loopx = (1/(float)file.imageWidth)*31;	loopy = (1/(float)file.imageHeight)*31;	for(cy=0.0f; cy<file.imageHeight; cy+=pady)				//Loop through the display list	{		for(cx=0.0f; cx<file.imageWidth; cx+=padx)		{			glNewList(boom+loop,GL_COMPILE);		//Start building a list				glBegin(GL_TRIANGLE_STRIP);			//Use a quad for each character					//Top right (tex/vertex) coordinates					glTexCoord2f( (cx+loopx),	(cy+loopy));	glVertex2f(1.0f,1.0f);					//Top left (tex/vertex) coordinates					glTexCoord2f( (cx),		(cy+loopy));	glVertex2f(0.0f,1.0f);					//Bottom right (tex/vertex) coordinates					glTexCoord2f( (cx+loopx),	(cy));		glVertex2f(1.0f,0.0f);					//Bottom left (tex/vertex) coordinates					glTexCoord2f( (cx),		(cy));		glVertex2f(0.0f,0.0f);					glEnd();							//Done Building Our Quad (Character)			glEndList();							//Done Building The Display List			loop++;		}	}										// Loop Until All 64 Are Built	return true;}

The pic I'm using is a 256x256 targa with 64 animation screens at 32x32 each.

Now I've been playing around with this for some time and I am about ready to scrap it altogether and start fresh, for the 10th time.

If anyone, and I mean anyone has any ideas of what I'm doing wrong, PLEASE tell me.

[edited by - Steelrose on December 26, 2003 11:36:01 PM]

Check your for-loops. The test is wrong (they loop too many times). Also your triangle strips are wrong - swap the order of the last two vertices. Also you shouldn't need loopx and loopy - just use padx and pady - unless you have a border between animation frames in your image.

Enigma

EDIT: triangle strips were correct - don't know what I was thinking!

[edited by - Enigma on December 28, 2003 8:13:52 AM]