Processing 1.0 - Processing Discourse

peter666 YaBB Newbies Offline Posts: 4	Points in 3D space. Mar 3^rd, 2009, 9:07pm Help! I have a program with a big number of spheres and it needs a lot of memory. Can I substitute spheres by bold points? If I use command point(x,y); it draws a little point, but I neew bold points like little sphere. Thanks everybody!

koogy God Member Offline Posts: 788	Re: Points in 3D space. Reply #1 - Mar 4^th, 2009, 11:52am does changing the strokeWeight help? http://processing.org/reference/strokeWeight_.html

koogy God Member Offline Posts: 788	Re: Points in 3D space. Reply #2 - Mar 4^th, 2009, 11:53am koogy wrote on Mar 4^th, 2009, 11:52am: does changing the strokeWeight help http://processing.org/reference/strokeWeight_.html ellipse() might also be acceptable as a substitute (but might disappear if seen edge-on) [oops, meant to hit 'modify' rather than 'quote'. too late now.]

TVS

Re: Points in 3D space.
Reply #3 - Mar 4^th, 2009, 2:53pm

I have exactly the same problem, although even a bit worse: I do not see any points, when using

{ point(x,y,z) }

while I do see spheres, when I use

{ translate(x,y,z) and sphere(r) }

And indeed my program becomes a lot slower when using spheres...
Anybody got an idea what causes this and indeed how to solve it?

p.s. ellipse() is no option for me, exactly for the reason given by koogs (about disappearing when seeing it edge on, and I really use my program 3D, so really need to see the point/sphere always)

peter666 YaBB Newbies Offline Posts: 4	Re: Points in 3D space. Reply #4 - Mar 4^th, 2009, 3:13pm In your situation your points may have the same colour with background, and therefore you do not see them, do you?

jeffg

Re: Points in 3D space.
Reply #5 - Mar 4^th, 2009, 3:17pm

I'm also wondering how best to deal with spheres in 3d space for best performance.

One option is to use sphereDetail() and set it to below 30 (perhaps 15 or 20).

I've also seem some impressive things with numerous Vertexs (not sure if they could be used).

However, I'm wondering... depending on what your doing (it would work for me) if an ellipse can be "locked" so that it never shows an edge. Zoom in and out, rotate it around a center, and it always gives you the same face (similar to presenting text to the camera so that it never flips upside-down or backwards). I don't really need a sphere, I need the illusion of a sphere, which an ellipse might be able to do if we could prevent the edge from showing when tilted. This would also be better for applying textures to the object.

Thoughts?

TVS

Re: Points in 3D space.
Reply #6 - Mar 4^th, 2009, 3:49pm

jeffg wrote on Mar 4^th, 2009, 3:17pm:

I'm also wondering how best to deal with spheres in 3d space for best performance.

One option is to use sphereDetail() and set it to below 30 (perhaps 15 or 20).

I've also seem some impressive things with numerous Vertexs (not sure if they could be used).

However, I'm wondering... depending on what your doing (it would work for me) if an ellipse can be "locked" so that it never shows an edge. Zoom in and out, rotate it around a center, and it always gives you the same face (similar to presenting text to the camera so that it never flips upside-down or backwards). I don't really need a sphere, I need the illusion of a sphere, which an ellipse might be able to do if we could prevent the edge from showing when tilted. This would also be better for applying textures to the object.

Thoughts

Ah, the sphereDetail() hint is a good one! Thanks.

Your idea sounds good as well, although it will cause your application to even take more steps, so that might slow it down again.
Though how to exactly script it, is at this stage too time-consuming for me, since I have my thesis deadline soon, so I need all my time for that now... sorry

peter666 YaBB Newbies Offline Posts: 4	Re: Points in 3D space. Reply #7 - Mar 4^th, 2009, 7:55pm Yes, sphereDetail(); is what I actually wanted. Thank you, jeffg!

jeffg Senior Member Offline Posts: 472	Re: Points in 3D space. Reply #8 - Mar 5^th, 2009, 9:44pm If you're using OpenGL, you may want to also consider. hint(DISABLE_OPENGL_ERROR_REPORT); I found it gave a noticeable performance boost. Speeds up the OPENGL renderer setting by not checking for errors while running. Undo with hint(ENABLE_OPENGL_ERROR_REPORT).

bohnacker

Re: Points in 3D space.
Reply #9 - Mar 10^th, 2009, 11:02am

TVS wrote on Mar 4^th, 2009, 2:53pm:

p.s. ellipse() is no option for me, exactly for the reason given by koogs (about disappearing when seeing it edge on, and I really use my program 3D, so really need to see the point/sphere always)

I also had the same problem a short time ago and solved it the following way:

1.
After using pushMatrix() I did all the 3d transformations and used screenX() and screenY() to store the screen position of the points in an Array:
Code:

PVector[] screenPoints = new PVector[pointCount];
for (int i = 0; i <= pointCount; i++) {
  screenPoints[i] = new PVector(screenX(p[i].x, p[i].y, p[i].z), screenY(p[i].x, p[i].y, p[i].z));
}

2.
Reset the transformation matrix:
Code:

popMatrix();

3.
Draw the ellipses:
Code:

for (int i = 0; i < screenPoints.size(); i++) {
  PVector sp = (PVector) screenPoints.get(i);
  ellipse(sp.x, sp.y, 4, 4);
}

Of course, you don't get smaller ellipses for points that are further away, but that was ok for me.

jeffg

Re: Points in 3D space.
Reply #10 - Mar 10^th, 2009, 2:27pm

Jonathan Feinberg released a new version of PeasyCam (http://mrfeinberg.com/peasycam/) that offers a camera.getRotations() call. Using this, I was also able to use ellipses that always face the camera, instead of spheres. My frame rate went from 25 to 55. Very cool library.

Code:


float[] rotations = new float[3];
...
pushMatrix();
translate(x, y, z);
rotations = cam.getRotations();
rotateX(rotations[0]);
rotateY(rotations[1]);
rotateZ(rotations[2]);
ellipse(0,0,20,20);
popMatrix();