How to blur 3d object? (Papervision 3d) And save created new object as new 3d model? (can help in sky/clouds generation)
Like in 2d picture I've turn rectangel intu some blury structure
(source: narod.ru)
Set useOwnContainer to true the add the filter:
your3DObject.useOwnContainer = true;
your3DObject.filters = [new BlurFilter(4,4,2)];
When you set useOwnContainer to true, a new 2d DisplayObject is created to render the 3d projection into, and you can apply of the usual DisplayObject properties to that.
Andy Zupko has a good post about this and render layers.
Using this will cost your processor a bit, so use it wisely. For example
in the twigital I worked on at disturb media we used one Glow for
the layer that holds all the characters, not inidividual render layers for each
character. On other projects we 'baked' the filters into bitmaps and used them,
this meant a bit more memory, but freed up the processor a bit for other tasks.
HTH
I'm not familiar with Papervision 3D, but blurring in 3D is normally just blurring in 2D. You pick the object you want blurred, determine the blurring you want for that object, then apply a 2D blur before compositing other objects into the scene.
This is a cheat because in principle, different parts of the object may need different degrees of (depth of field) blurring. But it's not the only cheat in 3D graphics.
That said, there are other approaches. Ray-tracing can give true depth-of-field effects (if you're willing to pay the render-time costs). It's also possible to apply a blur to a 3D "voxel" grid instead of a 2D pixel grid - though I imagine that's more useful for smoothing shapes from e.g. medical scanners than for giving depth-of-field effects.
Blur is 2D operation, try to render object into texture and blur that texture.
Related
I'm looking to auto-generate a UML class model in virtual reality using A-Frame.io (or another technology) by passing in values. Has anyone ever done something similar in the past? Not sure where to start.
Thanks
You might want to look into plantuml which is a nice UML generator. Most of it's diagrams are generated as input to graphviz's dot. Dot is a layout engine - it takes a list of nodes and connections and puts them into 2D space and then renders them to one of it's output formats - or just returns the graph, but this time with coordinates on where to draw what. You could meddle with this data and render the elements with volume but on a 2D plane with dot generated coordinates. Perhaps even you could modify it to place them in 3D space instead of a plane.
Or you could just render the plantuml output on a 2D plane, place it in 3D space and it would probably be good enough. There are even online generators for plantuml.
I'm currently rendering a 3D model (Wavefront .obj format) in my Qt program. Right now, I'm rendering the model using Scene3D in QML, and I'm able to get it to display in the viewing area. What I would like to do is have a user click on the model and generate a 2D cross section of the slice that I would like to plot on a different window. I'm quite new to 3D rendering, and a lot of Qt documentation isn't very descriptive. I've been reading Qt documentation, experimenting, and searching online with no luck. How can I create 2D slices of a 3D object Model in Qt 3D, preferably in QML? What Qt libraries or classes can I use to achieve this?
Unfortunately, the fact that models are stored as a set of surfaces makes this hard. QT probably doesn't have a built in method for this.
Consider, for example, that a model made of faces might be missing a face. What now? can you interpolate across that gap consistently from different angles? What about the fact that a cross-section probably won't contain any vertices?
But, of course, it can be solved. First, just don't allow un-closed surfaces (meshes with holes). Second, for finding the vertices of your cross-section, perform an intersection between every edge in your model and the plane you're using, and if there's an intersection, there's a point there. Third, to find the edges, look at the list of vertices, and any two that are from an edge on the same polygon in the mesh should be connected by an edge in the cross section. To find which direction the edge should go, project the normal of the polygon onto the plane your using. For filling, I don't really know what to do. I guess that's whatever you want it to be.
I know that if I rotate an object, which extends javafx.scene.shape.Shape, I can transform it into 3D space, even though it was primarily designed to be in 2D (at least as far as I know).
Let's say I have a 3D scene (perspective camera and depth buffer are used), where various MeshViews occur. Some are used for areas, others for lines. In both cases those shapes must be triangulated in order to draw them with a TriangleMesh, which is often nontrivial.
Now when I change the drawing of these lines to use the Polyline class, the performance collapse is horrible and there a strange artefacts. I thought I could benefit from the fact, that a polyline has less vertices and the developer doesn't have to triangulate programmatically.
Is it discouraged to use shapes extending javafx.scene.shape.Shape within 3D space? How're they drawn internally?
If the question is "should I use 2D Shape objects in 3D space?" in JavaFX then the answer is No because you will get all terrible performance that you are seeing. However it sounds like you are trying to make up for JavaFX's lack of a 3D PolyLine object using 2D objects and rotating them in 3D space. If that is true, instead use the free open-source F(X)yz library:
http://birdasaur.github.io/FXyz/
For example the PolyLine3D class which allows you to simply specify a list of Point3Ds and it will connect them for you:
/src/org/fxyz/shapes/composites/PolyLine3D.java
and you can see example code on how to use it in the test directory:
/src/org/fxyz/tests/PolyLine3DTest.java
I draw few rectangles inside the QGraphicsView ; I use custom stipple pattern for these by creating a QBrush with my QPixmap. This gets displayed with the default zoom level as expected.
When I call view->scale(), the rectangles show up bigger or smaller as I expected. However Qt has scaled the individual bits of the stipple pattern which is not expected; I expected it to draw the larger or smaller rectangle again with the brush.
Eg.
If I had used a stipple pattern with one pixel dot and pixel space, after zooming in, I want to see a larger rectangle but I want the same stipple pattern with same pixel gaps. Is this achievable somehow? Thanks.
I ran into the same problem while developing an EDA tool companion in Qt.
After some trying, what I did (and seems to work for me) is to create a custom graphics item. On the paint method, I do:
QBrush newBrush = brush_with_pattern;
newBrush.setTransform(QTransform(painter->worldTransform().inverted()));
painter->setBrush(newBrush);
That is to apply the inverse transformation of the item to the brush (so it does not scale).
I think that the setDashOffset is only for the border of the shapes (not the fill).
You may use QPen::setDashOffset:
http://harmattan-dev.nokia.com/docs/library/html/qt4/qpen.html#setDashOffset
You'll need to set the offset based on the scenes zoom/scale level. You can grab a pointer to the scene in your item by calling scene(), don't forget to check for NULL though since it will be NULL when not added to the scene (although you shouldn't in theory get a paint() when not in a scene).
The other option is to use:
http://doc.qt.digia.com/qt/qpainter.html#scale
To undo the views scaling on your painter.
In case anyone is still looking on this, a related question here regarding scaling of standard fill patterns instead of pixmap fill patterns may help. Basically, it may not be possible to modify scaling of standard fill patterns (a few workaround ideas are listed), but, working with alpha values instead gives the desired effect if you are looking for varying colors, especially gray levels - and is much less convoluted.
Dear Friends,Can anyone tell me how to show one picture in GLCanvas and by using mouse how to rotate a picture in the GLCanvas.I m new to this jogl developement.Can u pls provide me how to do this.If possible provide me some code snippet and some reference site to get a clear idea about jogl developement.
regards,
s.kumaran.
To show an image on GLCanvas , create a polygon using gl.glBegin(GL.GL_POLYGON) and load the texture using the Class TextureIO .Then using the MouseListener in Java Swings ,you can easily control the rotation of the image(i.e,the textured polygon) by simply changing the position of Camera or doing some transformations( "gl.glRotate(angle,x-axis,y-axis,z-axis) in your case") in Model-View matrix .
The easiest way to do this will be to texture a Quad with the picture and then apply affine transforms to that Quad. Rendering this quad will let you see a rotating picture you can do pretty much any transform by shifting the vertices of the Quad.
I'm assuming that you are drawing a 3D scene and want to change it's orientation, rather than having a 2D image which you wish to rotate.
The short answer is that it takes place in two parts. You need to store an orientation of your scene as a 4x4 matrix (homogeneous matrix - search for it if you don't know what that is). You first need to write code that translates a mouse drag into a change of that 4x4 matrix. So when the mouse is dragged up apply an appropriate rotation or whatever to the matrix.
Then you need to redraw the scene, but using the new transformed 4x4 matrix. Use glMatrixMode to specify which matrix (use either GL_PROJECTION or GL_MODELVIEW) and then functions like glMultMatrixf() to manipulate the appropriate matrix.
If that didn't make sense pick up an OpenGL tutorial on how to rotate scenes. OpenGL and JOGL are close enough that methods from OpenGL work in JOGL.