How to load a 3d object in Android? - android

I have the .obj file and .mtl file but don't know how to import it. I have tried the tutorials, they aren't working.

One way to load an Object from an .obj file is to first get the inputstream from the file, then you go through each line, since one line consists of one vertex. The part where you then use youre data from the .obj file to acctually draw it is something that you easily can find a bunch of tutorials on online, one example: http://www.droidnova.com/android-3d-game-tutorial-part-i,312.html . If you want to get deeper into Opengl and acctually learn alot you can use Nehe the allmightys online tutorial that covers very much and goes quite deep into OpenGL programming: http://nehe.gamedev.net/ .
Anyway, the .obj file loading could start of by something like this:
while ((line = reader.readLine()) != null)
{
if (line.startsWith("f"))
{
faces++;
processFLine(line);
} else if (line.startsWith("vn"))
{
normals++;
processVNLine(line);
} else if (line.startsWith("vt"))
{
UVCoords++;
processVTLine(line);
} else if (line.startsWith("v"))
{
vertices++;
processVLine(line);
}
}
For everything except when line starts with 'f' it's quite straight forward, you just store thoose two or three values in something, I preferred a Vector:
private void processVNLine(String line)
{
String[] tokens = line.split("[ ]+");
int c = tokens.length;
for (int i = 1; i < c; i++)
{ // add the normals to the normal vector
_vn.add(Float.valueOf(tokens[i]));
}
}
For the faces part (where line starts with 'f', you would preferably first check how many '/' each vertex consists of:
private void processFLine(String line)
{
String[] tokens = line.split("[ ]+");
int c = tokens.length;
if (tokens[1].matches("[0-9]+"))
{
caseFEqOne(tokens, c);
}
if (tokens[1].matches("[0-9]+/[0-9]+"))
{
caseFEqTwo(tokens, c);
}
if (tokens[1].matches("[0-9]+//[0-9]+"))
{
caseFEqOneAndThree(tokens, c);
}
if (tokens[1].matches("[0-9]+/[0-9]+/[0-9]+"))
{
caseFEqThree(tokens, c);
}
}
Each face is built up by three vertex, where each vertex indexes is v/vt/vn.
This is what could happen if you have v/vt. It stores the indices in seperate vectors.
private void caseFEqTwo(String[] tokens, int c)
{
for (int i = 1; i < c; i++)
{
Short s = Short.valueOf(tokens[i].split("/")[0]);
s--;
_vPointer.add(s);
s = Short.valueOf(tokens[i].split("/")[1]);
s--;
_vtPointer.add(s);
}
}
Now you have handled this by adding the indices into sperarate Vectors or arrays.
Now you should have Vectors that consists of coordinates and vector that consists of indices for each type(v, vt or vn). You should as well have the number of faces.
By knowing the number of faces you can now start a loop that goes from 0 to number of faces.
If you now create new vectors that consists of the final result, you can in this loop move the coordinates at the index from the loop index to the loop index in the results vectors.
This may need some explenation maybe so here is a simple example:
private void reArrange()
{
Iterator<Short> i;
short s;
i = _vPointer.iterator();
while (i.hasNext())
{
s = (short) (i.next() * 3);
for (int k = 0; k < 3; k++)
{
_vResult.add(_v.get(s + k));
}
}
i = _vnPointer.iterator();
while (i.hasNext())
{
s = (short) (i.next() * 3);
for (int k = 0; k < 3; k++)
{
_vnResult.add(_vn.get(s + k));
}
}
i = _vtPointer.iterator();
while (i.hasNext())
{
s = (short) (i.next() * 2);
for (int k = 0; k < 2; k++)
{
_vtResult.add(1f - _vt.get(s + k));
}
}
_indices = new short[faces * 3];
for (short k = 0; k < faces * 3; k++)
{
_indices[k] = k;
}
}
Now your'e acctually done and have the information you need from the .obj file. So by converting thoose vectors to FloatBuffers and by creating a ShortBuffer that is as simple as 0,1,2,3,4,5 ... and so on you can use thoose with OpenGL-ES to draw your'e object.
(This is not completly written by me, I used a basic concept i found somewhere online, can't find now tho, and then made it fit nicely to what i wanted and adjusted it abit to get easier to understand)
What this doesn't cover is the part where you also load a .mtl file that you oftenly will get as well while exporting an Object from a program. If you want to implement that as well you could have a look at this: http://people.sc.fsu.edu/~jburkardt/data/mtl/mtl.html
This is something that can be good to have if your'e building an Object in a program and want a more exact replica where this will give you values for how light should be handled to materials as well.
If you have any questions, feel free to ask them.
(I know that this might not be the optimal way of loading a .obj file since we use up to 9 different vectors but if you use serialization as well this might acctually get quite fast.)

OpenGL is not a scene graph library. It provides you a set of sophisticated drawing tools, but nothing more. Loading 3D models, scene management, etc. are all left for you to implement, or use a library for.

it's far late now ...but still helpful solution :
min3D engine help to load 3d model in android
Following are syeps:
1) Download Rajawali lib.
2) Create an RenderActivity
private Object3dContainer faceObject3D;
private Object3dContainer objModel;
#Override
public void initScene() {
scene.lights().add(new Light());
scene.lights().add(new Light());
Light myLight = new Light();
myLight.position.setZ(150);
scene.lights().add(myLight);
IParser parser = Parser.createParser(Parser.Type.OBJ,
getResources(), "com.azoi.opengltutor:raw/monster_high", true);
parser.parse();
objModel = parser.getParsedObject();
objModel.scale().x = objModel.scale().y = objModel.scale().z = .7f;
scene.addChild(objModel);
}
add ur 3d model obj file in res/raw directory...here it's monster_high
That's it...register activity in Manifest and run :) .
if you want to move 3d model override updateScene(..):
public void updateScene() {
super.updateScene();
objModel.rotation().x++;
objModel.rotation().y--;
objModel.rotation().z++;
}
more on here http://code.google.com/p/min3d/wiki/HowToLoadObjFile Enjoy :)

Related

Android Studio - App crash when using intent parameter

I have a function that 'crafts' products using two String parameters.
This is working fine when I put in hard coded strings like 'Wheel' & 'Car'.
But it makes my application crash if I try to put in the exact same strings but then provided by an intent.
I already tried to give in variable into the intent instead of a hard coded string. That did not work either.
Here is some part of the code. EDIT: Error log now included
productLeft = getIntent().getStringExtra("PRODUCT LEFT");
productRight = getIntent().getStringExtra("PRODUCT RIGHT");
public void craft(String product1, String product2) {
String[][] Products = factory.getProductList();
int i = 0;
while (finalProduct == "") {
int j;
for(j = 0; j < 3; j++){
if (product1 == Products[i][0] || product2 == Products[i][0]) {
if (product1 == Products[i][1] || product2 == Products[i][1]){
finalProduct = Products[i][2];
}
}
i++;
}
}
}
Problem is with the array index obviously. The array has only four elements and you are fetching index 4, probably in for loop with i variable. But then again I also do not see the role of j in that loop, can't tell without other parts of code.

Get video resolution In ExoPlayer

How to get video resolution from video Url according to net speed like in you tube
it automatically gets 128 p,360 p using Exo player.
The core points you'll want to look into are around track selection (via the TrackSelector) as well as the TrackSelectionHelper. I'll include the important code samples below which will hopefully be enough to get you going. But ultimately just following something similar in the demo app will get you where you need to be.
You'll hold onto the track selector you init the player with and use that for just about everything.
Below is just a block of code to ideally cover the gist of what you're trying to do since the demo does appear to over-complicate things a hair. Also I haven't run the code, but it's close enough.
// These two could be fields OR passed around
int videoRendererIndex;
TrackGroupArray trackGroups;
// This is the body of the logic for see if there are even video tracks
// It also does some field setting
MappedTrackInfo mappedTrackInfo = trackSelector.getCurrentMappedTrackInfo();
for (int i = 0; i < mappedTrackInfo.length; i++) {
TrackGroupArray trackGroups = mappedTrackInfo.getTrackGroups(i);
if (trackGroups.length != 0) {
switch (player.getRendererType(i)) {
case C.TRACK_TYPE_VIDEO:
videoRendererIndex = i;
return true;
}
}
}
// This next part is actually about getting the list. It doesn't include
// some additional logic they put in for adaptive tracks (DASH/HLS/SS),
// but you can look at the sample for that (TrackSelectionHelper#buildView())
// Below you'd be building up items in a list. This just does
// views directly, but you could just have a list of track names (with indexes)
for (int groupIndex = 0; groupIndex < trackGroups.length; groupIndex++) {
TrackGroup group = trackGroups.get(groupIndex);
for (int trackIndex = 0; trackIndex < group.length; trackIndex++) {
if (trackIndex == 0) {
// Beginning of a new set, the demo app adds a divider
}
CheckedTextView trackView = ...; // The TextView to show in the list
// The below points to a util which extracts the quality from the TrackGroup
trackView.setText(DemoUtil.buildTrackName(group.getFormat(trackIndex)));
}
// Assuming you tagged the view with the groupIndex and trackIndex, you
// can build your override with that info.
Pair<Integer, Integer> tag = (Pair<Integer, Integer>) view.getTag();
int groupIndex = tag.first;
int trackIndex = tag.second;
// This is the override you'd use for something that isn't adaptive.
override = new SelectionOverride(FIXED_FACTORY, groupIndex, trackIndex);
// Otherwise they call their helper for adaptives, which roughly does:
int[] tracks = getTracksAdding(override, trackIndex);
TrackSelection.Factory factory = tracks.length == 1 ? FIXED_FACTORY : adaptiveTrackSelectionFactory;
override = new SelectionOverride(factory, groupIndex, tracks);
// Then we actually set our override on the selector to switch the quality/track
selector.setSelectionOverride(rendererIndex, trackGroups, override);

Implementing a multiple input filter graph with the Libavfilter library in Android NDK

I am trying to use the overlay filter with multiple input sources, for an Android app. Basically, I want to overlay multiple video sources on top of a static image.
I have looked at the sample that comes with ffmpeg and implemented my code based on that, but things don't seem to be working as expected.
In the ffmpeg filtering sample there seems to be a single video input. I have to handle multiple video inputs and I am not sure that my solution is the correct one. I have tried to find other examples, but looks like this is the only one.
Here is my code:
AVFilterContext **inputContexts;
AVFilterContext *outputContext;
AVFilterGraph *graph;
int initFilters(AVFrame *bgFrame, int inputCount, AVCodecContext **codecContexts, char *filters)
{
int i;
int returnCode;
char args[512];
char name[9];
AVFilterInOut **graphInputs = NULL;
AVFilterInOut *graphOutput = NULL;
AVFilter *bufferSrc = avfilter_get_by_name("buffer");
AVFilter *bufferSink = avfilter_get_by_name("buffersink");
graph = avfilter_graph_alloc();
if(graph == NULL)
return -1;
//allocate inputs
graphInputs = av_calloc(inputCount + 1, sizeof(AVFilterInOut *));
for(i = 0; i <= inputCount; i++)
{
graphInputs[i] = avfilter_inout_alloc();
if(graphInputs[i] == NULL)
return -1;
}
//allocate input contexts
inputContexts = av_calloc(inputCount + 1, sizeof(AVFilterContext *));
//first is the background
snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=1/1:pixel_aspect=0", bgFrame->width, bgFrame->height, bgFrame->format);
returnCode = avfilter_graph_create_filter(&inputContexts[0], bufferSrc, "background", args, NULL, graph);
if(returnCode < 0)
return returnCode;
graphInputs[0]->filter_ctx = inputContexts[0];
graphInputs[0]->name = av_strdup("background");
graphInputs[0]->next = graphInputs[1];
//allocate the rest
for(i = 1; i <= inputCount; i++)
{
AVCodecContext *codecCtx = codecContexts[i - 1];
snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
codecCtx->width, codecCtx->height, codecCtx->pix_fmt,
codecCtx->time_base.num, codecCtx->time_base.den,
codecCtx->sample_aspect_ratio.num, codecCtx->sample_aspect_ratio.den);
snprintf(name, sizeof(name), "video_%d", i);
returnCode = avfilter_graph_create_filter(&inputContexts[i], bufferSrc, name, args, NULL, graph);
if(returnCode < 0)
return returnCode;
graphInputs[i]->filter_ctx = inputContexts[i];
graphInputs[i]->name = av_strdup(name);
graphInputs[i]->pad_idx = 0;
if(i < inputCount)
{
graphInputs[i]->next = graphInputs[i + 1];
}
else
{
graphInputs[i]->next = NULL;
}
}
//allocate outputs
graphOutput = avfilter_inout_alloc();
returnCode = avfilter_graph_create_filter(&outputContext, bufferSink, "out", NULL, NULL, graph);
if(returnCode < 0)
return returnCode;
graphOutput->filter_ctx = outputContext;
graphOutput->name = av_strdup("out");
graphOutput->next = NULL;
graphOutput->pad_idx = 0;
returnCode = avfilter_graph_parse_ptr(graph, filters, graphInputs, &graphOutput, NULL);
if(returnCode < 0)
return returnCode;
returnCode = avfilter_graph_config(graph, NULL);
return returnCode;
return 0;
}
The filters argument of the function is passed on to avfilter_graph_parse_ptr and it can looks like this: [background] scale=512x512 [base]; [video_1] scale=256x256 [tmp_1]; [base][tmp_1] overlay=0:0 [out]
The call breaks after the call to avfilter_graph_config with the warning:
Output pad "default" with type video of the filter instance "background" of buffer not connected to any destination and the error Invalid argument.
What is it that I am not doing correctly?
EDIT: The are two issues that I have discovered:
Looks like the description of avfilter_graph_parse_ptr is a bit vague. The ouputs parameter represents a list of the current outputs of the graph, in my case that being the graphInputs variable, because these are the outputs from the buffer filter. The inputs parameter represents a list of the current inputs of the graph, in this case this is the graphOutput variable, because it represents the input to the buffersink filter.
I did some testing with a scale filter and a single input. It seems that the name of the AVFilterInOut structure required by avfilter_graph_parse_ptr needs to be in. I have tried with different versions: in_1, in_link_1. None of them work and I have not been able to find any documentation related to this.
So the issue still remains. How do I implement a filter graph with multiple inputs?
I have found a simple solution to the problem.
This involves replacing the avfilter_graph_parse_ptr with avfilter_graph_parse2 and adding the buffer and buffersink filters to the filters parameter of avfilter_graph_parse2.
So, in the simple case where you have one background image and one input video the value of the filters parameter should look like this:
buffer=video_size=1024x768:pix_fmt=2:time_base=1/25:pixel_aspect=3937/3937 [in_1]; buffer=video_size=1920x1080:pix_fmt=0:time_base=1/180000:pixel_aspect=0/1 [in_2]; [in_1] [in_2] overlay=0:0 [result]; [result] buffersink
The avfilter_graph_parse2 will make all the graph connections and initialize all the filters. The filter contexts for the input buffers and for the output buffer can be retrieved from the graph itself at the end. These are used to add/get frames from the filter graph.
A simplified version of the code looks like this:
AVFilterContext **inputContexts;
AVFilterContext *outputContext;
AVFilterGraph *graph;
int initFilters(AVFrame *bgFrame, int inputCount, AVCodecContext **codecContexts)
{
int i;
int returnCode;
char filters[1024];
AVFilterInOut *gis = NULL;
AVFilterInOut *gos = NULL;
graph = avfilter_graph_alloc();
if(graph == NULL)
{
printf("Cannot allocate filter graph.");
return -1;
}
//build the filters string here
// ...
returnCode = avfilter_graph_parse2(graph, filters, &gis, &gos);
if(returnCode < 0)
{
cs_printAVError("Cannot parse graph.", returnCode);
return returnCode;
}
returnCode = avfilter_graph_config(graph, NULL);
if(returnCode < 0)
{
cs_printAVError("Cannot configure graph.", returnCode);
return returnCode;
}
//get the filter contexts from the graph here
return 0;
}
I cant add a comment so i would just like to add you can fix "Output pad "default" with type video of the filter instance "background" of buffer not connected to any destination" by not having a sink at all. The filter will automatically make the sink for you. So you are adding too many pads
For my case I had a transformation like this:
[0:v]pad=1008:734:144:0:black[pad];[pad][1:v]overlay=0:576[out]
If you try ffmpeg from command line, it will work:
ffmpeg -i first.mp4 -i second.mp4 -filter_complex "[0:v]pad=1008:734:144:0:black[pad];[pad][1:v]overlay=0:576[out]" -map "[out]" -map 0:a output.mp4
Basically, increasing the overall size of first video, then overlapping the second one. After a long try, same problems as this thread, I got it working. The video filtering example from FFMPEG documentation (https://ffmpeg.org/doxygen/2.1/doc_2examples_2filtering_video_8c-example.html) works fine, and after digging into it, this went fine:
filterGraph = avfilter_graph_alloc();
NULLC(filterGraph);
bufferSink = avfilter_get_by_name("buffersink");
NULLC(bufferSink);
filterInput = avfilter_inout_alloc();
AVBufferSinkParams* buffersinkParams = av_buffersink_params_alloc();
buffersinkParams->pixel_fmts = pixelFormats;
FFMPEGHRC(avfilter_graph_create_filter(&bufferSinkContext, bufferSink, "out", NULL, buffersinkParams, filterGraph));
av_free(buffersinkParams);
filterInput->name = av_strdup("out");
filterInput->filter_ctx = bufferSinkContext;
filterInput->pad_idx = 0;
filterInput->next = NULL;
filterOutputs = new AVFilterInOut*[inputFiles.size()];
ZeroMemory(filterOutputs, sizeof(AVFilterInOut*) * inputFiles.size());
bufferSourceContext = new AVFilterContext*[inputFiles.size()];
ZeroMemory(bufferSourceContext, sizeof(AVFilterContext*) * inputFiles.size());
for (i = inputFiles.size() - 1; i >= 0 ; i--)
{
snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
videoCodecContext[i]->width, videoCodecContext[i]->height, videoCodecContext[i]->pix_fmt, videoCodecContext[i]->time_base.num, videoCodecContext[i]->time_base.den, videoCodecContext[i]->sample_aspect_ratio.num, videoCodecContext[i]->sample_aspect_ratio.den);
filterOutputs[i] = avfilter_inout_alloc();
NULLC(filterOutputs[i]);
bufferSource = avfilter_get_by_name("buffer");
NULLC(bufferSource);
sprintf(args2, outputTemplate, i);
FFMPEGHRC(avfilter_graph_create_filter(&bufferSourceContext[i], bufferSource, "in", args, NULL, filterGraph));
filterOutputs[i]->name = av_strdup(args2);
filterOutputs[i]->filter_ctx = bufferSourceContext[i];
filterOutputs[i]->pad_idx = 0;
filterOutputs[i]->next = i < inputFiles.size() - 1 ? filterOutputs[i + 1] : NULL;
}
FFMPEGHRC(avfilter_graph_parse_ptr(filterGraph, description, &filterInput, filterOutputs, NULL));
FFMPEGHRC(avfilter_graph_config(filterGraph, NULL));
The type of variables are the same as in example above, the args and args2 are char[512], where outputTemplate is "%d:v", basically the input video IDs from filtering expression. Couple of things to watch-out:
The video information in args, needs to be correct, time_base and sample_aspect_ration are copied from the video stream of format context.
Indeed the input, is what is for us output, and the other way around
The name of the filter is "in" for all our input filters(filterOutputs)

Android: Fill array up to a certain length

The situation
I have got different char[] arrays with a different amount of items. To avoid the "OutOfBounds"-Error while processing them I want to standardize them.
For Example:
My Array has following items: "5;9" --> What I want it to look like: "0,0,0,0,5,9" (fill up with "0"s to 6 items)
What I tried:
char[] myarray1 = mystring1.toCharArray();
...
for(int i=0; i<6; i++){
myarray1[i] = 0;
if(i<myarray1.length-1){
myarray1[i] = myarray1[i];
}else{
myarray1[i] = 0;
};
};
My code failed, because it evokes exactly that error...
I hope somebody can help me :)
Thanks!
The reason why your solution doesn't work is that you are using the same array for everything.
After char[] myarray1 = mystring1.toCharArray(); the length of myarray1 is 2, so you cannot simply assign entry 2,3,4 and 5 in your loop. Furthermore if you want the character ´0´ to be in the string, you need to surround your zeros with apostrophes.
You can fix your solution like this:
char[] myNewArray = new char[6];
int myarrayIndex = 0;
for(int i=0; i<6; i++)
{
if(i < (myNewArray.length - myarray1.length)) {
myNewArray[i] = '0';
} else {
myNewArray[i] = myarray1[myarrayIndex++];
};
};
System.out.println(myNewArray); //Will print out: 000059
An easier solution could be this:
myarray1 = String.format("%6s", mystring1).replace(' ', '0').toCharArray();
Firstly trying to fill 0's is not going to fix the error.
Secondly your logic is not right(assuming size as 6), change it to myString.length().
And I don't understand the point of myarray1[i] = myarray1[i];.
Anyways, every array with integer size is initialized by Zero's according to Java specs. On the other hand if you want to fill it with any other value, try Arrays.fill().
I think this function will accomplish what you're trying to do.
private static String formatString(String input)
{
String FORMATTED_STRING = "0,0,0,0,0,0";
int difference = FORMATTED_STRING.length() - input.length();
return FORMATTED_STRING.substring(0, difference) + input;
}

array copy by value fails (with clone() or arraycopy()) (Android, Java)

In order to make a copy of an array that holds a copy of the values instead of by reference I do the following:
int[][][] copy = {{{0}},{{0}},{{0,0}},{{0,0,0,0,0,0,0,0,0,0},{0,0,0,0,0,0,0,0,0,0}},{{0}},{{0,0}}};
System.arraycopy(spelerSpel, 0, copy, 0, spelerSpel.length);
then change a value IN THE COPY:
copy[SPELER_NUMMER][0][0] = baanSpelerNummer;
which results at that moment in the ORIGINAL (spelerSpel) array holding the same changed value, e.g.:
{{{4}},{{0}},{{0,0}},{{0,0,0,0,0,0,0,0,0,0},{0,0,0,0,0,0,0,0,0,0}},{{0}},{{0,0}}};
as the copy. I also tried .clone(), same result. What am I doing wrong?
By the way I target Android API 8, which doe not support Arrays.copyOf().
System.arraycopy() does not support deep copies, but it does pretty well in terms of performance for simple arrays.
You can use it with some additional loops to create your own multi-dimensional arraycopy3d():
public int[][][] arraycopy3d(int[][][] array) {
int[][][] copy = new int[array.length][][];
for (int i = 0; i < array.length; i++) {
copy[i] = new int[array[i].length][];
for (int j = 0; j < array[i].length; j++) {
copy[i][j] = new int[array[i][j].length];
System.arraycopy(array[i][j], 0, copy[i][j], 0, array[i][j].length);
}
}
return copy;
}

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