Graphics

28-Nov-09 21:40

WaveK89 wrote:
I am trying to draw actual poker cards.

If you want to use a ready made library there is some good information here[^].

3D Image Display.

ashwath197919-Nov-09 23:20

ashwath1979

19-Nov-09 23:20

Hi All,

The task which is given to me is that i have to show a cylinder in 3D.Then when i click on any part of the cylinder and drag the mouse i should be able to deform the cylinder and when i leave the mouse the object should be in the last deformed state.I am planning to use directx for this.

Any inputs from you will be very helpful for me.

Thanking you in Advance,

Regards,
Ashwath.

Re: 3D Image Display.

Baltoro21-Nov-09 11:48

Baltoro

21-Nov-09 11:48

...Ha Ha,...well, looks like I was wrong. Sorry.
Did you give any thought to the problem?
This would be a good place to start:
DirectD3D Tutorials, MSDN[^], or, maybe, D3D Reference, MSDN[^]
There is also a standard Direct D3D API: D3DXCreateCylinder[^]

Re: 3D Image Display.

LunaticFringe22-Nov-09 7:32

Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

22-Nov-09 7:32

So how committed are you to using DirectX? I could help if you were implementing this in OpenGL, but not DX.

Re: 3D Image Display.

Tim Craig22-Nov-09 8:06

Tim Craig

22-Nov-09 8:06

You measure democracy by the freedom it gives its dissidents, not the freedom it gives its assimilated conformists.

RobstaHendricks12-Nov-09 2:55

RobstaHendricks

12-Nov-09 2:55

Ok, so I have been trawling the web to try and find an answer to this, but to no avail.

Basically, I have a DirectShow filter (well 2) which will allow me to configure a Hauppage WinTV USB adapter (though I doubt the specific filter is 100% relevant to answer the question) to use PAL (I) and to set the source as Composite In. So far, I have found ways to display a filter's property page, and to change the settings of a DMO filter, but not enumerate and change the properties of a non DMO source filter.

The reason for needing to do this is that both filter options seem to reset with Windows, meaning that our source becomes NTSC and Tuner In, rather than Pal-I and Composite In. The filters are classed as a Video Capture Source (WinTV HVR-900H Capture) and a WDM Streaming Crossbar Device (WinTV HVR-900H Crossbar), but the ability to change any property of any filter sans a GUI will be a step in the right direction

I am using a .Net wrapper to play with the filter graph through c#, but have limited knowledge of COM interop (thus the wrapper). Any answers in C++ are fine and dandy also, then I'll worry about how to convert them to C#, just in need of an example really.

What's the easiest method to go about this?

Re: Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

Richard MacCutchan12-Nov-09 5:55

Re: Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

12-Nov-09 5:55

Please don't spam the forums - ask your question once only in the appropriate forum.

RobstaHendricks12-Nov-09 23:03

RobstaHendricks

12-Nov-09 23:03

Sorry, I thought as it was, in fact, relevant to the places I put it, that was acceptable. Was more through my frustration of trawling the web to no avail. Suprised no one else has asked this question before?

Re: Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

Richard MacCutchan12-Nov-09 23:18

Re: Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

12-Nov-09 23:18

RobstaHendricks wrote:
I thought as it was, in fact, relevant to the places I put it, that was acceptable.

No, it just means people get somewhat annoyed at reading the same question multiple times. Check this[^] out for the gudelines on how to use the forums correctly.

RobstaHendricks13-Nov-09 0:09

RobstaHendricks

13-Nov-09 0:09

Yep, read that and it said only not to put a link to your post in an inappropriate forum:

"9.Please do not post links to your question in one forum from another, unrelated forum (such as the lounge)."

I understand what you are saying though, but didn't know which of the forums to post in. I'll take note for next time.

Any how, did you know which filter graph builder I should use to import the settings from the GRF file? I expect I'll figure which method to use from there.

Re: Set the properties of a DirectShow filter (not DMO filter) in code (no GUI)

Richard MacCutchan13-Nov-09 0:29

color picking method to select primitive in opengl

13-Nov-09 0:29

Sorry, I don't know the answer to your query, just hope someone else with the relevant knowledge sees the post.

gourishsio12-Nov-09 1:53

Re: color picking method to select primitive in opengl

12-Nov-09 1:53

Hello,

I am using color picking method to select a primitive in my application.. At present it is picking only single object.. I just wanted to clarify few doubts..

It is working fine when i click on a single object.. I mean if there are two objects lying on the same pixel.. And if i click that pixel, then i get only one object.. How can i get both the objects, using this method..?? Is it possible..??

Thanks in advance

LunaticFringe22-Nov-09 7:52

Re: color picking method to select primitive in opengl

22-Nov-09 7:52

If you use the standard picking mechanism instead of color picking, you will get hit records for all objects within the selection volume, not just the first object in the Z-order. The standard mechanism is more cumbersome, but the trade-off is that it can be faster.

gourishsio22-Nov-09 17:15

Re: color picking method to select primitive in opengl

22-Nov-09 17:15

But I'm using VBOs.. And SELECT render mode doesnt work there i guess..?? Am i right..??

LunaticFringe23-Nov-09 10:12

glDrawElements() draws only part of my mesh... :-x

23-Nov-09 10:12

gourishsio wrote:
And SELECT render mode doesnt work there i guess..?? Am i right..??

I haven't tried it, but I don't see why not. The location of the vertex data isn't really relevant. Once you've created your VBO, you still render it with glDrawArrays (or an equivalent sequence). What may complicate the issue is the fact that you'll have to break up the rendering of the object into a number of steps. Each sub-block that you want to uniquely identify in the hit test will need it's own 'name', and that name will have to be passed to glLoadName before the relevant piece of geometry is rendered. But AFAIK it should work with data stored in a VBO.

gourishsio12-Nov-09 1:52

Re: glDrawElements() draws only part of my mesh... :-x

12-Nov-09 1:52

Hello..

I have recently shifted from Display lists to VBOs... It's a very nice thing in OpenGL i found to render huge amount of data smoothly..

Let me explain you the scenario.. I have maintained a list of triangle objects as

std::map<unsigned int, EObjects*> MeshElements

Thus, MeshElements contains all the triangles generated by the mesh generator. Now in order to display, i call a routine first as shown below:

mVertexCount = MeshElements.size();

mVertices = new GLfloat[mVertexCount * 6];
mIndices = new GLuint[mVertexCount * 3];

int v_ind = 0, i_ind = 0;

for( std::map<unsigned int, EObjects*>::iterator it = MeshElements.begin(); it != MeshElements.end(); it++ )
{
     EObjects *ob = (*it).second;
     mVertices[v_ind] = ob->GetNodeOne().GetX(); v_ind++;
     mVertices[v_ind] = ob->GetNodeOne().GetY(); v_ind++;
     mIndices[i_ind] = ob->GetNodeOneIndex(); i_ind++;
     mVertices[v_ind] = ob->GetNodeTwo().GetX(); v_ind++;
     mVertices[v_ind] = ob->GetNodeTwo().GetY(); v_ind++;
     mIndices[i_ind] = ob->GetNodeTwoIndex(); i_ind++;
     mVertices[v_ind] = ob->GetNodeThree().GetX(); v_ind++;
     mVertices[v_ind] = ob->GetNodeThree().GetY(); v_ind++;
     mIndices[i_ind] = ob->GetNodeThreeIndex(); i_ind++;
}

glGenGuffersARB(BufferSize, BufferName);

where BufferSize and BufferName are declared globally as follows:

enum{
  INDEX_OBJECT = 0,
  POSITION_OBJECT = 1
};

static const int BufferSize = 2;
static GLuint BufferName[BufferSize];

Below is my rendering code:

glBindBufferARB( GL_ARRAY_BUFFER_ARB, BufferName[POSITION_OBJECT]);
glBufferDataARB( GL_ARRAY_BUFFER_ARB, mVertexCount * 6 * sizeof(float), mVertices, GL_STREAM_DRAW_ARB );
glVertexPointer(2, GL_FLOAT, 0, 0);

glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, BufferName[INDEX_OBJECT] );
glBufferDataARB( GL_ELEMENT_ARRAY_BUFFER_ARB, mVertexCount * 3 * sizeof(GLuint), mIndices, GL_STREAM_DRAW_ARB );

glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_INDEX_ARRAY);

glDrawElements( GL_TRIANGLES, mVertexCount*3, GL_UNSIGNED_INT, NULL );

glDisableClientState(GL_INDEX_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);

This code is working fine.. But, only the outer part of the mesh is displayed.. the Inner part is not displayed.. I mean to say, if the mesh is of shape "D", it should have filled all the triangles in "D".. Instead of doing so, it is rather, drawing triangles only along the border of the shape "D" Inner part, triangles are not drawn..

Before using glDrawElements(), i was using glDrawArrays().. It also produced the same output.. So I used, GL_POINTS with glDrawArrays(), just to check if it is reading all the points.. In response to this test, it rendered all the points.. But when i said, GL_TRIANGLES, it is not rendering the inner part..

On the other hand, GL_POINTS with glDrawElements() is also rendering only at the boundaries.. Not inner part like glDrawArrays()..

Is something wrong with my code above..?? Please someone guide me properly..

Thanks in advance..

LunaticFringe20-Nov-09 5:36

Re: glDrawElements() draws only part of my mesh... :-x

20-Nov-09 5:36

At a guess, I'd say it sounds as if you have issues with vertex winding direction and normal vector polarity. If you haven't already, try enabling double-sided rendering and lighting of the triangles and see if they show up. I suspect that the invisible triangles aren't being rendered because you're looking at their backsides, as defined by the normal and the order in which the vertices are fed to the GL engine.

Just a guess.

gourishsio23-Nov-09 18:47

Re: glDrawElements() draws only part of my mesh... :-x

23-Nov-09 18:47

how do i do that double sided rendering..?? Sorry i'm new but, i guess, by any chance are you speaking about glEnable(CULL_FACE)...??

LunaticFringe23-Nov-09 19:18

OpenGL Lib for SmartPhone application

23-Nov-09 19:18

Disable back-face culling - glDisable(GL_CULL_FACE); specify double -sided material properties - e.g., glMaterialfv(GL_FRONT_AND_BACK...); enable double-sided lighting - glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, TRUE).

King Tran11-Nov-09 18:05

King Tran

11-Nov-09 18:05

i want to draw 2D graphic using OpenGL in smartphone or PDA with windows mobile system. but where Smile | :)

can i download the opengl libs suport the embed system application?

thanks.

Re: OpenGL Lib for SmartPhone application

LunaticFringe20-Nov-09 5:31