multiple objects in t_jit_glchunk

Dec 19, 2007 at 2:01am

multiple objects in t_jit_glchunk

So this time I made sure I RTFM a couple of times before asking. It’s not
all in the last paragraph of the ob3d docs this time;-)

I’m creating a number of shapes in different sizes, extracted from a video
matrix. The process reallocates a new jit_glchunk every time because the
vertex count varies. All is good, I managed to populated the chunk and draw
it to the screen or output it as a gl matrix. I have one questions still.

What is the way to put multiple separate shapes in a chunk? Do I need to
generate a connections matrix to distinguish between them? Or maybe generate
a separate chunk for every shape and link them together using the next_chunk
pointer?

Cheers,
Thijs

#35056
Dec 19, 2007 at 2:14am

Hi Thijs,
How are you planning on integrating your object into the jitter opengl
environment? I’m asking because there might be better ways to handle
your output geometry than making chunks. On example that comes to
mind is to output 2 matrices. One would be a vertex matrix and the
other an index matrix. The vertex matrix can be some maximum size
because the index matrix would tell jit.gl.mesh what vertices to
actually draw, so there could be extra data on the end of the matrix
that isn’t actually used.

best,
wes

On Dec 18, 2007 6:01 PM, Thijs Koerselman

wrote:
> So this time I made sure I RTFM a couple of times before asking. It’s not
> all in the last paragraph of the ob3d docs this time;-)
>
> I’m creating a number of shapes in different sizes, extracted from a video
> matrix. The process reallocates a new jit_glchunk every time because the
> vertex count varies. All is good, I managed to populated the chunk and draw
> it to the screen or output it as a gl matrix. I have one questions still.
>
> What is the way to put multiple separate shapes in a chunk? Do I need to
> generate a connections matrix to distinguish between them? Or maybe generate
> a separate chunk for every shape and link them together using the next_chunk
> pointer?
>
> Cheers,
> Thijs
>
>
>

#119075
Dec 19, 2007 at 3:08am

Hi Wes, I’m not sure actually. The shapes might even be rendered back to a
video matrix:-) This external, for now, serves as an input for other people
to do some video animations. I figured because its not for my personal use,
I’d best stick to the jitter standards as much as possible.

I like your idea of separating the matrices. The index matrix will still be
dynamic, no? Or can I fill the remaining space with -1 or something, so
jit.gl.mesh ignores it?

When you create an index matrix for a glchunk isn’t it output as a separate
matrix anyway? I’m a bit unclear what the difference is between a glchunk
and the separate matrix approach. Does jit.gl.mesh take a glchunk as input
or do you have to split it first?

Cheers,
Thijs

On Dec 19, 2007 2:14 AM, Wesley Smith wrote:

> Hi Thijs,
> How are you planning on integrating your object into the jitter opengl
> environment? I’m asking because there might be better ways to handle
> your output geometry than making chunks. On example that comes to
> mind is to output 2 matrices. One would be a vertex matrix and the
> other an index matrix. The vertex matrix can be some maximum size
> because the index matrix would tell jit.gl.mesh what vertices to
> actually draw, so there could be extra data on the end of the matrix
> that isn’t actually used.
>
> best,
> wes
>
> On Dec 18, 2007 6:01 PM, Thijs Koerselman

> wrote:
> > So this time I made sure I RTFM a couple of times before asking. It’s
> not
> > all in the last paragraph of the ob3d docs this time;-)
> >
> > I’m creating a number of shapes in different sizes, extracted from a
> video
> > matrix. The process reallocates a new jit_glchunk every time because the
> > vertex count varies. All is good, I managed to populated the chunk and
> draw
> > it to the screen or output it as a gl matrix. I have one questions
> still.
> >
> > What is the way to put multiple separate shapes in a chunk? Do I need to
> > generate a connections matrix to distinguish between them? Or maybe
> generate
> > a separate chunk for every shape and link them together using the
> next_chunk
> > pointer?
> >
> > Cheers,
> > Thijs
> >
> >
> >
>

http://www.nano-soundworks.com

#119076

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