[News][Staff] solidFRAME - a 3D engine for the TI-83+(SE)

[tr1p1ea]

Hi guys,

Just thought id let you know that i have uploaded a project to
ticalc.org today. It is a 3D engine for the TI-83+ series calculators.

The program is a 3D model viewer that enables the user to view and
interact with a 3D model in real-time. Note that it renders
flat pattern-shaded polygons. Also included is a utility to convert
Wavefront OBJ models to .8xp programs for use with this
viewer.

It is written in z80 assembly and a 15MHz calculator is recommended.

It is in beta testing so there could be problems. Please report any bugs
if you find any.

Here is a link: http://www.ticalc.org/archives/files/fi ... 45097.html

Also here are some screenies.




Id appreciate feedback if anyone has some.

Enjoy.

[benryves]

Very impressive work - I lack the relevant equipment to install it on a calculator so I played around in an emulator and it seems to work very well indeed.

Do you have any plans for what you'll work on adding next?

[tr1p1ea]

Hi Ben, Thanks for the quick reply! .

I need to correct the back-face culling for a start and add polygon clipping i think. Plus i need reorganise the memory structure a little.

For now i might just have a go at making some 3D models to test with .

[benryves]

I see - how have you implemented the backface culling at the moment?

[tr1p1ea]

The BFC is very basic, at present i do it after transforming but before projecting using:

; bfc = (x0-x1)*(y2-y1)-(y0-y1)*(x2-x1)

Where the sign is taken to determine which direction the polygon is facing. The error involved means that faces on the boundary between facing and not-facing are sometimes confused.

Ill need to implement it properly in the future.

[benryves]

I gather it's the "before projecting" that is causing the error? Ah well, I look forwards to seeing where you take this next.

[NanoWar]

Hmm why is the X-Wing model not included? !!! Awesome work.

[tr1p1ea]

Ill tidy up the xwing model and release if you like.

In the meantime i have been experimenting with basic lighting effects:


Here is a better screenshot of whats going on (i hope):


Also here is the xwing:

[JamesV]

As usual, Pat, you never cease to amaze! This looks just amazing!

[merthsoft]

The slower-spinning cube does indeed make it more clear what you're doing--and it looks great! Does that work with multiple objects? Does it perform well?

Also, that X-Wing looks great

[tr1p1ea]

I do need to fully implement it so that it is based on an idependant world position as opposed to the camera (was a quick hax), but it supports all objects in the 'world' without any code changes.

[merthsoft]

That's pretty impressive. What about multiple light-sources?

[tr1p1ea]

Well technically it would be possible, but i would have to properly implement lighting as opposed to this hack. That being said, per model lights should be easy too.

Also i have added polygon clipping, but only in 2D which means that any polygons that have a vertex behind the near plane (z=0) will be culled and not clipped as demonstrated in this screenie:



Still that only typically happens when you are 'in the middle' of a model so in most cases it should be acceptable.

[yhean]

Very, very nice work! I really like the lighting effects.
Good to see someone is still working on a 3D engine

[tr1p1ea]

Oh wow hi yhean!! Long time no see, i hope you're doing well!

Thanks for your kind comments, i remember your 3D engine (juha3D?), it was very impressive and a large inspiration for my interest in calc 3D .

Good to see you .