3d Objects

[samsc]

please email me your model.
3d models are very very finicky.

[litemover]

I've created 2 models from 2 separate applications and they work fine for me. I used Modo 201 for the first one, and Maya for the second.

Didn't need to do anything special except name them correctly. I named them 000model1football.obj, and 001model8wierdsphere.obj.

I would post them but I can't upload them here as the file manager needs to accept objs.

It works fine though. Double check that you have put them in the app directory and named them with a 3 digit number then model then a number then your description.obj. I did it just like how it was explained to me and it works. It might be possible that your normals are facing the wrong direction and you are seeing the back of your model. Try either rotating your model or camera if you are using a model that has only one side to it.

Make sure to frame up the model and export the model only not the entire scene. Also make sure not to export any materials with the model.

Christian Choi

[samsc]

i added the obj file type- but you should zip them- really.

one of the big advantages of obj files - is that they are text files - and they have a small number of features- so its not totally impossible to look at them a see incorrect things.

---

3d models are tough -

if you use maya and modo - - they do the right thing - most of the time.

i use maya, formz, cinema4d, concepts 3d -i tried modo. i can just make models work.
I have been able to get proper texture maps and uv coordinates out of cinema 4d - with non-mangled vertices -
I also sometimes have to resort to windows based 3d file translation programs.


but it sometimes takes lot of wrangling to make 3d - even transfering files from one 3d program to another, can be traumatic and difficult.

[litemover]

Here's a simple checklist of things to do to create models that will absolutely show up under any circumstances.

1. Use polys only, no Nurbs, Sub-ds, or anything else.
2. Only use quad faces, no n-gons or triangulated faces.
3. Make sure your object is oriented toward the Z camera
4. Make sure to follow richards instructions on how to name the models exactly.
5. Make sure to output only the selected model not the entire scene.
6. check you scale, if it is in mm, your model may be so small that it will look like a pinhole. If you have been working in very small units, just double check that you aren't making models that are too small.
7. try to use double sided geometry, i.e not planes. Instead of a plane use a very thin cube primitive, this way you are guaranteed not to have any reversed faces.
8. If you need to use planes, turn on your normals and make sure they face the Z axis. Catalyst seems to orient the model towards the Z axis.
If you're still having problem try outputting your model without any shading or bump/displacement.
Z axis on many modeling packages is not height it is depth as in from the cameras point of veiw. Only in architectural and 3dmax is Z up and down. You can change this preference in most packages so that Z isup.

I know that if you follow these steps your model should work. Experiment though in your spare time and try all types of geometry and faces. I'm not saying that they won't work, I just know what will.

Anyone with any in depth 3d questions, feel free to pm me and post here.

Christian

[joshgubler]

I have a very simple arc I'm looking to shoot onto. Here's the setup:

3 projectors tiled (not blended) shooting onto a single arc (120' long w/ 70' radius). The projectors are each centered and squared up with their individual portions of the screen, so you could basically treat it like 3 separate and identical arcs. The "screen" is actually a curtain with fullness, so that will cover a little bit of distortion.

Do I need to create a model for this arc, or will catalyst handle the curved surface through internal settings (i.e. mix settings, etc.)?

Thanks.

[litemover]

Definitely use the curved screen submix. It's very reliable, I would try to get a Triplehead2go on it so that you can just use same layer and it will be guaranteed to stay in sync.

This way you could control the 3 way tile with one long piece or 3 separate pieces if you want. If you don't need to spread one image all the way across, I would still use the internal curved screen control on the submixes that you are needing for and use 2 machines for it, unless of course it is a very small resolution screen...

Alternatively, if you need absolute seamless screen blending with point control for luminosity, you could use a Spider but to me it sounds like Submix curve screen would work just fine in this situation. Even Catalysts Blending is completely and totally awesome, stack right up to a spider with a few small exceptions.

Hope this helps

Kindly,

Christian Choi

[joshgubler]

Thanks Christian,

The triplehead solution is exactly what we have planned. If it was just three separate images then distortion at the edges wouldn't be such a big deal. It's because we want to throw a panoramic image up on our panoramic screen that it has to be relatively clean. I'll play with submix curves. Thanks.

[SourceChild]

I think edge blending would be cleaner...
...my designer has done a test shoot...afraid of loosing intensity by having to spread each of the projectors...

Trust me on this, if you can blend, even a little bit, it will look so much better. With even the slightest overlap of two butted edges, your intensity increases and it is very noticeable.

...3 projectors tiled (not blended) shooting onto a single arc...
...120' long...

Something of a concern, you mention 120'. That would mean a single projected image size of 30'x40'.
I am not sure what projectors you are using but that is a huge image.

I typically use LX-100 10k projectors and the largest size I would ever shoot is 18'x24' and that is in low light. Even if you are using a 20k projector, 30x40 is still huge and will only be about a tenth as bright as a typical screen.

If you're worried about running everything off of a single Catalyst, remember you can use 2 TH2Gs and run 5 projectors and put your HUD on one of the six outputs.

I have some intensity equations if you're interested.

[litemover]

Catalyst Blending works great, even at high Def.

If you need it to look better, work with the projectionist to do a dual blend between the projectors and Catalyst simultaneously, set a blend of around 20 to 35%, leave up the alignment marks then let the projectionist work out the rest of it.

If you are working in an extreme situation with a rediculous amount of souces that need to blended, composited, PIP, pixel adds, etc..., and don't want any hastles, USE A SPYDER and don't cheap out.

You can see everything that a Spyder does here: Vistasystems

For most cases though, Cat edge blending and a combination of projectionist will/knowledge will go a long way so treat your projectionist with class.

CC

[joshgubler]

Thanks for your concerns, SourceChild.

We did the show back in Sept. It went really well. I'm pretty sure the projectors were 21k. Plenty bright for the live audience, but a little dim on camera. It would have been nice to have them doubled stacked.

As I mentioned earlier, our projection screen was actually a white scrim curtain with fullness. Because of that, the edges were undetectable. Seriously, I had trouble finding them sometimes...and I knew they were there!

As far as alignment goes...catalyst's "curved screen test" works great. I just had the projectionist center each projector and fill the screen with the excess shooting beyond the screen. Then I tweaked the control points until everything lined up. Piece of cake.