Help with Instancing in Softimage XSI

synergy11

Hello I've been following a tutorial on making a brick floor that involves sculpting a few High poly bricks in zbrush than bringing those into 3d package to Instantiate into a modular floor piece, to then create a low poly mesh around the whole thing to bake.

I'm aiming for 16 bricks in total.

However the poly count is 1 million per brick so it's not working out too well :x

However the author of the tutorial says as long as you instantiate your bricks it should be less of a strain on the system.

I tried creating the model and instantiating it but I crashed after a few bricks.

Any help will be great.

I'm at work and cannot post pics but I will later.

Thanks!

synergy11

Here is an example of what I am trying to achieve. It's the fourth image down. (The Floor model breakdown)

http://www.polycount.com/forum/showthread.php?t=83186&highlight=orb

That artist made the high poly floor piece with 5 slabs made in zbrush....

Thanks.!

cryrid

The mesh has to be in a model container first (select the object, and under the model toolbar choose Create>Model>New Model). Select the model in the explorer and hit Ctrl+i to create an instance based on it. You can translate/rotate/scale/duplicate the instance as needed. There are also several Instancing options in the file menu under Edit>Duplicate/Instantiate.

Just add all the instances and the original model to a group, and use the group for Ultimapper's high resolution source when baking your maps.

(Side note: You may also want to try using Zbrush's Decimation Master to get the brick down to a lighter polygon count. Ultimapper can read displacement maps on the high res source as well).

synergy11

Hey I tried your method and it worked perfectly on the original model.

But when I add the original brick to the 3 instances than create a group. Ultimapper renders a blank blue map.

I selected the group node in the Explorer by picking it from the Ultimapper Hi res source.

Heres the pic of the setup.

http://img859.imageshack.us/i/ultimapperhelppic.jpg/

This pic shows it working when I just pick the first brick (original model)

Thanks!

edit: for some reason the instances are not rendering to the map. I also discovered in the explorer that there are other group nodes hidden in the original object... I tried selecting those as source but still only original brick renders.

cryrid

Does that portion of the low-res mesh have UVs, and have you tried automatically computing the distance to surface instead of using 0?

synergy11

Yes I type compute than generate.

The LP plane has uvs.

Thanks

cryrid

Sorry, I missed your edit that explains you only had the first brick selected.

edit: for some reason the instances are not rendering to the map. I also discovered in the explorer that there are other group nodes hidden in the original object... I tried selecting those as source but still only original brick renders.

What does your explorer look like with all the nodes/groups expanded? Be sure to middle-click the instances and models in the explorer when adding them to the group.

If that fails, create a new scene and try setting it up again (using simple spheres instead of the highpoly bricks). Should that not work, save that test scene and send it to me so I can have a better look how it is set up.

synergy11

Dude I owe you sooo many beers.

Thanks!

It looked like selecting the models with middle click before creating the group fixed it.

Why the middle click?

Thanks again!

cryrid

Left-click selects a single node/object (in this case the root), middle-click selects the branch (the object + all it's children)

synergy11

I decimated all the bricks to around 400,000 and assembled 12 of them in XSI.

However I am trying to create a low res mesh around them at it's running waaay to slow.

So I decided for the purpose of creating the low poly mesh I was going to use the polygon reduction function in Softimage. Then build the low res mesh around those poly reduced bricks. However it's not in my menu??

Modify>PolyMesh>Polygon Reduction. Its supposed to be there but its not.

Any Ideas?

I have version 6.

Thanks.
Chris.

cryrid

I'm not sure why it's not there, even the older versions should have it (I recall v5 having it).

Since you're running into performance issues: as far as retopologizing a new low res mesh goes, you don't need the surface detail of even the 400k decimated brick; you just need the basic form/silhouette. So just export one of the lower subdivision levels and use that as your guide instead.

synergy11

I tried to build my low rez mesh in XSI by building poly by poly around my med rez mesh. But man xsi a bit wonky with that.

I think I'll use zbrush's retopo tools. They look like they work well . Sticking to the surface of the hi rez mesh and all...

Cyrid. what do you use for retopo? Softimage?

3d Coat looks cool. But Zbrush tools look on par with that.

What is your opinion?

Thanks

Chris.

cryrid

I just stick with Softimage. Surface snap + Shrinkwrap works quickly enough for me.
http://cryrid.com/art/?p=60

Mark Dygert

I would back the train up into the station again... Each brick being 1million polys (2million tris?) Think about the level of detail you created and the level of detail you will bake.

If you put a city block on the head of a pin and step across the street to take a picture of the pin, you're not going to see the city block... you won't even see the pin.

Also... http://www.zbrushcentral.com/showthread.php?t=071265
Aslo.... http://www.topogun.com/

synergy11

Thanks for all the feed back folks

The surface snap tool in Softimage is working as expected now. Maybe it was because before I did not make my hp mesh unselectable.

And basically what Mark Dygert is saying is that very fine details will not even show up in a bake. So why bother with the wasted time and head ache of working with such objects!

pasha_sevez

cryrid wrote: »

I just stick with Softimage. Surface snap + Shrinkwrap works quickly enough for me.
http://cryrid.com/art/?p=60

Yes, this works fine for me too. Also unlike topogun it give you an ability to use all SI tools to retopo your model - that's cool!