Walkable stairs.

[Ark Vuckovic]

Hello,

I am trying to make a house base with the stairs attached in Blender, as you see on the snapshot. After I uploaded it to SL I discovered that I can't walk on the stairs up. I applied physics to the mesh and set it to prim. The physics is a separate prim with simplified shape it has a ramp in place of steps. But when I start to walk, the mesh prim acts as a phantom object. Instead of walking up the stairs I walk right inside of the prim. I tried to use the same mesh for physics, but the result is the same.

Any suggestions how to make it work?

[Johan Laurasia]

The easiest way is to take a separate, single "regular" prim and make a flat ramp that you lay just above the stairs at the angle of the stairs, then make the prim invisible.  This will give you a flat surface that an avatar can walk up and will be silent as well.  Stairs that are physical go "bump bump bump" as you ascend/descend the stairs, where the flat invisible plane can be either silent, or if you want to get fancy, use a collision detection script to trigger the sound of someone walking up stairs.

[Ark Vuckovic]

Your suggestion defeats the purpose. I know that trick too. But trying to save some prims in here.

Thanks for the reply:)

[Rolig Loon]

Unless you're unlucky, linking a prim to that mesh won't increase the L.I. of the linkset.  Try it and see. 

[Frawmusl]

Have you attempted making custom physics rather than just working with the generated physics?

[Ark Vuckovic]

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Rolig Loon wrote:

Unless you're unlucky, linking a prim to that mesh won't increase the L.I. of the linkset.  Try it and see. 

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You mean to make a prim in Blender and link to the other object? Or do it in SL after uploading?

[Rolig Loon]

I mean just grab a regular garden-variety flat prim in world and link it to the mesh.

[Chic Aeon]

So there are a couple of things that might help you out.  I don't really like making whole mesh houses, but I did do it as an exercise once - ONCE . What I found after much frustration is that sometimes you are really better off with a plain old prim *wink*.

 

Now I understand the purist point of view, but if you are looking for practical ----  here are some hints.

A plain or regular cube prim when changed to CONVEX HULL in the FEATURES tab of the build menu is .5LI. Now if you do something fancy to that "plain cube" prim the physics can change. I linked some mesh to a hollowed prim one time and the LI doubled LOL. So a regular plain cube. A plain cylinder (in my recent test anyway) acts the same way and is .5LI.

These old fashioned, bless their hearts, prims hold their LODs for-e-ver (well more or less) AND they can be any size and still be .5LI. So in many cases you are better off with a plain prim for a floor for example. Easier, less issues with physics AND less likely that the server will change the way it interprets your floor (that has happened in the past).

If you are baking complex textures you can still do that and use the baked texture on your plain prim.

What you DON'T want to do is connect mesh to sculpts. This often if not always raises the LI by a bunch (and I do mean a bunch).

Also you can keep your LI down by uploading (when it will work for the design) in parts rather than trying to make the whole build as one joined object. So modular is a good thing oftentimes.

 

[Drongle McMahon]

Not really enough information here to know what the problem is. Can you give a more detailed description of how you "applied physicsto the mesh" and what you maen when you say the physics is s separate prim? Also, if you can, make a screenshot of the physics shape after Develop->Show Metadata->Physics shapes.

[Johan Laurasia]

Sometimes you have to use a prim to save using more.  Adding 1 to LI is cheap fix cost wise.  Any physics method is going to drive up the cost much more, especially considering your stairs can be a quarter sim square and STILL only have LI of 1.

[LepreKhaun]

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Ark Vuckovic wrote:

Hello,

I am trying to make a house base with the stairs attached in Blender, as you see on the snapshot. After I uploaded it to SL I discovered that I can't walk on the stairs up. I applied physics to the mesh and set it to prim. The physics is a separate prim with simplified shape it has a ramp in place of steps. But when I start to walk, the mesh prim acts as a phantom object. Instead of walking up the stairs I walk right inside of the prim. I tried to use the same mesh for physics, but the result is the same.

Any suggestions how to make it work?

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Are you using Analyze and Simplify on your physical model when you're uploading your own dae file for it? SL may optimize key elements of your model away when you do that.

[Aquila Kytori]

hi

As drongle has already said you need to at least post a screen shot of the inworld physics shape . I made a workflow tutorial so that maybe u can see where your going wrong :

1: Create your mesh and export as a  Collada file   ( House-base.dae )

2: Make a very simplified version of the original mesh using non-overlapping boxes and export as a Collada file ( House-base Phys.dae ) This will be used for the Physics shape of your house-base mesh in the mesh uploader .

 

3: In the mesh uploader select your House-base.dae mesh

4: Next open the Physics tab of the uploader and in Step 1 choose From file, then  select the House-base Phys.dae file .

5: From Step 2 hit the Analyze button.

6: Calculate and Upload ............

7: Rez the House base mesh, being carefull not to rez it on top of yourself of another avatar because this can mess up the physics.

8: Edit the mesh and in the features panel change the Physics Shape Type to : Prim .

 You should be now able to walk up the stairs and onto the platform

If you can't then  check out how the physics looks by going to the Develop menu > Render Metadata>Physics shapes and

take a screen shot and post it here .

[Ark Vuckovic]

I did all of the steps you have mentioned in your message. Except on the railing I didn't followed the shape on angle. Would this make any difference? Here is my picture showing the metadata. It's not blue:( as you can see it.

[LepreKhaun]

Defining the railing as you did will work but it is necessary to have the angled Ramp where the steps are in your physical model: From Aquila's excellent illustration:

 

 

If you're lacking that, your stairs would appear phantom.

[Aquila Kytori]

For anyone coming across this post in the future the problem was apparently caused by rezzing the mesh over an avatar which sometimes messes up the physics.

When I first experienced this problem on Agni, even taking the problem mesh back into inventory and then re-rezzing well away from my avatar didn't always result in a physical mesh. Sometimes it remained "phantom" to me but physical to other avatars then after another re-rez or so it would be fine .

[Simona Erin]

 You are the best:-)). Thank you very much, helped me understand where I'm wrong :-))