Model Building

[IvyTechEngineer]

On 5/22/2022 at 5:49 PM, Aquila Kytori said:

The complete board is 3079 triangles  ( the base board by its self is 228 tris ) :

 

Do you have a Second Life Marketplace or would you be willing to sell your model? I still want to see what I can do but there is so much I don't know right now. This sounds like a cop-out but it will probably take me another couple of weeks working on this over my summer break. 

[IvyTechEngineer]

On 5/22/2022 at 5:38 PM, Aquila Kytori said:

The reason I suggested assigning the board to a vertex group was, as I had thought I had explained, so that you wouldn't have to try selecting all the boards vertices in one go (which could be tricky) so that it could then be separated to be its own object. Instead you could select some vertices > assign them to a Board vertex group, > select some more board vertices > assign these to the Board vertex group, > repeat until all the boards vertices had been assigned to the Board group. Now, to select all the boards vertices you just have to go to the Vertex Group panel > select the Board vertex group and hit the Select button at the bottom of that panel.

If you want to create a library of models, textures etc,  then you would use the new Asset Browser feature:

 

Its disappointing that for such a simple shape you have to "do some more searching to see how I can add them back."

Some options for adding back the pins :

1: Edit mode > select a pin from another component >  Shft D to make a duplicate > move duplicate to correct position and  resize if necessary. Duplicate this new pin and move to approx; correct position for the next pin. Duplicate and move for the other missing pins.

2: Create from scratch,  Edit mode select a nearby vertex > duplicate it > move , extrude etc to build up a pin. Duplicate this new pin and move to approx; correct position for the next pin. Duplicate and move for the other missing pins.

3: Edit mode, Position 3D cursor to approx correct position > Shft A  and Add a new mesh cube > resize etc........... Duplicate this new pin and move to approx; correct position for the next pin. Duplicate and move for the other missing pins.

4: Open the original Arduino model > Edit mode Select the missing pins > duplicate > P to separate to be a new object > Object mode > select the new "pins" object > Ctrl C to make a copy  > return to (or open) your new "Optimised Arduino" .blend > Object mode > Ctrl V to paste   (it should be pasted into the correct position) > Select the new "Pins" object then Shift select your partially  "Optimised " board object and use Ctrl J to join so that the pins will become part of the "Optimised" board.

Note that the exact position of pins/components will be determined when you have the top surface of the board mapped to a texture. They will need to be aligned to the solder pad positions of the texture on the board.

And you don't have to be very accurate in the dimensions of the pins. See the image below for a comparison between an actual reset switch pin relative size and the pin size in the original model.

 

The mistake that you made at the very beginning is that you should have made a copy of your original Arduino .blend file using the Save as option, then in this new file Object mode > Shft D to make a duplicate copy of the original board and worked on simplifying this copy. Doing it this way means you would still have the original board in the same .blend as your simplified board which would have been useful for when you make errors like this (deleting parts by mistake) You could easily copy and paste from original to simplified model.

Nothing to stop you now copying and pasting a copy of the original board object into this new file:

 

I had hoped to maybe take a Blender class this summer (wanted a class that aligns with making things like the Arduino, DC Motor, etc). I am sure there are many gaps in my understanding. I am self-taught and of course this makes it ineffective and I ask a lot of questions. Also, I use Blender sporadically so I need to be reminded of things that I saw before. My object is really to build things that I can use in Second Life for teaching.

A while back I stumbled across a great article - Engineering Education Island: Teaching Engineering in Virtual Worlds and asked the author for suggestions because I wanted to build a virtual learning environment for my school. He said that they had stopped using SL because of the cost increase back in 2012 or so. Many educators left SL at that time. I recently did a survey and found that only 15% of the educational sites listed on the https://wiki.secondlife.com/wiki/Second_Life_Education_Directory still have some sort of presence in SL. That is a tremendous decline. 

My end goal is to build a virtual cleanroom. I have Maya models for much of the equipment and will be going to UNM to get the rest of the info to build the cleanroom this summer. In the mean time I am attempting to learn as much as I can and create course content that I can use in my engineering classes.

I wanted to thank everyone for their help and your suggestions. It is much appreciated.

ivytechengineer

[Aquila Kytori]

I have to work on some lower LoDs first. When done I will and send you a copy inworld along with a note card with a link to the .blend, probably Monday.

[Aquila Kytori]

On 5/29/2022 at 12:35 PM, Aquila Kytori said:

I will and send you a copy inworld along with a note card with a link to the .blend, probably Monday.

Sent

 

[IvyTechEngineer]

On 5/29/2022 at 6:35 AM, Aquila Kytori said:

I have to work on some lower LoDs first. When done I will and send you a copy inworld along with a note card with a link to the .blend, probably Monday.

Thank you so much. I received the models (three of them) and two textures file but didn't see the notecard for the location of the blend file. Thank you so much for all of your help, this is awesome!

[Aquila Kytori]

To close the Arduino chapter of this thread , the lower LoDs :

 

Using the LoDs above :

Board size approx. :  1.5m x 2m   =  LI 1

                                     2m x 3.2m   =  LI 2

                                    4m x 6m       =  LI 6

                     

       

Edited July 2, 2022 by Aquila Kytori

[IvyTechEngineer]

Hello

It has bee a little while since I used Blender last. I wanted to use some of the STL files that my students created in Solidworks and convert them in Blender. I believe this was the primary reason why I had to use Blender. Anyway, if I have a model that has been scaled in Blender how do apply the scaling to get the scale back to 1?

Thanks

[IvyTechEngineer]

I figured it out, thanks

[IvyTechEngineer]

Hello again,

Got a question for you about models that have already been uploaded. Is there a way to review the Physics info for the model?

Thanks 

[arton Rotaru]

1 hour ago, IvyTechEngineer said:

Hello again,

Got a question for you about models that have already been uploaded. Is there a way to review the Physics info for the model?

Thanks 

If by review you mean to change/edit the physics model of the mesh asset, then that is a no.

[IvyTechEngineer]

Hello again,

I often review past post to see if I can figure out stuff for building things for Second Life. I really appreciate all the help I have gotten from everyone since I started. I have an STL file that is massive in size when imported into Blender to create the DAE file for SL. It requires a 0.004 scaling to get to a 1 meter size. I seem to remember that once you rotate or scale an object in Blender you need to do something to lock the scale in for the object. Does anyone remember the command in Blender? Also, I was trying to merge two objects: the skull and jaw of a T-Rex model I found online and wanted to merge them into a single object in Blender. The origins and orientations for the are way off. When I tried to export to a DAE file it only export the skull. Not sure what happened or what I did wrong. Is there some sort of command to merge objects before exporting?

Thanks

IvyTechEngineer 

[Aquila Kytori]

3 hours ago, IvyTechEngineer said:

I seem to remember that once you rotate or scale an object in Blender you need to do something to lock the scale in for the object. Does anyone remember the command in Blender?

Object mode > Select Object > Crl A to open the Apply menu > choose the All Transforms option.

 

3 hours ago, IvyTechEngineer said:

Is there some sort of command to merge objects before exporting?

To merge (Join) 2 separate objects so that they become 1 :

Object mode > select both objects > Ctrl J to join them so they become a single object.

After joining use  the Apply > All Transforms option.

 

[IvyTechEngineer]

Just now, Aquila Kytori said:

Object mode > Select Object > Crl A to open the Apply menu > choose the All Transforms option.

 

To merge (Join) 2 separate objects so that they become 1 :

Object mode > select both objects > Ctrl J to join them so they become a single object.

After joining use  the Apply > All Transforms option.

 

Thanks! 

You help is always appreciate Aquila.

[IvyTechEngineer]

Hello

I have been working with a CAD program Solidworks and Blender to develop models for Second Life. Early on in my post in the thread, I asked questions about reducing mesh density. The process is to create an STL file with Solidworks, importing it into Blender to scale and reduce the mesh, and then exporting it as a DAE file for Second Life. I was reviewing the BCC crystal unit cell model I create a while back and noticed that when the STL file is created in Solidworks it creates a model it says the it should only have 746 triangles but instead, it has 8302 triangles. Not sure what is doing. Then I found this excellent YouTube video that allows you to create low mesh models with Solidworks. 

In Blender, I just did a shade smooth in object mode with normals. However, I still had a few questions about how to reduce the mesh with the original model. 

The next question goes back to an earlier version of the mode and reducing the mesh. I can

1.) merge vertices

2.) I can use the approach discussed in Bryson Jack's video using the Checker Deselect in Blender

However, I am unsure how to align a vertices so it would follow the contour of a sphere. If I could figure that out I think it would help.

Thanks

IvyTech

[Aquila Kytori]

1 hour ago, IvyTechEngineer said:

The next question goes back to an earlier version of the mode and reducing the mesh. I can

1.) merge vertices

2.) I can use the approach discussed in Bryson Jack's video using the Checker Deselect in Blender

However, I am unsure how to align a vertices so it would follow the contour of a sphere. If I could figure that out I think it would help.

 

If you mean how is Bryson Jackson selecting the original ring of edges at 1:16 in the video............

You have to be in  edge select mode. (see screenshot below).

Note tha Bryson is using and older version of Blender so when he says use Right mouse button to select the edge you will use the Left mouse button

 

[IvyTechEngineer]

Sorry, my question was poorly stated. I want to reduce the mesh by following Bryson's approach but feel like I clean up the mesh first for the various spheres.

The mesh I am using starts at 8286 for mesh simplification of just one side of a bottom partial sphere it is reduced to 8276 tris.

The first thing to do would be to merge some vertices around the edge of the partial spheres. Next, I can use the slide vertices to move them so they align around the partial sphere edge. 

Sliding the vertices does not reduce the tris per se, it just makes the sphere look better. 

This was really my question. How do you move vertices along a circular edge so they align with the sphere contour?

Thanks

[IvyTechEngineer]

I can also clean up the mesh by merging vertices by distance and then use Bryson's approach to reduce the mesh. I think, lol

[Aquila Kytori]

As a general rule, when bringing in a mesh from another programme start buy converting the triangulated mesh to quad mesh.

This will make the mesh simpler to edit (and make it possible to select vertex, edge or face loops/rings).

 

To slide an individual vertex along an edge and have it automatically merge to another vertex, first enable Auto Merge Vertices,  then select the vertex, hit the G key twice (this enables the vertex slide mode) and move the mouse towards the vertex you wish it to merge to. The first vertex will now be merged to the second.

 

An alternative to slide and auto merge is to First select the vertex you want to merge and Shift select the vertex you want to merge to, then hit the M key (Merge menu) and chooose the At Last option.

Edited to add:

Just reread your question, the answer to  :

17 hours ago, IvyTechEngineer said:

This was really my question. How do you move vertices along a circular edge so they align with the sphere contour?

is G G

With the vertex selected press the G key twice and move the mouse in the direction you wish to slide it.

Edited January 23 by Aquila Kytori

[Aquila Kytori]

A rough and ready way to reduce vertex count using the Decimate tool. (or Modifier) :

 

 

[Luna Bliss]

1 hour ago, Aquila Kytori said:

A rough and ready way to reduce vertex count using the Decimate tool. (or Modifier) :

 

 

Do you usually find that to be enough, or do you also retopologize?  I mean, we don't have to be perfect right?   Too much trouble for me to be anyway.

[ChinRey]

5 hours ago, IvyTechEngineer said:

The first thing to do would be to merge some vertices around the edge of the partial spheres. Next, I can use the slide vertices to move them so they align around the partial sphere edge.

Just a quick comment without reading the whole discussion (sorry, I'm a bit busy atm). Normally the edges are the last place you want to simplify a curved surface because that's where the angles between the vertices are most visible.

[Aquila Kytori]

12 hours ago, Luna Bliss said:

Do you usually find that to be enough,

I never use the decimate tool.

I just enjoy the process of creating mesh so don't usually mind doing stuff the long way round.

[IvyTechEngineer]

Hey, thanks for your comments. It seems like I always get stuck in Blender trying to reduce mesh models that I import, lol. I have used the decimate modifier before and that sometimes leaves me feeling like the mesh could be better. I think most of my issues come from using a CAD tool like Solidworks but there is a way to decimate in Solidworks as well which will reduce the total number of tris. I can precisely draw almost anything in Solidworks so I am biased. 

Recently,  I have been revisiting some of the stuff I did when I got started with building models to see if I could understand and improve the models and workflow. Thanks to you guys I have learned a lot and continue to explore building more and more models for Second Life. 

Regards

IvyTech

[IvyTechEngineer]

I was experimenting with a partial model of my BCC model and noticed that the model had 

• Vertices = 1553
• Edges = 4647
• Faces = 2098
• Triangles = 3098

The after the Alt-J, manual mesh cleanup by merging vertices, dissolving edges, etc.., and deleting every other edge loop I was pretty happy but still had some non-symmetry in the mesh. 

• Vertices = 395
• Edges = 828
• Faces = 437
• Triangles = 789

Is there away to evenly space vertices around a circle? Also, I still don't understand why the STL file has so many issues with it's geometry. along some of the cut edges. 

 

Thanks

IvyTech

[Aquila Kytori]

12 hours ago, IvyTechEngineer said:

Is there away to evenly space vertices around a circle?

Yes, using the Loop Tools addon that comes with Blender.

Edit > Preferences > Add-ons > Search for Loop Tools and then enable the add-on:

 

To space the vertices evenly aoround the circle:

in Edit mode, first select the circle next RMB (right mouse button) in the viewport to open the context menu. From this menu choose Loop Tools then Circle. This will arrange the vertices to form a circle and all the vertices will be evenly spaced. 

 

Note: you can also find the Loops Tools options in the N  right hand side panel  :