solidifing objects for extrude/rendering

[JBender]

I am working on modeling some industrial equipment that we build. We currently have 2D drawings which I am converting.

I'm hung up on how best to create a solid object from several lines, arcs, and the like. They are all connected, but I'm not sure how to designate the whole as a solid.

I understand that in many cases folks will create inverse 3d objects, and subtract the extrudes. In my case, such as an end plate with curved corners, and odd shapes - that method is not ideal...

How have others gone about this? Is there a tool that I can "outline" my other objects, and create a solid that I am missing? Some command to "join" 2D objects into one?

Another question I have has to do with rendering. I notice that if there are many objects to render when I use the flyover tool - the rendering reverts to wireframe. Is there a way to change that threshold? Also, is there a way to render in hidden line, while using flyover. I find it easier to see what i am doing if only the rendering would continually update and display. We have fast computers nowadays, why would this be a limitation? Is there a product I should be buying to give me this capability?

[JBender]

To answer part of my own question, one method is to use the 2D polygon - "create polygon from inner boundary" tool. Works great. I supose the polyline tool could work if only the "from cubic spline" worked intuitively. I guess I don't know what a cubic spline is....

[Dave Donley]

Hello Jhaceun:

The OpenGL render mode will show interactive rendering with the flyover tool if the model renders fast enough to be interactive. The VW Preferences->3D->3D Rotation preference sets the threshold. Also make sure the Retain Rendering Model preference (in the same location) is not set to "Never" - this would disable interactive rendering during flyover.

OpenGL can show edges like hidden line, enabled in the View->Rendering->OpenGL Options. These will be shown during flyover if they can be rendered fast enough to be interactive.

Edited January 15, 2008 by Dave Donley

[Damon Design]

As noted above - Use the polygon tool, paint bucket option-create polygon from inner boundary- to achieve the "outline" (actually inside) a series of connected lines and arcs, just click the paint bucket icon inside, as long as the area is truly closed the resulting polygon can then be extruded to a 3D object.

Make sure the layers visibility is set to active only, this should force the solid model to stay rendered during flyover in Open GL as long as it is not too complicated.

Edited January 15, 2008 by Damon Design

[Pat Stanford]

Another question I have has to do with rendering. I notice that if there are many objects to render when I use the flyover tool - the rendering reverts to wireframe. Is there a way to change that threshold? Also, is there a way to render in hidden line, while using flyover. I find it easier to see what i am doing if only the rendering would continually update and display. We have fast computers nowadays, why would this be a limitation? Is there a product I should be buying to give me this capability?

In your VectorWorks Preferences under the 3D Tab you have sliders for 3D Rotation and Retain Rending Model. Slide the Retain slider to the right to keep the model more often.

VW tried to compromise between a reasonable flyover speed and keeping the model rendered. It will also depend on just how complicated your rendering is. Turn off anything (classes, layers) that you don't need to see and you will get better performance.

Pat

[JBender]

Thanks for the tips with rendering. It seems to be rendering during flyover so far. We'll see what happens when it gets complex. I knew about the rendering settings, and have them pegged. I didn't know about the openGL hidden line option. I will be looking into that.

I have had good luck rendering (square) solid objects out of whatever I want now, so that is a relief. I do have a challenging opject to render, and I'm looking for suggestions. I have a spocket I'd like to render. I can take the 2D side view, and extrude that easy enough. The challenge is in the tappered teeth on the sprocket (a sprockets teeth get thinnner toward the outside). Any ideas. I'm sure this is one of many rendering challenges I'll face in machine design. Is there a better forum to post rendering challenges?

Edited January 15, 2008 by Jhaceun

[Pat Stanford]

In rendering your sprocket, try thinking out of the box. What is going to be easier to make, the positive you are trying for, or a negative that you can use to subtract to get your final result.

For a set of teeth that need to taper, I would draw a polyline/polygon that has a cut on one side that gives the tooth profile needed (think of a box with a notch on one side). Sweep this around the center of the sprocket to get a doughnut with the notch on the inside. Then line it up with your extruded sprocket and Subtract Solids. You should end up with a sprocket with tapered teeth.

If you need a more complex tooth, try making a single solid with a cutout that give the right tooth and then duplicate array is around to every tooth. Then do a single subtract solids to get the final sprocket.

Regards,

Pat

[JBender]

Thanks, Pat, I'll try that.