Slab Hatch Patterns: Hatch pattern unexpectedly changes for slabs with the same style (Concrete Slab on Grade).

[robertekimble]

Problem: The slab hatch pattern appears to change based on an area threshold and I don't understand how to control this display property. Sample files attached.

Background: I have been away from Autodesk products for about 13 years. I am learning Autodesk Architecture and working through a 30-day trial. Many advancements have been made and a lot of things are the same.

As I have been working with the slab tool, I have encountered a discrepancy in the way hatch patterns are being displayed in the drawing. I started a new drawing and replicated the problem. The slabs are assigned the stock Concrete Slab on Grade style from the Imperial Design Tool Catalog. The view is set to High Detail.

 I don't understand what causes the hatch pattern to change, but I have found that altering the area of the slab will cause the change to occur. I have attached a drawing file, Adobe Acrobat printout, and screen capture of the style version history. 

I've spent hours trying to figure this out. Any insights or explanations would be much appreciated. 

[dbroad]

Problems in the file:

1. You are using a wireframe visual style.  This shows the subgrade hatch through the slab, where it can.

2.  You've messed up the high detail display configuration by choosing NONE for the top DR. The top DR wouldn't typically shown any hatch but could be made to do so.

The reason that the subgrade hatch shows when the slab is small and not when large is due to the permitted number of maximum hatch lines as controlled by HPMAXLINES.   AutoCAD is working in an optimized fashion. Trying to display more than 100,000 lines (Standard HPMAXLINES setting) is inefficient and leads to slow display performance.

HTH

[R_Tweed]

Based on the dwg, There are a couple of things to consider.

1. Display representation based on scale of drawing and settings in the display manager. is 1/32= low, 1/8"= medium and 3/4"=high. model is for modeling except in certain object types.

2. Material settings based on display representation.

3. Slab style and it's display of each component for each display representation.

I've added notes of changes made to your slab style, material and display representations that I think would be helpful. to answer the original posted question. @dbroad is correct that hpmaxlines is what causes the larger slabs hatch to disappear.  My thought is that hatch patterns are meant to provide visual feedback for a material and do not need to be dense enough to appear as a solid. Use a larger scale for your hatch pattern and or something with less definition unless you are working on a detail.

[robertekimble]

Hi Doug. I really appreciated the response. That makes perfect sense. I definitely need to spend some more time with display configuration settings too. To learn, I was mocking up a building using an old set of plans from the 80s. I did figure out how to create trapezoidal-section strip foundations by extrusion. I have that going for me. Including rebar in the section, not so much. I think that's probably a problem for Revit?

Efficiently going from computer to paper is somewhere next on my list. Do you prefer color or style-based template files when you start a project?

For now, you'll probably find me in the MEP forums, or Electrical.

Thanks again!

[robertekimble]

That was super helpful, Robert! Much appreciated. I have a lot to learn in order to go from AEC object-based models to paper. It seems part of the trick is getting the Display Manager settings dialed in. It's probably pretty efficient once you have a good system in place...

I was really wrapped around the axle with a phantom line showing on structural beams/columns in Model space/Medium Detail/2d Wireframe. The objects did not have any active display property style overrides. I realized the line always followed the assigned baseline, but the line still appeared if I turned off every layer in the Display Manager under the related Display Configuration (including the Axis).

Long story short, I had applied a material to the style and the "baseline" that I kept seeing was associated with the material applied to the structural element.

Many, many hours of Google. Then clicking. Then Google. Then clicking... I didn't engage the forums, but I did self-solve.

Again, thank you very much for your input! I'll probably be over in the MEP or Electrical forums for now as I'm getting acquainted with those platforms.