2D heatmap from points from a drawing

[johnsmith6208]

Hi I got an area where I have done a lux survey, for simplicity the area is a rectangle with lux level points below the  crosses as shown in the file below. How would I go about constructing a 2D heat map with scale of 15 being red and 2 blue?

[Washingtonn]

Using only AutoCAD, I would approach it much the same as a contour map with the lux values used as the elevation contour lines (you may have to adjust the vertical scale, such as making 3.4 = 3400). Create a solid from the lux location information and slice at the desired "elevations". Change the contour color or making gradient hatches between contours after flattening as required.

[leeminardi]

The general strategy to create the heat map you seek using AutoCAD is to:

1. Add a Z coordinate to your "point" data.
2. Create a surface from the point data.
3. Apply a blue to red gradient map material to the surface making sure that the plane for the material map is oriented veritcally and it is scale so that its blue end is at the bottom z coordinate of the surface and it red end at the top.

I created points from your data and then made their z coordinate  equal to the text value (temperature?).  The resulting relative displacements of the points in Z are much less than the X and Y separation so for better clarity I created a block of the points, scaled it by 1 in X and Y but 1000 in Z and exploded the block.

3Dface objects were then added to create a surface.  This is a relatively fast process to do manualy. 

I wanted a single object for the surface to apply the material to so I converted the collection of 3dfaces to planar surfaces with planesurf.  Union was then used to make a single object from the planar surfaces.

A material was defined from a blue to red graient map I create in Power Point.

The materail was then applied to the surface.  The user interface in AutoCAD for adjusting the size, orientation, and location of the mapping gizmo is AWFUL!!!  I was able to get the gizmo close to the correct size and orietation. In the following image you can see the planar material mapping gizmo and the 3D surface.  I used the box to help me scale and located the gizmo.

Here's a top view, the 2D hheat map I think you want.  I am not sure what is causing the red spot.

Once you have a 3D surface model you can use section to create contour lines. I created a few as you can see here.

The above process was done entirely within plain AutoCAD.  CReating a surface fro point is easier with Civle 3D and material mapping is much easier with 3ds Max.  I'm sure that there are other programs that wuld simplify this process.

[Washingtonn]

Method to create contour only lines from lux reading between 2 and 15, but without color gradient.

[leeminardi]

@Washingtonn Nice illustration.  Note, you do not need to create a solid model if you goal is to get contour lines.  Just use section with the surface model.  It's easy to  specify the elevations for the contour lines.

[Washingtonn]

Thanks Lee. I was experimenting with gradients in AutoCAD on sliced solids and continued on to get the contours from the slices. Will have to try the sections with a surface model.