extrude polygons based on texture map

[tarkovsky]

Hi all.
I'm trying to extrude polygons depending on texture map color. I have a black and white texture map, and want to extrude all the "black polygons", but I'm a bit at loss.
Here is what I have so far...



Result should be something like this (final application is a sphere)



thanks for any help

[jonmoore]

From what I know, even with ICE Topology, you can only extrude poly's based on clusters not a weight or color map. Within the ICE Topology toolset there's a compound called Apply Extrude along Axis, this will procedurally extrude cluster selections. You'll need to paint your cluster selection based of your texture map, but that's easy enough.

http://docs.autodesk.com/SI/2015/ENU/#! ... g_Axis.htm

If you've not done anything with ICE Topology before, you should definitely read through the guide pages first as it has a set of quirks all of it's own.

http://docs.autodesk.com/SI/2015/ENU/#! ... 05F70D.htm

[jonmoore]

It occurred to me this morning that you could use the emTopolizer addon to extrude your geo if you first convert your texture map to a weight map.

Basic workflow as follows:

Conversion of texture map to scalar data that can be set to weight map data (ignoring the final set data attribute, you'd be setting your data directly to this.cls.WeightMapCls.Weight_Map.Weights.


The source geometry would be set up as follows


The cloned emTopolizer geo is a very simple setup


You'll also need to have the emTools addon installed to blur the vertex data (which smooths out the extrusion). The amount of smoothing is down to artist choice but without smoothing the extrusion will be raw and jagged (maybe that's the look you want!). BTW, you don't have to use _ThickMul as your custom attribute, you can call it whatever you want; but be sure to add your custom attribute to the Thickenizer operator. You could also drive the extrusion directly by the colour of your texture map, but then you wouldn't be able to take advantage of the Blur Vertex Data operator.

[tarkovsky]

Thank you very much for your effort!

I only need to extrude the polygons in a "non-smooth" way, but I basically don't know how to convert the weights into clusters/arrays of polygons for the extrude topo node.



I'm not sure how the Thickenizer would be used. What would you write in the ICE Data field?

[jonmoore]

There's a demo scene included in the emTopolizer scene examples folder called Thickenizer_Torus2 and this shows the basic workflow. I've uploaded the scene here - https://d.pr/f/8kHQiq.rar -.

In the screenshot below I've adapted the demo scene to not use laplacian smoothing and have locked a couple of PPG's that contain essential info for making the effect work for what you're attempting (I've also created a weightmap targeting a single section of polygons to better mirror your objective).

I have a preference for the Thickenizer workflow as it provides more control and flexibility but you could also use the native operator - Apply Extrude Polygon Along Axis, using it's Is Element mode to target the weightmap. With either approach you need to ensure you set up your weightmap with a low base weight above zero (in my case I used 0.05), as this helps ensure you don't get any post extrusion artefacts. This means that you're effectively creating a shell from your geo (all polys get a micro extrusion, as well as your full weight target polygons). And this is another reason for my preference for Thickenizer, as it allows you create separate inner and outer extrusion values. And as you can see in the Thickenizer PPG it also provides inputs and outputs for UV and Color (as well as motion vectors), which helps with your overall ICE tree composition.

The most important aspect of this workflow is that you create your custom ICE attribute (in the demo scene example ' _ThickMul' on duplicate geometry (which you later hide). And then apply the extrusion on your target geo. Hope this clarifies things a little more.