CompuServe Thread

#Extruding colors??

7 messages in this thread
#173956From: Dennis ConklinJun 6, 1995 1:53 PM
A question on a possible "weird" application of 3DS. I do finite element analysis of power plant components. One of the results that I obtain is usually a "pretty" color picture of the stress or temperature within the component. Typically the pictures are contours, with RED being the high stress region, BLUE being the low stress region, and a dozen or so intermediate colors showing intermediate regions. I am interested in modelling components so as to display the stress contours on the component. For example, assume that I am analyzing a boiler wall tube – it has combustion conditions on the front side, insulation on the backside, and steam thru the center of the hole. I would analyze this by making a 2-D model of the tube – basically a flat donut (a circle within a circle). After the analysis, I could obtain a picture of this flat donut with red areas of high stress, blue areas, intermediate areas, etc. However, it would be more dramatic for customer presentations if I could take this 2-D color picture of the tube cross-section and extrude it to actually create a 3-D model of some length of tube. What I would need is for the part of the tube which represents the red portion of the 2-D picture to be red material, the part that represents the blue portion of the 2-D picture to be blue material, etc. Is there a quick and dirty way to take this color picture of a 2-D cross-section and "extrude" it so that the extruded portions pick up the colors of the original 2-D cross-section?? I'm afraid that I must also ask for a possible method that works with one hand tied behind my back – I have the EDU version (v2) of 3DS, and I can get parttime access to v3, but I don't have v4, don't have any IPAS, etc. (I have ACAD12 though, for the modelling, if that helps!) Any hints would be appreciated – it may be that with my limited knowledge of 3DS (and limited docs you should see what the EDU version DOESN'T have!) I have overlooked some obvious technique. thanks for any clues, Dennis
#173962From: Dennis ConklinJun 6, 1995 2:14 PM
P.S. I realize I might have given a wrong (and overly ambitious) impression of my needs. I do not necessarily need to animate the extrusion – what I really need is a still picture of the modelled component with the appropriate colored materials – a flyby might be nice, but watching it extrude is not necessary. So this is a MODELLING question, not an animation question (let's not make it any harder than necessary). thanks again, for any hints] Dennis
#173966From: Rich SchwartzJun 6, 1995 2:33 PM
Dennis, If I understand your application, you want to take a two dimensional color contour plot of data (a bitmap, ie GIF, JPEG, TIFF or RAW) image and place it on a three dimensional surface. I have done this with color contour plots of data from pressure sensative paints and velocity measurment systems from wind tunnels. This is a simple application of texture mapping. Start by making a SCALE 3D model of your part. Then take the data and put it in a form 3DS will recognize (I usually convert my 1 byte integer data to a GIF bitmap), and create a material out of it in the Materials editor. I will make the material 100% self illuminating, and sometimes slightly transparent. Then the material is mapped onto the surface as any other texture map would be. The result is a contuor map applied directly to the three dimensional model. This task is easy and powerful, once you have a good understanding of texture mapping. I hope this a shot in the right direction. I have omitted several details, feel free to ask if you want them. Rich Schwartz
#174111From: Dennis ConklinJun 7, 1995 7:23 AM
Rich, Thanks – between you and David (other response) I think I understand – I don't know why it never occurred to me to use the picture as a material – duh!! (Probably because I was just thinking about it at work and 3DS is at home, along with all the books!) Dennis
#174331From: Rich SchwartzJun 8, 1995 10:24 AM
Dennis, A tip for mapping data… If your data does not cover the entire rectangular region of the bitmap, you can make any "empty space" black, or RGB 0,0,0 in the bitmap. Then in the materials editor, turn on the ADD (which disables SUB), and put the transparency of the material to 1 or higher. Now all of the black sections will become 100% transparent, leaving only the data (which is 99% opaque) to be visible. This has worked well for me. Rich
#173990From: David GouldJun 6, 1995 6:15 PM
<<I would analyze this by making a 2-D model of the tube – basically a flat donut (a circle within a circle). After the analysis, I could obtain a picture of this flat donut with red areas of high stress, blue areas, intermediate areas, etc. However, it would be more dramatic for customer presentations if I could take this 2-D color picture of the tube cross-section and extrude it to actually create a 3-D model of some length of tube.>> Take the image you made of the cross section with it's associated stresses. Crop the image so the tube touchs all of the edges of the bitmap. The height of the bitmap now represents the diameter of the tube. In 3DS create a tube with Create/Object/Tube with the exact dimensions of the tube you created in 2D. Then create a material using the cropped bitmap. Then using planar mapping assign this material to the front of the tube. Hint: use Surface/Mapping/Adjust/Scale with Alt+Click on the object to scale to the size of the front of the tube. The result will be the bitmap extended along the length of the tube as you want. DaviD "Red, yellow, orange, blue" GouID
#174112From: Dennis ConklinJun 7, 1995 7:23 AM
David, Ok, between you and Rich (other response) I understand – MAKE a MATERIAL from the plot – sometimes the answer is so simple that my peanut brain can't see it! thanks for the assist! Dennis