Applying materials in a pattern based on image

[Chad Warner]

Ive got a 5000 seat arena with a pattern of 3 colors that they want to use for the seating. The pattern itself is too random to be able to do anything with, and the seats I have are proxied.

 

Does anyone know of a way to select seats based on pixel color of an image, or some other way to do this? I can't apply one big uvw map because the proxies are already created.

 

Any thoughts would be GREATLY appreciated.

 

-Chad

[erickdt]

Could you use the random select script?

 

http://www.scriptspot.com/3ds-max/scripts/random-select-v1-0

 

E

[Chad Warner]

Unfortunately, no. Here's an example of one of the seating areas.

[Crazy Homeless Guy]

I think I understand what you are trying to do.

 

The only thing I can think of it to bring the image into Photoshop, make the image gray scale, and adjust the levels so that you have 3 very distinct colors.

 

Then create a plane that corresponds to the seat, and the image size. Then displace that plane with the image that was adjusted in Photoshop.

 

Now use Soulburn's Object Dropper to drop the chairs onto that displaced plane.

 

Now simply select the chairs based upon where their height is on the plane. Everything on the bottom is color 1, everything in the middle is color 2, and everything at the top is color 3.

 

Now move the chairs back into the air, and set the inclined/stepped floor as the ground for the Soulburn Script, and drop the chairs back into their appropriateplace.

 

Not the most effecient or cleanest method, but it might work.

[Chad Warner]

Not the most effecient or cleanest method, but it might work.

 

At this point, anything is more efficient than hand picking chairs one at a time. I'll be insane by the time I'm done.

[Crazy Homeless Guy]

Unfortunately, no. Here's an example of one of the seating areas.

 

If you have CAD plan you might be able to extrude the colors, and then select by the color, and then use Soulburn's Object Replacer to replace the color with a corresponding colored chair.

 

Then use Object Dropper to drop the replaced chairs into place.

[Chad Warner]

CHG-

 

You're the man. I was able to get the displacement map to work effectively on the straight sections but not the angled sides, the initial map was a little low-res, so it just wasn't working too well over there. But it worked on the rectilinear sections like a champ.

[erickdt]

Unfortunately, no. Here's an example of one of the seating areas.

 

Hmmm. I guess I don't understand why you couldn't just do a random select, apply one of the colors to the random selection and then repeat until you've randomly applied all 4 or 5 colors.

 

Obviously you'd do the bottom few rows that are all the same color seperately.

 

E

[Peter M. Gruhn]

Rather than doing the dropping thing, you might have volume select perform that aspect.

 

Another idea.

 

Attach all the chairs into one object.

Use a texture map which is white mostly with black for one pattern color

UVW map. Planar. Fit.

Volume select. That map.

Delete mesh or Material (id) or something.

 

It worked on my test w/ 20x20 (400 total) boxes and a tile map w/ lots of variation.

[Chad Warner]

Hmmm. I guess I don't understand why you couldn't just do a random select, apply one of the colors to the random selection and then repeat until you've randomly applied all 4 or 5 colors.

 

Obviously you'd do the bottom few rows that are all the same color seperately.

 

E

 

The problem was that the pattern wasn't necessarily random, at least I didn't want to take the chance with it. Someone went to the trouble of laying out the 3 colors over the course of the entire arena, so I figured I'd better do the same with my materials.

[erickdt]

I see.

 

This is a situation where I'd ask myself whether or not it was worth the extra effort to ensure that this detail was represented correctly. There are alot of times that I get hung up on a detail of a rendering that nobody else other than me will even notice. At that point it becomes a question of cost (in terms of time) vs. benefit. In this particular case I'd ask myself if this seemingly random, very large pattern is even perceptible to the audience that will be viewing the render. Is there any time when all of the seating is seen by the viewer (where the pattern would be evident)? Just my 2c.

 

Anyway, another approach might be to originally have all of your chair proxies in a straight line (still tiered) and texture them that way and then somehow distribute them along splines or something that conform to the oval shape of the arena.

 

E

[Chad Warner]

Believe me, I was asking myself every minute if it was worth the time and trouble to match the pattern, because I'm about 95% sure that no one will notice if it's off or not. It's that other 5% that worried me though.

 

When I laid out the chairs to begin with, I started with Acad blocks and replaced them all with instances of my proxied chair. If I'd started with the colored pattern initially, I would have done the same thing, but in groups of color. It most likely wouldn't have been too difficult, other than I already had the chairs in place, and I only had a jpg of the seating color chart to work from.

Edited April 30, 2010 by Chad Warner