PDA

View Full Version : How to create a 'cut out' character from a single poly...



kyleprometheus
10-11-2018, 10:08 AM
Hello fellow Lightwave Luminaries,

I want to create a character drawing on a single polygon. How do I 'knock out' the negative space around the character? ie. Like a cut out around the character and putting the rest of the paper in the bin.

The effect I want is to create a 2d character in a 3d world. (I also have some targa roof antennas textures, which have white backgrounds, to put on the top of buildings...which could use a similar effect, i.e. to knock out the white background space...)

143079

Like an alpha channel effect. Knock out the white but keep the black? (Also, will the silhouette cast a shadow in Lightwave 3D's 'staging/animation' when I push it through from Modeller?)

Appreciate any help you can give with this.

Regards,

Kyle.

Trevor
10-11-2018, 10:38 AM
Clip map in object properties, render tab, and yes, it will cast a shadow.

BeeVee
10-11-2018, 04:38 PM
Clip Map in the Surface Editor! A clip map is purely binary though, there's no smoothing the edges with anti-aliasing so make sure your clip is high enough resolution that the pixellation doesn't show.

B

Romizer
10-12-2018, 01:27 AM
i often use the transparency channel, so the image stays with the object and is not dependent on scenes.

BeeVee
10-12-2018, 01:43 AM
You haven't needed to do that since 2015. Clipmaps can be a surface property since then and thus saved with objects, not scenes.

B

Romizer
10-12-2018, 01:45 AM
Cool, i didn't know.

Thanks!

BeeVee
10-12-2018, 03:26 AM
The fact is that the old way of doing things had to be preserved for all the old content that used that method, and there might even be reasons to keep that way of doing things (particular assets that you want a different way of clip mapping) but Surface-based clip mapping is far more efficient in terms of workflow efficiency.

B

kyleprometheus
10-12-2018, 11:37 AM
Thank you to all the responses in this thread. A big help, thank you. :rock:

Thank you, especially to BeeVee(!) for taking the time to respond. Nice to get a response from NewTek's LightWave3D development team. :newtek:

I have managed to get clip maps working!

Ben, I've noted what you said regarding the resolution of the clip map. I'll make sure the original image files are at least print resolution of around 300 dpi.

It was cool to see my 2D character in the 3D environment. (I've put him on a ground disc inside a sky hemisphere...from a tutorial I got from youtube.) I've decided I really like clip maps. :cool:

Definitely having fun learning Lightwave 3D for the uses I have for it with comics. Getting the hang of UV maps, texturing and using the 'Drill' tool to create building details. :D

Regards,

Kyle.

jbrookes
10-12-2018, 01:02 PM
I suppose another method would be to use the Drill tool that you mentioned with a .EPS of your character.

It wouldn't be one polygon, but it would be perfectly flat if you worked on a plane. And you could get both the negative and positive space, depending on which Drill option you used.

Kryslin
10-12-2018, 02:20 PM
I often use both a clip map and a transparency map / alpha channel. The clip map takes care of the bulk of the transparent surface, while the transparency helps smooth out the jagged edges.

kyleprometheus
10-14-2018, 06:27 AM
I suppose another method would be to use the Drill tool that you mentioned with a .EPS of your character.

It wouldn't be one polygon, but it would be perfectly flat if you worked on a plane. And you could get both the negative and positive space, depending on which Drill option you used.

Hello J Brookes,

It would be cool if you knocked up an image or few to show the process of what you mean.

I find the 'cut out' 2D effect in a 3D world interesting. I know also, that in e.g. 'Bugs Life' for the ants they used 'poly plates' ('cut out' clipping/transparencies) to cut down on the scene geometry of a multitude of back ground ants. As long the image poly plane is facing the camera it is an efficiency to be aware of to create the illusion of 3D when it's really 2D to save resources at render time.

Though I like the idea of it being an 'obvious' effect too. (Not sure if I recall correctly, but I think they even show the 'cut outs' falling over as a comedy extra in the end credits...)

Regards,

Kyle.

kyleprometheus
10-14-2018, 06:33 AM
I often use both a clip map and a transparency map / alpha channel. The clip map takes care of the bulk of the transparent surface, while the transparency helps smooth out the jagged edges.

Hello Kristin,

I'd like to see you post a couple of images/or a step by step of how you do that if you can. I used a low res image just to test the concept. However, as per Ben's advice above, I'm sure if I use a high res' source 'clip/alpha' map in the 1st instance the 'jaggies' will smooth out? I will test the 'cut out' with a higher res render e.g. a black silhouette rendered in Poser 3D.

I did model a chain link fence back in 2001 with Softimage XSi during a 3D course I was doing. (I bought Lightwave 3D when I was on the course, actually, I wanted to use Lightwave and it was a great deal to buy it at the time...) Anyway, one of the fellow students on the course said those magic words, 'It would be a lot easier to use a clip map for the chain link fence.

I'd modelled it from a book and textured it with a rusty metal image map. But I can see there are efficiency in using clip maps and artistic merits in terms of creating a specific effect.

Regards,

Kyle.

Kryslin
10-14-2018, 08:00 AM
I'll see what I can come up with. My normal use for this is "hero" trees' leaves.

I you were to use a clip map of 4 or 8 times resolution, you could probably do without the transparency.

MonroePoteet
10-14-2018, 12:20 PM
If you're planning a many-framed animation of the cutout silhouettes, the EPS Drill method proposed by jbrookes may be too cumbersome. The basic method is to use a image editing tool (I use CorelDraw) to "vectorize" the B&W image using edge-detection, save it as Extended PostScript (EPS), then import it into Modeler and save out the resulting LW object. For one frame (or a logo) this is doable, but for many frames it may be too cumbersome.

To smooth the low-resolution clipmap without transparency, you could use the Image Editor=>Processing=>Add Filter=>Full Precision Blur filter to blur the silhouette image to be applied to the clipmap (and optionally transparency, see below). For example, here's a closeup of the head without the Full Precision Blur on the Image and the same with the filter applied using a 2x2-pixel horizontal and vertical "region" for the blur (LW2015 examples):

143092 No image blur

143093 Full Precision Blur image filter, 2x2 blur region

If you want to have the edges slightly transparent inside of the blurred clip map, you can use a high Mipmap Strength setting on the Transparency channel to merge the image pixels even more for Transparency inside the clip map:

143094 With Transparency, 10.0 Mipmap Strength

143098 Full figure, 10.0 Mipmap Strength

143095 With Transparency, 100.0 Mipmap Strength

143099 Full figure, 100.0 Mipmap Strength

Here's the setup for LW2015 with both the Image blurring and transparency:

143097

mTp

jbrookes
10-15-2018, 07:02 PM
Okay, so here are some images:

In this case, I just made my own closed curve out of points (figure 1):
143108

Then I put the curve into the background and drew a flat box in the foreground (figure 2):
143109

After choosing [Construct] -> [Drill] -> [Core] I ended up with a cutout (figure 3):
143110


And the resulting render (figure 4):
143111


Here's a nifty tutorial showing the EPS loader part of the process:
https://www.youtube.com/watch?v=BK8rL0GeKvY

mummyman
10-16-2018, 02:48 PM
I love using clip-maps. I wish they could be frozen out, or save transformed with the clips applied. Would make for a neat modeling tool. I think I put it as a feature request... but it's probably not doable in Layout? Or there isn't a big need for it.