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RussU

Open GL and Opacity

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HI everyone.

 

Quick workflow question. If I'm working in 3D perspective, Open GL, and I want to apply a transparancy to an object, like glass, without using a renderworks texture, what's the best way forward. Ideally I'd lie 25%-75% transparant so you can see it's there.

I've tried out a RW texture, and I like the "Draw Edges" view option, but it doesn't draw edges on the item with it applied. Everything else is ok.

 

Also, as a bonus, is there anyway of adding the RW style properties on to an object, without a Texture? (I can do line and fill, I want to do reflectivity and transparancy to on individual objects.

 

Thanks in advance

Edited by RussU

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3 hours ago, RussU said:

If I'm working in 3D perspective, Open GL, and I want to apply a transparancy to an object, like glass, without using a renderworks texture,


You must use a Renderworks texture, solid 3D objects in OpenGL do not respond to transparency from the attributes palette since they're taking it from their texture.

 

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4 hours ago, RussU said:

I've tried out a RW texture, and I like the "Draw Edges" view option, but it doesn't draw edges on the item with it applied. Everything else is ok.

 

Agreed! see this topic:

 

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In addition to the suggestions in the thread Andy linked, you could try applying a transparent texture to your object then duplicating it in place and removing its fill. It will then display as a wireframe in OpenGL (albeit without anti-aliasing, so the lines are a little jagged).

 

It's a bit of a workaround (and makes further edits a little tedious), but it kind of achieves what you're going for. Here's what it looks like in a rendered viewport:

 

A9RC6CD.jpg

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On 8/31/2017 at 3:19 PM, Luis M Ruiz said:

Mmh, adding reflectivity to individual objects? that's a good one.

Upon reading this my first thought was to agree it is a good idea as it could  avoid having to create multiple textures for different reflectivity settings for just a few objects. Otoh if you want to change reflectivity for multiple objects then changing a texture could be more convenient.

On second thought I think it would depend on the implementation. Would people want to have an option for object specific reflectivity on top of texture reflectivity or should this option be disabled if a texture has been applied (i.e. only possible in the original mentioned use case when no texture is applied).?

 

I.e there could be a potential issue that if an object has reflectivity applied separately from the texture's reflectivity then how would this interact. Override the texture's reflectivity, add/subtract into a combined reflectivity and if the latter, what if I want to have a fixed reflectivity that is a combination of texture and object settings, would it automatically adjust upon change of texture reflectivity to retain the "total" etc.?

 

I like the the idea, but am slighty worried it could become a recipe for a reflectivity mess if not properly implemented and people do not realize/notice there could be multiple reflectivity settings at work.

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On 21/10/2017 at 4:14 PM, Art V said:

it could become a recipe for a reflectivity mess

I agree completely.

One of the trick that I use with 3ds max is to have a master texture map, and then tweak the individual settings. So if I have, say, 5 of one item in a row they look like clones of each other, but nudge the bump map on each one, and tweak the individual reflectivity and glossiness settings, et voila, you now have 5 different versions of the same item. Looks much more natural.

Still looking to see RW have a more fluid workflow before I migrate my rendering into VW.

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20 hours ago, RussU said:

I agree completely.

One of the trick that I use with 3ds max is to have a master texture map, and then tweak the individual settings. So if I have, say, 5 of one item in a row they look like clones of each other, but nudge the bump map on each one, and tweak the individual reflectivity and glossiness settings, et voila, you now have 5 different versions of the same item. Looks much more natural.

Still looking to see RW have a more fluid workflow before I migrate my rendering into VW.

That would definitely be useful to have in Renderworks. For (technical) engineering items it may not be that much of an issue but for other types of items/objects I can see the benefit.

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For a fast rendering and unique looking style, I'd recommend using an artistic > cartoon. It represents the models well, with quick textures and edges and in my opinion with a  more fun look than OpenGL but still not a full photorealistic rendering. I've been using this cartoon style more and more lately, especially when creating early panoramas.

 

On this screenshot, you'll see Realistic on the left, artistic cartoon in the middle and OpenGL on the right.

 

Give it a try and post your test results.

 

 

cartoon vs opengl.png

Edited by Luis M Ruiz

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6 hours ago, Luis M Ruiz said:

For a fast rendering and unique looking style, I'd recommend using artistic > cartoon. It represents the models well, quick textures, edges and in my opinion is better than an OpenGL look but not full photorealistic rendering. I've been using this cartoon style more and more lately, especially when creating early panoramas.

 

On this screenshot, you'll see Realistic on the left, artistic cartoon in the middle and OpenGL on the right.

 

Give it a try and post your test results.

 

 

cartoon vs opengl.png

Luis; the cartoon seems an interesting approach, but the V-in-circle Logo in the middle item puts a damper on my enthusiasm. Can those facets be smoothed in Cartoon?

 

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The facets are controlled by the viewport resolution. I had the other two at 300dpi and rendered the cartoon at only 72dpi,  just to make a point on this post.

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wouldn't that be more down to the 3d conversion res? not the page res?

Just trying to understand the process a little more.

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On 10/26/2017 at 6:59 AM, Luis M Ruiz said:

The facets are controlled by the viewport resolution. I had the other two at 300dpi and rendered the cartoon at only 72dpi,  just to make a point on this post.

great, so if the viewport resolution is sufficient, the facets will be resolved, true story?

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9 hours ago, mjm said:

great, so if the viewport resolution is sufficient, the facets will be resolved, true story?

In general, if it isn't 3D conversion res or the Curved Geometry setting in the render style causing the faceting, then yes the rest of it usually comes from DPI.

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3 hours ago, JimW said:

In general, if it isn't 3D conversion res or the Curved Geometry setting in the render style causing the faceting, then yes the rest of it usually comes from DPI.

Thanks for the clarity (bad pun maybe?) there JimW.

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On 2017-10-20 at 8:40 PM, tsw said:

In addition to the suggestions in the thread Andy linked, you could try applying a transparent texture to your object then duplicating it in place and removing its fill. It will then display as a wireframe in OpenGL (albeit without anti-aliasing, so the lines are a little jagged).

 

It's a bit of a workaround (and makes further edits a little tedious), but it kind of achieves what you're going for. Here's what it looks like in a rendered viewport:

 

A9RC6CD.jpg

 

I also (often) use this rather clunky method to bypass the problem. I actually bug reported this some years back, bit was informed that it works as designed.

 

Let's say that we agreed to disagree whether this restriction was a good thing. To me, it makes no sense to delibetrately restrict a possible way for the designer to do their job as they like. 

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