Advanced Properties 3D Models/ Camera Properties

I'm just babbling here to reach an understanding.

The Advanced tab of the 3D model window contains Normals properties settings. Some of the models I work with are just not that great. The minute you animate them or the camera "fireflies" tend to appear along the edges. I've noticed if I use From File + Auto Smoothing and adjust the degree angle that this tends to help with "fireflies" along the surface. 

Now question - Am I using the Generate Method for normals properly or am I not? 

Camera Properties - This is along the same line when it comes to "fireflies" along the model. Master Tony mentioned to me months ago that if I moved the Near Clipping Distance to 8.0 that this would help with fireflies when the model/camera is moving from a near distance. He indeed was correct.

Question - Is the clipping distanced measured in pixels?



  • First the easy one. Clipping distance is measured in pixels. The camera reach is 100,000 pixels--possibly more on a really badass GPU. Scale of a scene (pixels per inch/foot, etc) is determined by the artist (see Essential Hitfilm Cameras 1 for a longer discussion on scale). 

    Generate Normals... 

    Ok, picture a flat table. Stick a pencil in the center, perpendicular to the face. The table is a polygon, the pencil represents the normal. The normal is the point in the center of the polygon used to measure which way the poly faces relative to a camera or light source. So now picture a 3D model (make it simple, picture a lo-res sphere) with a little "quill" sticking out from the center of each poly. These quills show the direction of each face.

    So, how does a computer know if these flat polys are supposed to render as "smooth," like a sphere, or "flat," like a cube? The easiest way is "smoothing angle." Let's make smoothing angle 45. Any two faces joining with fewer than 45 degrees of angle between them are now defined as a smooth, contiguous surface. Any two faces meeting with more than 45 degrees of angle are different surfaces with a hard edge.

    So. Generating normals from file takes the geometry as-is and generates smoothing based on your input angle. 

    The above should help you determine if you are using generate normals "right."

    As far as issues with models, this is where @Aladdin4d or @NxVisualStudio have more knowledge than I. For fireflies it's sometimes Hitfilm rendering something odd, but, most of the time, it's an issue in the original model--especially free models. There are things 3D renderers don't like--such as odd numbers of edges meeting at the same vertex in a polar pattern, overlapping geometry, co-planar geometry, and very long, very thin polys. Often a downloaded model was created with bad geometry to start with and requires correction in a modeler before import.

    So. Can you upload a problematic model, or would that be giving away something you paid for? 

  • As I'd mention Master Tony had informed me about the normals a few months back but he didn't elaborate as fully as you have. Your explanation is what I though..but I wanted to be sure of what I thought...if you know what I mean.

    There isn't much talk about models and Hitfilm much so I wanted to get what I (think) I know into the public realm to possibly help other Hitfilm users with their modeling in the future.

    Thanks for the explanation sir. As on.

  • "There isn't much talk about models and Hitfilm much so I wanted to get what I (think) I know into the public realm to possibly help other Hitfilm users with their modeling in the future."

    I'm behind on where I intended to be with Essential Hitfilm, but, I have Cameras 4, Optimize Hitfilm for Workflow, Lights/Materials, Text, Tracking, Masking/Roto to go, which finishes up the Express features, then I go Pro-only starting with 3D models. If I can do over two hours on cameras you know I'll have a very detailed series on models. 

    Best tutorials for models are still Simon Jones' from HF2U. That's pre Cook-Torrance and THAT will be an important tutorial. 

    @HitfilmSensei of course is doing a model series, but you know this already. 

  • @Triem23 ; "...Lights/Materials, Text, Tracking,..."

    Whoa, maybe a good thing you had not yet gotten to text. Enough additions to require a redo given all the additions in HF6.

  • @NormanPCN Yeah, which is why I didn't stress too much before leaving for Antarctica. There are also enough changes in layer materials that would have required addenda.

    And I think that Optimization video we brainstormed on is going to get an upgrade to cover updating versions as well. Moving presets and things around between installations... Help all those lucky people getting Hitfilm Pro for Xmas optimize their new software... 

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