• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
NicoG

Error in GLSL: pow(f, e) will not work for negative f

2 posts in this topic

This is the error I get from YoYo's Game Maker:

############################################################################################ 
FATAL ERROR in Vertex Shader compilation 
ShaderName: sh_rimlighting 

C:\Users\xxxxx\AppData\Local\Temp\gm_ttt_77174\memory(182,8): warning X3571: pow(f, e) will not work for negative f, use abs(f) or conditionally handle negative values if you expect them 

at gml_Object_obj3DPlanet_Draw_0 (line 27) - shader_set( sh_rimlighting ); 
############################################################################################

 
This is the Vertex Shader I apply:

attribute vec3 in_Position;                  // (x,y,z) 
attribute vec4 in_Colour;                    // (r,g,b,a) 
attribute vec2 in_TextureCoord;              // (u,v) 
attribute vec3 in_Normal;                    // (x,y,z) 
  
varying vec2 v_vTexcoord; 
varying vec4 v_vColour; 
varying float dp; 
  
uniform float rim_power; //Increase to reduce the effect or decrease to increase the effect 
  
void main() 
{ 
    gl_Position = gm_Matrices[MATRIX_WORLD_VIEW_PROJECTION] * vec4( in_Position, 1.0); 
    
    v_vColour = in_Colour; 
    v_vTexcoord = in_TextureCoord; 
    
    vec3 wvPosition = normalize((gm_Matrices[MATRIX_WORLD_VIEW] * vec4(in_Position, 1.0)).xyz); 
    vec3 wvNormal = normalize((gm_Matrices[MATRIX_WORLD_VIEW] * vec4(in_Normal, 0.0)).xyz); 
    //float power = 5.0; //Increase to reduce the effect or decrease to increase the effect 
    dp = pow(dot(wvPosition, wvNormal) + 1.0, rim_power); 
}

This is the GML Code I call:
 

var rim_power = shader_get_uniform( sh_rimlighting, "rim_power" ); 
d3d_transform_add_rotation_x( 90 ); 
d3d_transform_add_rotation_y( planet_angle ); 
d3d_transform_add_scaling( planet_scale, planet_scale, planet_scale ); 
d3d_transform_add_translation( x, y + offset_y, 0 ); 
shader_set( sh_rimlighting ); 
shader_set_uniform_f( rim_power, 5.0 ); 
d3d_model_draw( modPlanet, 0, 0, 0, background_get_texture(tex_mars) ); 
shader_reset(); 
d3d_transform_set_identity();

I do not know where this error is coming from. If I uncomment "float power = 5.0" and use it instead of the uniform rim_power, then it works. 

I also get this error when I set rim power to any number that has anything different than .0 as last number. So e.g. 1.0 works, but 2.3 leads to this error. 

Any hint or insight is appreciated.

Edited by GothSeiDank
0

Share this post


Link to post
Share on other sites

X3571 is a warning, not a fatal error. However, Game Maker seems to regard it as an error.

 

The warning text does suggest two workarounds - if you're sure that the power never should be negative, use the abs function to clamp the value to a positive range, or otherwise make sure that the shader logic never allows the pow function to be called with a negative power parameter. The shader compiler can deduce whether or not the parameter can ever be negative, based on the code that manipulates it.

Edited by Nik02
0

Share this post


Link to post
Share on other sites

Thanks fixed it:

dp = pow(abs(dot(wvPosition, wvNormal) + 1.0), rim_power);
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0